Treatment-resistant and multi-therapy-resistant criteria for bipolar depression: consensus definition

Oral prolonged-release ketamine in treatment-resistant depression - A double-blind randomized placebo-controlled multicentre trial of KET01, a novel ketamine formulation - Clinical and safety results

INTRODUCTION

We investigated the antidepressant effects of a novel oral prolonged-release formulation of racemic ketamine (KET01) in patients suffering from treatment-resistant depression (TRD) as add-on therapy.

MATERIAL AND METHODS

Patients were randomized to an additional 160 mg/day or 240 mg/day KET01 or placebo for 14 days. The primary endpoint was change in Montgomery-Åsberg Depression Rating Scale (MADRS) scores from baseline to day 15. For treatment group comparisons, we used ANOVA with pairwise least squares mean difference tests in a mixed model repeated measures analysis.

RESULTS

Twenty-seven patients completed the double-blind protocol before trial premature termination due to poor recruitment during the COVID-19 pandemic. Mean (SD) MADRS scores on day 15 were 23 (10.32) in placebo, 25 (8.28) with 160 mg/day and 17 (10.32) with 240 mg/day KET01. MADRS change was numerically larger but statistically non-significant in the 240 mg/day KET01 group vs placebo on day 7 (-5.67; p = 00.106) and day 15 was (difference: 4.99; p = 00.15). In exploratory analysis, baseline leukocyte count correlated with response to KET01 (p = 00.01). Distribution of adverse event rates were comparable between the treatment arms. Safety analysis did not identify increased risk of suicidality, dissociation, hear rate, systolic and diastolic blood pressure associated with trial treatment.

DISCUSSION

Our results suggest that adjunctive oral administration of prolonged-release ketamine at a dose of 240 mg/day shows a positive, although statistically non-significant, trend towards antidepressant efficacy, however, the benefit could not be confirmed due to premature trial termination. Given its ease of use and low side effects, further trials are warranted to investigate this route of ketamine administration as a promising potential treatment of TRD.

How different definition criteria may predict clinical outcome in treatment resistant depression: Results from a prospective real-world study

Management of treatment-resistant depression (TRD) remains a major public health challenge, also due to the lack of a consensus around TRD definition. We investigated the impact of different definitions of TRD on identifying patients with distinct features in terms of baseline characteristics, treatment strategies, and clinical outcome. We conducted a prospective naturalistic study on 538 depressed inpatients. Patients were screened for treatment resistance by two TRD definitions: looser criteria (lTRD) and stricter criteria (sTRD). We compared baseline characteristics, treatment and clinical outcome between the TRD groups and their non-TRD counterparts. 52.97 % of patients were identified as lTRD, only 28.81 % met the criteria for sTRD. sTRD patients showed lower rates of remission and slower symptom reduction compared to non-TRD patients and received more challenging treatments. Surprisingly, patients identified as sTRD also exhibited lower rates of psychiatric comorbidities, including personality disorders, substance abuse, or alcohol misuse. Stricter TRD criteria identify patients with worse clinical outcomes. Looser criteria may lead to overdiagnosis and over treatment. Clinical features known to be possible risk factors for TRD, as psychiatric comorbidities, showed to be more suggestive of a "difficult to manage" depression rather than a proper TRD.

Factors associated with self-perceived treatment-resistance in bipolar disorder

Patients with bipolar disorder often report self-perceived treatment resistance. However, it is not known to what extent it is due to actual treatment resistance. The Juntendo University provides "Bipolar Disorder Treatment Rebuilding Program," in which patients with self-reported treatment resistant bipolar disorder are hospitalized for 2 weeks and undergo detailed examinations. In this study, we report our experience with the initial 43 patients hospitalized during the one and half years after the launch of the program. Among the patients who underwent full assessment, only one was regarded as having genuine treatment-resistant bipolar disorder without comorbidity. In other cases, ten were not diagnosed with bipolar disorder, 3 had organic brain diseases, 12 had comorbid mental disorders and its symptoms were regarded as treatment-resistant bipolar symptoms by the patients, and 18 did not receive adequate treatment because attendant physicians did not adhere to the treatment guidelines or patients did not adhere to the treatment because of lack of insight. The number of participants was not large, and selection bias hampered the generalization of the findings. Insight and adherence were assessed without the use of validated tools. We could not verify recovery after adequate treatment because of the limited hospitalization period. The findings suggest that most patients with self-perceived treatment-resistant bipolar disorder may not have genuine treatment-resistant bipolar disorder. These results shed light on the difficulties of public education of bipolar disorder and importance of providing appropriate services for diagnosis and treatment of bipolar disorder in the community.

Single-Dose Synthetic Psilocybin With Psychotherapy for Treatment-Resistant Bipolar Type II Major Depressive Episodes: A Nonrandomized Controlled Trial

Importance

Bipolar II disorder (BDII) is a debilitating condition frequently associated with difficult-to-treat depressive episodes. Psilocybin has evidence for rapid-acting antidepressant effects but has not been investigated in bipolar depression.

Objective

To establish the safety and efficacy of psilocybin in patients with BDII in a current depressive episode.

Design, Setting, and Participants

This was a 12-week, open-label nonrandomized controlled trial conducted at Sheppard Pratt Hospital. Participants aged 18 to 65 years with BDII, a current depressive episode longer than 3 months, and documented insufficient benefit with at least 2 pharmacologic treatments during the current episode were invited to participate. Of 70 approached, 19 met inclusion criteria and were enrolled. The trial was conducted between April 14, 2021, and January 5, 2023.

Interventions

A single dose of synthetic psilocybin, 25 mg, was administered. Psychotropic medications were discontinued at least 2 weeks prior to dosing. Therapists met with patients for 3 sessions during pretreatment, during the 8-hour dosing day, and for 3 integration sessions posttreatment.

Main Outcomes and Measures

The primary outcome measure was change in Montgomery-Åsberg Depression Rating scale (MADRS) at 3 weeks posttreatment. Secondary measures included MADRS scores 12 weeks posttreatment, the self-rated Quick Inventory of Depression Symptoms-Self Rating (QIDS-SR), and the self-rated Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF), each completed at baseline and all subsequent visits. Safety measures included the Columbia Suicide Severity Rating Scale (CSSRS) and the Young Mania Rating Scale (YMRS) completed at each visit.

Results

Of the 15 participants in this study (6 male and 9 female; mean [SD] age, 37.8 [11.6] years), all had lower scores at week 3, with a mean (SD) change of -24.00 (9.23) points on the MADRS, (Cohen d = 4.08; 95% CI, -29.11 to -18.89; P < .001). Repeat measures analysis of variance showed lower MADRS scores at all tested posttreatment time points, including the end point (Cohen d = 3.39; 95% CI, -33.19 to -16.95; adjusted P < .001). At week 3, 12 participants met the response criterion (50% decrease in MADRS), and 11 met remission criterion (MADRS score ≤10). At the study end point, 12 patients met both response and remission criteria. QIDS-SR scores and Q-LES-Q-SF scores demonstrated similar improvements. YMRS and CSSRS scores did not change significantly at posttreatment compared to baseline.

Conclusions and Relevance

The findings in this open-label nonrandomized controlled trial suggest efficacy and safety of psilocybin with psychotherapy in BDII depression and supports further study of psychedelics in this population.

Ketamine for bipolar depression: an updated systematic review

Background

The therapeutic potential of subanesthetic doses of ketamine appears promising in unipolar depression; however, its effectiveness in treating bipolar depression (BD) remains uncertain.

Objective

This systematic review aimed to summarize findings on the use of ketamine for the treatment of BD by assessing its efficacy, safety, and tolerability.

Design

Systematic review.

Methods

We conducted a systematic review of studies that investigated the use of ketamine for adults with BD. We searched PubMed and Embase for relevant randomized-controlled trials, open-label trials, and retrospective chart analyses published from inception to 13 March 2023.

Results

Eight studies were identified [pooled n = 235; mean (SD) age: 45.55 (5.54)]. All participants who received intravenous (IV) ketamine were administered a dose of 0.5-0.75 mg/kg as an adjunctive treatment to a mood-stabilizing agent, whereas participants who received esketamine were administered a dosage ranging from 28 to 84 mg. Flexible dosing was used in real-world analyses. A total of 48% of participants receiving ketamine achieved a response (defined as ⩾50% reduction in baseline depression severity), whereas only 5% achieved a response with a placebo. Real-world studies demonstrated lower rates of response (30%) compared to the average across clinical trials (63%). Reductions in suicidal ideation were noted in some studies, although not all findings were statistically significant. Ketamine and esketamine were well tolerated in most participants; however, six participants (2% of the overall sample pool, 5 receiving ketamine) developed hypomanic/manic symptoms after infusions. Significant dissociative symptoms were observed at the 40-min mark in some trials.

Conclusion

Preliminary evidence suggests IV ketamine as being safe and effective for the treatment of BD. Future studies should focus on investigating the effects of repeated acute and maintenance infusions using a randomized study design.

Systemic Inflammatory Response Index (SIRI) at Baseline Predicts Clinical Response for a Subset of Treatment-Resistant Bipolar Depressed Patients

Background: in a recent double-blind, placebo controlled RCT we demonstrated that selective inhibition of cyclo-oxygenase 2 (COX2) is an effective adjunctive strategy in treatment-resistant bipolar depression (TRBDD). To better clarify the mechanisms underlying TRBDD and treatment response, we conducted a retrospective exploratory analysis of the systemic inflammatory response index (SIRI = absolute neutrophils × absolute monocytes/absolute lymphocytes) in relation to other biomarkers and clinical outcomes after escitalopram (ESC), combined with the COX-2 inhibitor, celecoxib (CBX), versus placebo. Methods: Baseline measures of SIRI were compared between TRBDD and healthy controls (HC), and correlated with blood-based inflammatory cytokines, kynurenines, and growth factors. Post-treatment Hamilton Depression Rating Scale 17 (HAMD-17) total scores (clinical outcome) were modelled according to SIRI adjusting for demographics (including relevant interactions with SIRI), baseline depression, treatment arm, and treatment timepoint using multiple linear regression and robust linear mixed effects models. Results: Baseline SIRI did not distinguish TRBDD from HC groups. Baseline SIRI was significantly correlated with lower baseline MCP-1. The relationship between SIRI and HAMD-17 was significant at treatment week 8, in contrast to baseline. Finally, baseline SIRI predicted elevated post-treatment HAMD-17 scores, amongst patients with elevated depression scores at baseline. Significance: High pre-treatment SIRI may predict poorer depressive outcomes amongst TRBDD patients with baseline elevated depression.

Single nucleotide polymorphisms in C-reactive protein (CRP) predict response to adjunctive celecoxib treatment of resistant bipolar depression

Background

Affective illness has been associated with a proinflammatory state, and it is generally accepted that the immune system plays a key role in the pathophysiology of mood disorders. Since inflammatory biomarkers are elevated in bipolar disorder, anti-inflammatory combination therapies may enhance response and reverse treatment resistance.

Purpose

In the present study we investigated the possible impact of single nucleotide polymorphisms (SNPs) within the CRP gene on CRP blood levels, treatment response and level-of-stress perception in our cohort of treatment-resistant bipolar-depressed patients receiving escitalopram and celecoxib, or escitalopram and placebo, as previously reported (Halaris et al., 2020).

Methods

Study design, clinical findings, and CRP blood levels have been reported previously (Halaris et al., 2020; Edberg et al., 2018). In this follow-up study we extracted DNA from blood cells collected at baseline. Genome-wide genotyping was performed for all subjects using the Infinium Multi-Ethnic Global-8 v1.0 Kit. Based on reports in the literature indicating possible associations with psychiatric conditions, ten previously reported CRP gene polymorphisms were evaluated in a preliminary analysis. We focused on rs3093059 and rs3093077 were in complete LD. Carriers were defined as those possessing at least one C allele for rs3093059, or at least one G allele for rs3093077. Additionally, we determined blood levels of the medications administered.

Results

Non-carriers of rs3093059 and rs3093077 had significantly lower baseline CRP blood levels than carriers (p = 0.03). Increased rates of HAM-D17 response (p = 0.21) and remission (p = 0.13) and lower PSS-14 scores (p = 0.13) were observed in non-carriers among subjects receiving celecoxib but they did not reach statistical significance. When examining all subjects, nominally significant associations between carrier-status and remission (p = 0.04) and PSS-14 scores (p = 0.04) were observed after correcting for treatment arm. Non-carriers receiving celecoxib had the highest rates of response and remission, and the lowest stress scores.

Conclusions

Carriers of the CRP SNPs may have higher baseline CRP levels, although non-carriers appear to benefit more from celecoxib co-therapy. Determination of the carrier status in conjunction with pretreatment blood CRP level measurement may contribute to personalized psychiatric practice, but replication of the present findings is needed.

Deep brain stimulation and digital monitoring for patients with treatment-resistant schizophrenia and bipolar disorder: A case series

AIM

The use of deep brain stimulation (DBS) has been recently extended for treating resistant psychiatric disorders, but the experience in patients with schizophrenia-related disorders and bipolar disorder (BD) is scarce.

METHOD

We conducted an observational, one-year longitudinal study to evaluate the effects of DBS in four treatment-resistant patients with schizophrenia, schizoaffective, and BD, included in a pilot, last-resource protocol. Patients were digitally monitored for objective assessment of behavioral changes.

RESULTS

After one year of its initiation, DBS of the nucleus accumbens (in subjects N2, N3, and N4) and subgenual anterior cingulate cortex (in N1) produced a significant clinical improvement, associated with decreases in the Clinical Global Impression (from 5.25±0.5 to 3.5±1, p=0.035) and in the Hamilton Depression Rating Scale (HADRS scores, from 14.5±6.56 to 1.5±1.29, p=0.020). We observed a notable, durable therapeutic response in two patients from this cohort (N1 and N3), a clinically relevant relief in a third (N2), and a lack of a significant response in the last one (N4). Maintenance electroconvulsive therapy sessions could be discontinued in the three patients that responded to DBS (N1-3). There were no side effects or relevant changes in cognitive functioning. There were relevant differences between physical activity and sleep time among the four participants.

CONCLUSIONS

These results suggest initial evidence that DBS may be an effective and safe alternative for treating complex and resistant forms of schizophrenia-related disorders and BD. Digital monitoring may help to capture objective measures of behavioral changes after the intervention.

Role of FKBP5 and its genetic mutations in stress-induced psychiatric disorders: an opportunity for drug discovery

Stress-induced mental health disorders are affecting many people around the world. However, effective drug therapy for curing psychiatric diseases does not occur sufficiently. Many neurotransmitters, hormones, and mechanisms are essential in regulating the body's stress response. One of the most critical components of the stress response system is the hypothalamus-pituitary-adrenal (HPA) axis. The FKBP prolyl isomerase 51 (FKBP51) protein is one of the main negative regulators of the HPA axis. FKBP51 negatively regulates the cortisol effects (the end product of the HPA axis) by inhibiting the interaction between glucocorticoid receptors (GRs) and cortisol, causing reduced transcription of downstream cortisol molecules. By regulating cortisol effects, the FKBP51 protein can indirectly regulate the sensitivity of the HPA axis to stressors. Previous studies have indicated the influence of FKBP5 gene mutations and epigenetic changes in different psychiatric diseases and drug responses and recommended the FKBP51 protein as a drug target and a biomarker for psychological disorders. In this review, we attempted to discuss the effects of the FKBP5 gene, its mutations on different psychiatric diseases, and drugs affecting the FKBP5 gene.

Celecoxib for Mood Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The effects of celecoxib on a broad spectrum of mood disorders and on inflammatory parameters have not yet been comprehensively evaluated. The aim of this study was to systematically summarize the available knowledge on this topic. Data from both preclinical and clinical studies were analyzed, considering the efficacy and safety of celecoxib in the treatment of mood disorders, as well as the correlation of inflammatory parameters with the effect of celecoxib treatment. Forty-four studies were included. We found evidence supporting the antidepressant efficacy of celecoxib in a dose of 400 mg/day used for 6 weeks as an add-on treatment in major depression (SMD = -1.12 [95%Cl: -1.71,-0.52], p = 0.0002) and mania (SMD = -0.82 [95% CI:-1.62,-0.01], p = 0.05). The antidepressant efficacy of celecoxib in the above dosage used as sole treatment was also confirmed in depressed patients with somatic comorbidity (SMD = -1.35 [95% CI:-1.95,-0.75], p < 0.0001). We found no conclusive evidence for the effectiveness of celecoxib in bipolar depression. Celecoxib at a dose of 400 mg/d used for up to 12 weeks appeared to be a safe treatment in patients with mood disorders. Although an association between celecoxib response and inflammatory parameters has been found in preclinical studies, this has not been confirmed in clinical trials. Further studies are needed to evaluate the efficacy of celecoxib in bipolar depression, as well as long-term studies evaluating the safety and efficacy of celecoxib in recurrent mood disorders, studies involving treatment-resistant populations, and assessing the association of celecoxib treatment with inflammatory markers.

Diagnosis and management of bipolar disorders

Bipolar disorders (BDs) are recurrent and sometimes chronic disorders of mood that affect around 2% of the world's population and encompass a spectrum between severe elevated and excitable mood states (mania) to the dysphoria, low energy, and despondency of depressive episodes. The illness commonly starts in young adults and is a leading cause of disability and premature mortality. The clinical manifestations of bipolar disorder can be markedly varied between and within individuals across their lifespan. Early diagnosis is challenging and misdiagnoses are frequent, potentially resulting in missed early intervention and increasing the risk of iatrogenic harm. Over 15 approved treatments exist for the various phases of bipolar disorder, but outcomes are often suboptimal owing to insufficient efficacy, side effects, or lack of availability. Lithium, the first approved treatment for bipolar disorder, continues to be the most effective drug overall, although full remission is only seen in a subset of patients. Newer atypical antipsychotics are increasingly being found to be effective in the treatment of bipolar depression; however, their long term tolerability and safety are uncertain. For many with bipolar disorder, combination therapy and adjunctive psychotherapy might be necessary to treat symptoms across different phases of illness. Several classes of medications exist for treating bipolar disorder but predicting which medication is likely to be most effective or tolerable is not yet possible. As pathophysiological insights into the causes of bipolar disorders are revealed, a new era of targeted treatments aimed at causal mechanisms, be they pharmacological or psychosocial, will hopefully be developed. For the time being, however, clinical judgment, shared decision making, and empirical follow-up remain essential elements of clinical care. This review provides an overview of the clinical features, diagnostic subtypes, and major treatment modalities available to treat people with bipolar disorder, highlighting recent advances and ongoing therapeutic challenges.

Efficacy of short-term psychodynamic psychotherapy (STPP) in depressive disorders: A systematic review and meta-analysis

INTRODUCTION

Depression is one of the leading diseases globally. It can severely interfere with daily and occupational functioning of people affected. Both pharmacological interventions and psychotherapy are used for adult depression. The aim of the review is to evaluate the efficacy of short-term psychodynamic psychotherapy (STPP) by comparing STPP with different types of interventions.

MATERIALS AND METHODS

A systematic review with meta-analysis on the efficacy of STPP in depressive disorders was performed.

RESULTS

Meta-analysis findings confirm the superiority of STPP versus no interventions. The average effect size of depressive symptoms severity at the end of the treatment is -0.91 (95% CI: -1.49 - -0.33) in favor of STPP, while for clinical improvement of depressive symptoms is -0.78 (95% CI: -1.56 - 0.01). Results confirm a clear superiority of STPP to usual treatments unstructured. A mild superiority of efficacy of STPP on support psychotherapy emerged. Comparison of the efficacy of STPP vs cognitive-behavioral psychotherapy (CBT) shows little superior in case of STPP. No substantial differences in efficacy in case of STPP than control interventions emerged. Antidepressant therapy is resulted to be slightly more effective to STPP.

DISCUSSION

While all the other results confirm current literature, this review shows no superiority of combined treatment than STPP only.

LIMITATIONS

The review has some limitations such as the lack of moderation analysis and the high heterogenicity of the type of the studies.

CONCLUSIONS

The results confirm the efficacy of STPP in depressive disorders and endorse the guidelines of National Institute for Health and Clinical Excellence (NICE).

Real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression

BACKGROUND

Clinical trials have demonstrated rapid antidepressant effects with intravenous (IV) ketamine for major depressive disorder, with relatively less research specifically for bipolar depression. Herein, we describe the real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression.

METHODS

This study was conducted in a community clinic in Mississauga, Ontario (Canadian Rapid Treatment Centre of Excellence; Braxia Health). In this observational study (NCT04209296), patients with treatment-resistant bipolar I/II depression (n = 66) received four sub-anesthetic doses of IV ketamine (0.5-0.75 mg/kg) over a two-week period. Symptoms of depression, suicidality, anxiety, and functioning were assessed with validated self-report measures.

RESULTS

Statistically and clinically significant antidepressant effects were observed in the overall sample, as measured by the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR16 ) with further reductions in depressive symptoms observed after each subsequent infusion (n = 66; mean QIDS-SR16 reduction of 6.08+/-1.39; p < 0.0001). Significant reductions of suicidal thoughts (QIDS-SR16 -Suicide Item) and anxiety (Generalized Anxiety Disorder-7) were also observed with functional improvements on the Sheehan Disability Scale (p < 0.0001 on all measures). Moreover, the response rate (QIDS-SR16 total score decrease ≥50% from baseline) was 35% and remission rate (QIDS-SR16 total score ≤5) was 20% after four infusions. Infusions were generally well tolerated with treatment-emergent hypomania observed in only three patients (4.5%) with zero cases of mania or psychosis.

CONCLUSIONS

Real-world effectiveness of IV ketamine for bipolar depression was observed. Repeated doses were associated with greater symptom reduction and adequate tolerability.

Illness progression in older-age bipolar disorder: Exploring the applicability, dispersion, concordance, and associated clinical markers of two staging models for bipolar disorder in an older population

OBJECTIVES

The validity and applicability of two existing staging models reflecting illness progression have been studied in bipolar disorder (BD) in adults, but not in older adult populations. Staging model A is primarily defined by the number and recurrence of mood episodes, model B is defined by the level of inter-episodic functioning. This study aimed to explore the applicability, dispersion, and concordance of, and associations with clinical markers in these two staging models in older-age bipolar disorder (OABD).

METHODS

Using cross-sectional data from the Dutch Older Bipolars study, OABD outpatients (N = 126, ≥50 years) were staged using models A and B. Dispersion over the stages and concordance between the models were assessed. Associations were explored between model stages and clinical markers (familial loading, childhood abuse, illness duration, episode density, treatment resistance, Mini-Mental State Examination, and composite cognitive score).

RESULTS

Ninety subjects could be assigned to model A, 111 to model B, 80 cases to both. The majority (61%) had multiple relapses (model A, stage 3C) but were living independently (model B, stage I-III). Concordance between models was low. For model A, the markers childhood abuse, illness duration, and episode density significantly increased over subsequent stages. Model B was not associated with a significant change in any marker.

CONCLUSIONS

Assigning stages to OABD subjects was possible for both models, with age-related adjustments for model B. Model B as currently operationalized may be less suitable for OABD or may measure different aspects of illness progression, reflected by its low correspondence with model A and lack of associated clinical markers.

Comorbidity of adult ADHD and substance use disorder in a sample of inpatients bipolar disorder in Iran

BACKGROUNDS

The study of the relationship between adult Attention deficit hyperactivity disorder (ADHD) and bipolar disorder has received more attention in recent years and there is limited information in this area. On the other hand, there is a significant comorbidity between ADHD and bipolar disorder with substance use disorder. In this study, we investigated the prevalence of comorbidity of adult ADHD and substance use disorder among a group of bipolar patients admitted to a psychiatric hospital.

METHODS

One hundred fifty patients from a total of 200 consecutive patients who were referred to the emergency department of Roozbeh Psychiatric Hospital in Tehran, diagnosed with bipolar disorder based on the initial psychiatric interview and needed hospitalization, were evaluated again by an experienced faculty member psychiatrist by using a subsequent interview based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition(DSM-5). They were evaluated using the Structured Clinical Interview for DSM-5 (SCID-5) questionnaire to confirm the diagnosis of bipolar disorder and the comorbidity of adult ADHD and substance use disorder.

RESULTS

From 150 patients diagnosed with bipolar disorder, 106 patients (70.7%) had adult ADHD. 89 patients (59.3%) had substance use disorder and 58 patients (38.7%) had both of these comorbidities with bipolar disorder. Comorbidity of adult ADHD was associated with the earlier onset of the first mood episode in bipolar disorder (p value = 0.025). There was no statistically significant relationship between substance use disorder and age of onset of the first episode. (P value = 0.57).

CONCLUSIONS

Due to the limitations of studies on adult ADHD comorbidity with bipolar disorder, especially in hospital settings, as well as the increased risk of association with substance use disorder, further multicenter studies in this area with larger sample sizes can increase awareness in this regard.

Care pathways for people with major depressive disorder: a European Brain Council Value of Treatment study

Background

Despite well-established guidelines for managing major depressive disorder, its extensive disability burden persists. This Value of Treatment mission from the European Brain Council aimed to elucidate the nature and extent of “gaps” between best-practice and current-practice care, specifically to:Identify current treatment gaps along the care pathway and determine the extent of these gaps in comparison with the stepped-care model and Recommend policies intending to better meet patient needs (i.e., minimize treatment gaps).

Methods

After agreement upon a set of relevant treatment gaps, data pertaining to each gap were gathered and synthesized from several sources across six European countries. Subsequently, a modified Delphi approach was undertaken to attain consensus among an expert panel on proposed recommendations for minimizing treatment gaps.

Results

Four recommendations were made to increase the depression diagnosis rate (from ~50% episodes), aiming to both increase the number of patients seeking help, and the likelihood of a practitioner to correctly detect depression. These should reduce time to treatment (from ~1 to ~8 years after illness onset) and increase rates of treatment; nine further recommendations aimed to increase rates of treatment (from ~25 to ~50% of patients currently treated), mainly focused on targeting the best treatment to each patient. To improve follow-up after treatment initiation (from ~30 to ~65% followed up within 3 months), seven recommendations focused on increasing continuity of care. For those not responding, 10 recommendations focused on ensuring access to more specialist care (currently at rates of ~5–25% of patients).

Conclusions

The treatment gaps in depression care are substantial and concerning, from the proportion of people not entering care pathways to those stagnating in primary care with impairing and persistent illness. A wide range of recommendations can be made to enhance care throughout the pathway.

Use of 30-Hz Accelerated iTBS in Drug-Resistant Unipolar and Bipolar Depression in a Public Healthcare Setting: A Case Series

Background: Depressive episodes, especially when resistant to pharmacotherapy, are a hard challenge to face for clinicians and a leading cause of disability worldwide. Neuromodulation has emerged as a potential therapeutic option for treatment-resistant depression (TRD), in particular transcranial magnetic stimulation (TMS). In this article, we present a case series of six patients who received TMS with an accelerated intermittent theta-burst stimulation (iTBS) protocol in a public healthcare setting. Methods: We enrolled a total number of six participants, affected by a treatment-resistant depressive episode, in either Major Depressive Disorder (MDD) or Bipolar Disorder (BD). Patients underwent an accelerated iTBS protocol, targeted to the left dorsolateral prefrontal cortex (DLPFC), 3-week-long, with a total of 6 days of overall stimulation. On each stimulation day, the participants received 3 iTBS sessions, with a 15-min pause between them. Patients were assessed by the Hamilton Rating Scale for Depression (HAM-D), the Montgomery-Asberg Depression Rating Scale (MADRS), the Hamilton Rating Scale for Anxiety (HAM-A), and the Mania Rating Scale (MRS). At baseline (T0), at the end of the second week (T1), and at the end of the cycle of stimulation (T2). Results: The rANOVA (repeated Analysis of Variance) statistics showed no significant effect of time on the rating scale scores, with a slight decrease in MADRS scores and a very slight increase in HAM-A and HAM-D scores. No manic symptoms emerged during the entire protocol. Conclusions: Although accelerated iTBS might be considered a less time-consuming strategy for TMS administration, useful in a public healthcare setting, our results in a real-word six-patient population with TRD did not show a significant effect. Further studies on wider samples are needed to fully elucidate the potential of accelerated iTBS protocols in treatment-resistant depression.

Case report: Effectiveness of brexpiprazole and esketamine/ketamine combination: A novel therapeutic strategy in five cases of treatment-resistant depression

A significant proportion of patients with treatment-resistant depression do not attain functional recovery despite administration of multiple steps of pharmacotherapeutic strategies. This highlights the elusiveness of meeting unmet needs in existing pharmacotherapies for treatment-resistant depression. There is accumulating evidence that antidepressant agents involving the glutamatergic system such as brexpiprazole and esketamine/ketamine have more rapid onset of action and potentially improved effectiveness as an augmentation therapy in treatment-resistant depression. This case series aimed to report five complex cases of unipolar and bipolar treatment-resistant depression where conventional treatment strategies were inadequate in managing high risk suicidal behavior and achieving functional recovery. We discussed further the possible synergistic mechanisms of the novel combination strategy of brexpiprazole and esketamine/ketamine, clinical and patient factors that influenced treatment response, challenges with this combination strategy and implications for future practice and research.

A piece of the puzzle: Does bipolarity partly explain the high prevalence of treatment resistance in depression?

In this cross-sectional study we examined whether the prevalence of treatment resistant depression (TRD) can be partly attributed to level of bipolarity. We included data of 201 patients with either episodic depression or TRD, who received treatment for their depression at either an outpatient or 2nd opinion/daytime setting, within a specialised mental healthcare department in the Netherlands. Whether level of TRD, assessed by the 'Dutch Measure for quantification of Treatment Resistance in Depression', can be partly explained by level of bipolarity, assessed by 'the Bipolarity Index', was examined using linear regression. We found no direct association between level of TRD and level of bipolarity, nor did comorbid anxiety disorders obscure an existing association. In this study we found no evidence for overlooked bipolarity contributing to the high prevalence of TRD. If replicated, we could state that additional screening on bipolarity with an instrument such as the 'Bipolarity Index' in the specialised mental health care is unnecessary.

Treatment resistance in psychiatry: state of the art and new directions

Treatment resistance affects 20-60% of patients with psychiatric disorders; and is associated with increased healthcare burden and costs up to ten-fold higher relative to patients in general. Whilst there has been a recent increase in the proportion of psychiatric research focussing on treatment resistance (R² = 0.71, p < 0.0001), in absolute terms this is less than 1% of the total output and grossly out of proportion to its prevalence and impact. Here, we provide an overview of treatment resistance, considering its conceptualisation, assessment, epidemiology, impact, and common neurobiological models. We also review new treatments in development and future directions. We identify 23 consensus guidelines on its definition, covering schizophrenia, major depressive disorder, bipolar affective disorder, and obsessive compulsive disorder (OCD). This shows three core components to its definition, but also identifies heterogeneity and lack of criteria for a number of disorders, including panic disorder, post-traumatic stress disorder, and substance dependence. We provide a reporting check-list to aid comparisons across studies. We consider the concept of pseudo-resistance, linked to poor adherence or other factors, and provide an algorithm for the clinical assessment of treatment resistance. We identify nine drugs and a number of non-pharmacological approaches being developed for treatment resistance across schizophrenia, major depressive disorder, bipolar affective disorder, and OCD. Key outstanding issues for treatment resistance include heterogeneity and absence of consensus criteria, poor understanding of neurobiology, under-investment, and lack of treatments. We make recommendations to address these issues, including harmonisation of definitions, and research into the mechanisms and novel interventions to enable targeted and personalised therapeutic approaches.

Treatment-Resistant Bipolar Depression: Therapeutic Trends, Challenges and Future Directions

INTRODUCTION

Bipolar disorder (BD) is a chronic mental illness impacting 1-2% of the population worldwide and causing high rates of functional impairment. Patients with BD spend most of their time in depressive episodes and up to one-third of patients do not respond to adequate doses of medications. Although no consensus exists for definition of treatment-resistant bipolar depression (TRBD), failure of symptoms improvement despite an adequate trial of two therapeutic agents is a common theme of TRBD. In this paper, we review the evidence base of therapeutic interventions, challenges, and potential future directions for TRBD.

METHODS

We conducted a literature search for randomized controlled trials on PubMed for the treatment of TRBD and ongoing trials for the treatment of TRBD/bipolar depression on clinicaltrials.gov.

RESULTS

Several therapeutic agents have been investigated for TRBD. Adjunctive pramipexole and modafinil have data supporting short-term efficacy in TRBD, along with limited data for racemic intravenous ketamine. Celecoxib augmentation of escitalopram and treatment with metformin in patients with insulin resistance showed promising results. Right unilateral electroconvulsive therapy displayed statistically significant response rate and improvement, but not remission compared to pharmacotherapy. Trials for transcranial magnetic stimulation (TMS) have failed to show a significant difference from sham treatment in TRBD.

FUTURE TRENDS

Pharmacological treatments with novel mechanisms of actions like brexpiprazole and vortioxetine are being investigated following successes in unipolar depression. Modified TMS protocols such as accelerated TMS are under investigation. Innovative approaches like psychedelic-assisted psychotherapy, interleukin-2, fecal microbiota transplantation and multipotent stromal cells are being studied.

CONCLUSION

Evidence on current treatment modalities for TRBD is limited with low efficacy. More research is needed for successful treatment of TRBD. Effective therapies and innovative approaches to treatment are being investigated and could show promise.

Consensus on nomenclature for clinical staging models in bipolar disorder: A narrative review from the International Society for Bipolar Disorders (ISBD) Staging Task Force

OBJECTIVES

Clinical staging is widely used in medicine to map disease progression, inform prognosis, and guide treatment decisions; in psychiatry, however, staging remains a hypothetical construct. To facilitate future research in bipolar disorders (BD), a well-defined nomenclature is needed, especially since diagnosis is often imprecise with blurred boundaries, and a full understanding of pathophysiology is lacking.

METHODS

Under the auspices of the International Society of Bipolar Disorders, a Task Force of international experts was convened to review, discuss, and integrate findings from the scientific literature relevant to the development of a consensus staging model and standardize a terminology that could be used to advance future research including staging of BD and related disorders.

RESULTS

Consensus opinion and areas of uncertainty or difference were identified in regard to terms referring to staging as it may apply to BD, to at-risk status and subthreshold stages, and to various clinical stages of BD as it is currently diagnosed.

CONCLUSION

The use of a standardized nomenclature about the clinical stages of BD will facilitate communication about research on clinical and pathological components of this heterogeneous group of disorders. The concepts presented are based on current evidence, but the template provided allows for further refinements as etiological advances come to light.

The Choice of Either Quetiapine or Aripiprazole as Augmentation Treatment in a European Naturalistic Sample of Patients With Major Depressive Disorder

BACKGROUND

Augmentation with second-generation antipsychotics (SGAs) represents an evidence-based psychopharmacotherapeutic strategy recommended in case of insufficient response to the first-line antidepressant (AD) treatment in major depressive disorder (MDD). Comparative evidence regarding efficacy and prescription preferences of the individual SGAs is scarce.

METHODS

In the scope of this European, multi-site, naturalistic cross-sectional investigation with retrospective assessment of treatment outcome, we compared sociodemographic and clinical characteristics of 187 MDD patients receiving either quetiapine (n = 150) or aripiprazole (n = 37) as augmentation of their first-line AD psychopharmacotherapy.

RESULTS

Comorbid posttraumatic stress disorder and diabetes were significantly associated with aripiprazole augmentation in our primary and post-hoc binary logistic regression analyses. Furthermore, we identified an association between aripiprazole co-administration and the presence of additional psychotic features, higher rates of AD combination treatment, and a longer duration of psychiatric hospitalizations during the lifetime, which, however, lost significance after correcting for multiple comparisons. Regarding treatment outcome, we found a trend of higher response rates and greater reductions in severity of depressive symptoms in MDD patients dispensed quetiapine.

CONCLUSIONS

Factors associated with a more chronic and severe profile of MDD seem to encourage clinicians to choose aripiprazole over quetiapine, that was, however, administered in the majority of our MDD patients, which might reflect the current approval situation allowing to prescribe exclusively quetiapine as on-label augmentation in MDD in Europe. Given the retrospective assessment of treatment response, the markedly smaller proportion of patients receiving aripiprazole augmentation generally showing an unfavorable disease profile, and the partially heterogeneous statistical robustness of our findings, further studies are required to elaborate on our observation and to generate unambiguous recommendations regarding the choice of first-line SGA augmentation in MDD.

Ketamine and other glutamate receptor modulators for depression in adults with bipolar disorder

BACKGROUND

Glutamergic system dysfunction has been implicated in the pathophysiology of bipolar depression. This is an update of the 2015 Cochrane Review for the use of glutamate receptor modulators for depression in bipolar disorder.

OBJECTIVES

1. To assess the effects of ketamine and other glutamate receptor modulators in alleviating the acute symptoms of depression in people with bipolar disorder. 2. To review the acceptability of ketamine and other glutamate receptor modulators in people with bipolar disorder who are experiencing depressive symptoms.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Embase and PsycINFO all years to July 2020.  We did not apply any restrictions to date, language or publication status.

SELECTION CRITERIA

RCTs comparing ketamine or other glutamate receptor modulators with other active psychotropic drugs or saline placebo in adults with bipolar depression.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed trial quality and extracted data. Primary outcomes were response rate and adverse events. Secondary outcomes included remission rate, depression severity change scores, suicidality, cognition, quality of life, and dropout rate. The GRADE framework was used to assess the certainty of the evidence.

MAIN RESULTS

Ten studies (647 participants) were included in this review (an additional five studies compared to the 2015 review). There were no additional studies added to the comparisons identified in the 2015 Cochrane review on ketamine, memantine and cytidine versus placebo. However, three new comparisons were found: ketamine versus midazolam, N-acetylcysteine versus placebo, and riluzole versus placebo. The glutamate receptor modulators studied were ketamine (three trials), memantine (two), cytidine (one), N-acetylcysteine (three), and riluzole (one). Eight of these studies were placebo-controlled and two-armed. In seven trials the glutamate receptor modulators had been used as add-on drugs to mood stabilisers. Only one trial compared ketamine with an active comparator, midazolam. The treatment period ranged from a single intravenous administration (all ketamine studies), to repeated administration for riluzole, memantine, cytidine, and N-acetylcysteine (with a follow-up of eight weeks, 8 to 12 weeks, 12 weeks, and 16 to 20 weeks, respectively). Six of the studies included sites in the USA, one in Taiwan, one in Denmark, one in Australia, and in one study the location was unclear. All participants had a primary diagnosis of bipolar disorder and were experiencing an acute bipolar depressive episode, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders fourth edition (IV) or fourth edition text revision (IV-TR). Among all glutamate receptor modulators included in this review, only ketamine appeared to be more efficacious than placebo 24 hours after infusion for response rate (odds ratio (OR) 11.61, 95% confidence interval (CI) 1.25 to 107.74; P = 0.03; participants = 33; studies = 2; I² = 0%, low-certainty evidence). Ketamine seemed to be more effective in reducing depression rating scale scores (MD -11.81, 95% CI -20.01 to -3.61; P = 0.005; participants = 32; studies = 2; I² = 0%, very low-certainty evidence). There was no evidence of ketamine's efficacy in producing remission over placebo at 24 hours (OR 5.16, 95% CI 0.51 to 52.30; P = 0.72; participants = 33; studies = 2; I² = 0%, very low-certainty evidence). Evidence on response, remission or depression rating scale scores between ketamine and midazolam was uncertain at 24 hours due to very low-certainty evidence (OR 3.20, 95% CI 0.23 to 45.19). In the one trial assessing ketamine and midazolam, there were no dropouts due to adverse effects or for any reason (very low-certainty evidence). Placebo may have been more effective than N-acetylcysteine in reducing depression rating scale scores at three months, although this was based on very low-certainty evidence (MD 1.28, 95% CI 0.24 to 2.31; participants = 58; studies = 2). Very uncertain evidence found no difference in response at three months (OR 0.82, 95% CI 0.32 to 2.14; participants = 69; studies = 2; very low-certainty evidence). No data were available for remission or acceptability. Extremely limited data were available for riluzole vs placebo, finding only very-low certainty evidence of no difference in dropout rates (OR 2.00, 95% CI 0.31 to 12.84; P = 0.46; participants = 19; studies = 1; I² = 0%).

AUTHORS' CONCLUSIONS

It is difficult to draw reliable conclusions from this review due to the certainty of the evidence being low to very low, and the relatively small amount of data usable for analysis in bipolar disorder, which is considerably less than the information available for unipolar depression. Nevertheless, we found uncertain evidence in favour of a single intravenous dose of ketamine (as add-on therapy to mood stabilisers) over placebo in terms of response rate up to 24 hours, however ketamine did not show any better efficacy for remission in bipolar depression. Even though ketamine has the potential to have a rapid and transient antidepressant effect, the efficacy of a single intravenous dose may be limited. We did not find conclusive evidence on adverse events with ketamine, and there was insufficient evidence to draw meaningful conclusions for the remaining glutamate receptor modulators. However, ketamine's psychotomimetic effects (such as delusions or delirium) may have compromised study blinding in some studies, and so we cannot rule out the potential bias introduced by inadequate blinding procedures. To draw more robust conclusions, further methodologically sound RCTs (with adequate blinding) are needed to explore different modes of administration of ketamine, and to study different methods of sustaining antidepressant response, such as repeated administrations.

Study protocol for a randomised placebo-controlled trial of pramipexole in addition to mood stabilisers for patients with treatment resistant bipolar depression (the PAX-BD study)

BACKGROUND

Treatment Resistant Bipolar Depression (TRBD) is a major contributor to the burden of disease associated with Bipolar Disorder (BD). Treatment options for people experiencing bipolar depression are limited to three interventions listed by National Institute for Health and Care: lamotrigine, quetiapine and olanzapine, of which the latter two are often not well tolerated. The majority of depressed people with BD are therefore prescribed antidepressants despite limited efficacy. This demonstrates an unmet need for additional interventions. Pramipexole has been shown to improve mood symptoms in animal models of depression, in people with Parkinson's Disease and two proof of principle trials of pramipexole for people with BD who are currently depressed.

METHODS

The PAX-BD study, funded by the United Kingdom (UK) National Institute for Health Research, aims to extend previous findings by assessing the efficacy, safety and health economic impact of pramipexole in addition to mood stabilisers for patients with TRBD. A randomised, double-blind, placebo controlled design is conducted in a naturalistic UK National Health Service setting. An internal pilot study to examine feasibility and acceptability of the study design is included. Participants with TRBD are screened from National Health Service secondary care services in up to 40 mental health trusts in the UK, with the aim of recruiting approximately 414 participants into a pre-randomisation phase to achieve a target of 290 randomised participants. Primary safety and efficacy measures are at 12 weeks following randomisation, with follow up of participants to 52 weeks. The primary outcome is depressive symptoms as measured by Quick Inventory for Depressive Symptomatology - Self Report. Secondary outcomes include changes in anxiety, manic symptoms, tolerability, acceptability, quality of life and cost-effectiveness. Outcome measures are collected remotely using self-report tools implemented online, and observer-rated assessments conducted via telephone. ANCOVA will be used to examine the difference in rating scale scores between treatment arms, and dependent on compliance in completion of weekly self-report measures. A mixed effects linear regression model may also be used to account for repeated measures.

TRIAL REGISTRATION

ISRCTN72151939. Registered on 28 August 2019, http://www.isrctn.com/ISRCTN72151939 Protocol Version: 04-FEB-2021, Version 9.0.

Treatment-resistant bipolar depression: concepts and challenges for novel interventions

Treatment-resistant bipolar depression (TRBD) has been reported in about one-quarter of patients with bipolar disorders, and few interventions have shown clear and established effectiveness. We conducted a narrative review of the published medical literature to identify papers discussing treatment-resistant depression concepts and novel interventions for bipolar depression that focus on TRBD. We searched for potentially relevant English-language articles published in the last decade. Selected articles (based on the title and abstract) were retrieved for a more detailed evaluation. A number of promising new interventions, both pharmacological and non-pharmacological, are being investigated for TRBD treatment, including ketamine, lurasidone, D-cycloserine, pioglitazone, N-acetylcysteine, angiotensin-converting enzyme inhibitors, angiotensin II type 1 receptor blockers, cyclooxygenase 2 inhibitors, magnetic seizure therapy, intermittent theta-burst stimulation, deep transcranial magnetic stimulation, vagus nerve stimulation therapy, and deep brain stimulation. Although there is no consensus about the concept of TRBD, better clarification of the neurobiology associated with treatment non-response could help identify novel strategies. More research is warranted, mainly focusing on personalizing current treatments to optimize response and remission rates.

Ketamine for Bipolar Depression: A Systematic Review

BACKGROUND

Ketamine appears to have a therapeutic role in certain mental disorders, most notably unipolar major depressive disorder. However, its efficacy in bipolar depression is less clear. This study aimed to assess the efficacy and tolerability of ketamine for bipolar depression.

METHODS

We conducted a systematic review of experimental studies using ketamine for the treatment of bipolar depression. We searched PubMed, MEDLINE, Embase, PsycINFO, and the Cochrane Central Register for relevant studies published since each database's inception. We synthesized evidence regarding efficacy (improvement in depression rating scores) and tolerability (adverse events, dissociation, dropouts) across studies.

RESULTS

We identified 6 studies, with 135 participants (53% female; 44.7 years; standard deviation, 11.7 years). All studies used 0.5 mg/kg of add-on intravenous racemic ketamine, with the number of doses ranging from 1 to 6; all participants continued a mood-stabilizing agent. The overall proportion achieving a response (defined as those having a reduction in their baseline depression severity of at least 50%) was 61% for those receiving ketamine and 5% for those receiving a placebo. The overall response rates varied from 52% to 80% across studies. Ketamine was reasonably well tolerated; however, 2 participants (1 receiving ketamine and 1 receiving placebo) developed manic symptoms. Some participants developed significant dissociative symptoms at the 40-minute mark following ketamine infusion in 2 trials.

CONCLUSIONS

There is some preliminary evidence supporting use of intravenous racemic ketamine to treat adults with bipolar depression. There is a need for additional studies exploring longer-term outcomes and alterative formulations of ketamine.

Comparison of hypothalamo-pituitary-adrenal function in treatment resistant unipolar and bipolar depression

Altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis has been demonstrated in patients with treatment-resistant depression, although studies have often conflated patients with unipolar and bipolar depression. This is problematic given that the two groups often present with opposed neurovegetative symptom patterns. The aim of this study was to test, for the first time, whether post-awakening cortisol, a highly reliable, naturalistic measure of HPA functioning, could distinguish patients with clearly defined treatment-resistant unipolar (TRUD) and bipolar depression (TRBD). A total of 37 patients with TRUD, 17 patients with TRBD, and 47 healthy controls were recruited. Areas under the curve (AUC) with respect to the ground (g) and increase (i) of post-awakening cortisol concentrations (awakening, +15, +30, +45, +60, +90 min) were measured over two days. Patients with TRUD had higher total cortisol production in the morning hours compared to controls (AUCg, p = 0.01), while they did not differ in terms of the awakening response (AUCi, p = 0.28). By contrast, subjects with TRBD had lower total cortisol when compared to controls by trend (AUCg, p = 0.07), while they did not differ in the awakening response (AUCi, p = 0.15). A direct comparison of TRUD and TRBD revealed differences in the AUCg (p = 0.003) and AUCi (p = 0.03). This finding of comparatively elevated HPA axis activity in the morning in TRUD and attenuated HPA axis activity in TRBD attests to a fundamental biological distinction between unipolar and bipolar depression. It has implications for the understanding and treatment of bipolar depression and in differentiating the two types of depression.

Inflammation-driven brain and gut barrier dysfunction in stress and mood disorders

Regulation of emotions is generally associated exclusively with the brain. However, there is evidence that peripheral systems are also involved in mood, stress vulnerability vs. resilience, and emotion‐related memory encoding. Prevalence of stress and mood disorders such as major depression, bipolar disorder, and post‐traumatic stress disorder is increasing in our modern societies. Unfortunately, 30%–50% of individuals respond poorly to currently available treatments highlighting the need to further investigate emotion‐related biology to gain mechanistic insights that could lead to innovative therapies. Here, we provide an overview of inflammation‐related mechanisms involved in mood regulation and stress responses discovered using animal models. If clinical studies are available, we discuss translational value of these findings including limitations. Neuroimmune mechanisms of depression and maladaptive stress responses have been receiving increasing attention, and thus, the first part is centered on inflammation and dysregulation of brain and circulating cytokines in stress and mood disorders. Next, recent studies supporting a role for inflammation‐driven leakiness of the blood–brain and gut barriers in emotion regulation and mood are highlighted. Stress‐induced exacerbated inflammation fragilizes these barriers which become hyperpermeable through loss of integrity and altered biology. At the gut level, this could be associated with dysbiosis, an imbalance in microbial communities, and alteration of the gut–brain axis which is central to production of mood‐related neurotransmitter serotonin. Novel therapeutic approaches such as anti‐inflammatory drugs, the fast‐acting antidepressant ketamine, and probiotics could directly act on the mechanisms described here improving mood disorder‐associated symptomatology. Discovery of biomarkers has been a challenging quest in psychiatry, and we end by listing promising targets worth further investigation.

Case Report: Repeated Transcranial Magnetic Stimulation Improves Comorbid Binge Eating Disorder in Two Female Patients With Treatment-Resistant Bipolar Depression

Introduction: Binge eating disorder (BED) is the most common eating disorder, affecting a large population worldwide. It is characterized by recurrent episodes of binge eating, with no compensatory behaviors. BED is often associated with psychiatric comorbidities, and still represents a challenge in terms of treatment strategies. In the last years, neuromodulation has represented a promising approach in the treatment of BED. We report the cases of two women, affected by Bipolar Disorder Type II (BD-II) and comorbid BED, whose BED symptoms improved after a course of accelerated intermittent Theta Burst Stimulation (iTBS). Methods: We carried out a clinical study, involving neurostimulation on six patients with a treatment-resistant depressive episode. The trial consisted of a 3-week accelerated iTBS treatment, delivered to the left dorsolateral pre-frontal cortex. Clinical evaluation scales (Hamilton Rating Scale for Depression, Montgomery-Åsberg Depression Rating Scale, and Young Mania Rating Scale) were administered at baseline, after 2 weeks, and at the end of the stimulation cycle. Pharmacotherapy was maintained unchanged during iTBS treatment. Patients gave their informed consent both for the protocol and for the publication. Results: The treatment was well-tolerated. Depressive symptoms only slightly improved; however, patients' binge episodes remitted completely, which was a serendipitous finding. BED symptomatology complete remission lasted up to 12 weeks follow-up. Discussion: This is the first study regarding iTBS use in BED in comorbidity with BD-II. Further research is still needed to assess the efficacy of this technique in BED treatment.

Bipolar disorders

Bipolar disorders are a complex group of severe and chronic disorders that includes bipolar I disorder, defined by the presence of a syndromal, manic episode, and bipolar II disorder, defined by the presence of a syndromal, hypomanic episode and a major depressive episode. Bipolar disorders substantially reduce psychosocial functioning and are associated with a loss of approximately 10-20 potential years of life. The mortality gap between populations with bipolar disorders and the general population is principally a result of excess deaths from cardiovascular disease and suicide. Bipolar disorder has a high heritability (approximately 70%). Bipolar disorders share genetic risk alleles with other mental and medical disorders. Bipolar I has a closer genetic association with schizophrenia relative to bipolar II, which has a closer genetic association with major depressive disorder. Although the pathogenesis of bipolar disorders is unknown, implicated processes include disturbances in neuronal-glial plasticity, monoaminergic signalling, inflammatory homoeostasis, cellular metabolic pathways, and mitochondrial function. The high prevalence of childhood maltreatment in people with bipolar disorders and the association between childhood maltreatment and a more complex presentation of bipolar disorder (eg, one including suicidality) highlight the role of adverse environmental exposures on the presentation of bipolar disorders. Although mania defines bipolar I disorder, depressive episodes and symptoms dominate the longitudinal course of, and disproportionately account for morbidity and mortality in, bipolar disorders. Lithium is the gold standard mood-stabilising agent for the treatment of people with bipolar disorders, and has antimanic, antidepressant, and anti-suicide effects. Although antipsychotics are effective in treating mania, few antipsychotics have proven to be effective in bipolar depression. Divalproex and carbamazepine are effective in the treatment of acute mania and lamotrigine is effective at treating and preventing bipolar depression. Antidepressants are widely prescribed for bipolar disorders despite a paucity of compelling evidence for their short-term or long-term efficacy. Moreover, antidepressant prescription in bipolar disorder is associated, in many cases, with mood destabilisation, especially during maintenance treatment. Unfortunately, effective pharmacological treatments for bipolar disorders are not universally available, particularly in low-income and middle-income countries. Targeting medical and psychiatric comorbidity, integrating adjunctive psychosocial treatments, and involving caregivers have been shown to improve health outcomes for people with bipolar disorders. The aim of this Seminar, which is intended mainly for primary care physicians, is to provide an overview of diagnostic, pathogenetic, and treatment considerations in bipolar disorders. Towards the foregoing aim, we review and synthesise evidence on the epidemiology, mechanisms, screening, and treatment of bipolar disorders.

The concept and management of acute episodes of treatment-resistant bipolar disorder: a systematic review and exploratory meta-analysis of randomized controlled trials

BACKGROUND

The definitions of treatment-resistant bipolar disorder (TRBD) have varied across studies. Additionally, its management is clinically challenging. An updated synthesis and appraisal of the available evidence is needed.

METHODS

A systematic search of major electronic databases from inception up to May 25th, 2020, was conducted to identify randomized controlled trials (RCTs) of pharmacological and non-pharmacological interventions for the management of TRBD. When sufficient evidence was available, a meta-analysis was conducted.

RESULTS

Seventeen studies (n = 928 patients) were included in the qualitative synthesis. Fourteen studies (n = 803) assessed treatment-resistant acute bipolar depression (TRBD-De), including five neuromodulatory and nine pharmacological trials. Rapid- vs. standard up-titration of clozapine showed promising efficacy for TRBD mania, without significant adverse events. Electroconvulsive therapy (ECT) was confirmed to be similarly effective for TRBD-De as for treatment-resistant unipolar depression: odd ratio, OR = 0.919 (95%C.I. = 0.44-1.917), I² = 13.98, p = .822. TRBD-De patients exposed to ketamine at day one post-infusion had high odds of response: OR = 10.682 (95%C.I. = 2.142-53.272), I² = 0, p = <.005. The pooled drop-out rate in the ketamine trials was 21.2%. Additional evidence is warranted to confirm the potential efficacy of pramipexole or stimulants for TRBD-De.

LIMITATIONS

Publication/measurement bias; exploratory nature of the meta-analyses for interventions that included participants solely with TRBD-De.

CONCLUSIONS

Overall, a few interventions are available for TRBD, including pramipexole, ECT, and clozapine, among others. Larger and better-designed trials for TRBD are warranted and should be based on more uniform operational definitions. PROSPERO registration number: CRD42018114567.

Transient effects of multi-infusion ketamine augmentation on treatment-resistant depressive symptoms in patients with treatment-resistant bipolar depression - An open-label three-week pilot study

INTRODUCTION

While the psychiatric benefits of ketamine have been verified through clinical trials, there is limited information about ketamine augmentation in patients with treatment-resistant bipolar depression (TRBPD). Hence, in the present study, we investigate the therapeutic efficacy and functional brain alterations associated with multi-infusion ketamine augmentation in patients with TRBPD.

METHODS

The present three-week study included 38 patients with TRBPD, all of whom received a series of nine ketamine injections over the study period. The Hamilton Depression Rating Scale (HAMD) was used to assess the effects of multi-infusion ketamine combined with mood stabilizers. Brain function was evaluated by global functional connectivity density (gFCD).

RESULTS

Adjunctive treatment with multiple infusions of ketamine, when combined with a mood stabilizer, could effectively alleviate depressive symptoms for one week, yet the symptoms began to relapse during the second week. Functional brain alterations were detected via gFCD. Specifically, gFCD reductions were mainly found in the bilateral insula, right caudate nucleus, and bilateral inferior frontal gyrus, while increased gFCD was mainly located in the bilateral postcentral gyrus, subgenual anterior cingulate cortex, bilateral thalamus, and cerebellum. Although gFCD alterations were sustained for up to three weeks after the first ketamine infusion, the antidepressant effects of ketamine augmentation sharply declined from the end of the second week of treatment.

CONCLUSIONS

Multi-infusion ketamine augmentation can rapidly alleviate depressive symptoms in patients with TRBPD. The clinical effects were primarily visible in the first week after treatment and partially sustained for two weeks; however, the therapeutic effects and related functional brain alterations sharply decreased from the end of the second week. Based on these findings, we demonstrated that the clinical efficacy and functional brain alterations induced by ketamine augmentation are transient.

Effects of adjunctive inflammatory modulation on IL-1β in treatment resistant bipolar depression

BACKGROUND

Adjunctive inflammatory modulation improved remission rates in treatment-resistant bipolar depression (TRBDD), but reliable biomarkers must be established to characterize the biosignature of TRBDD and the mechanisms underlying treatment response. In this molecular profiling study, we describe TRBDD and treatment response from the standpoint of interleukin-1 Beta (IL-1β) and KYN/TRP.

METHODS

47 TRBDD patients with moderately severe HAMD-17 scores were randomized to receive either escitalopram (ESC) (10 mg-40 mg daily dose range) + celecoxib (CBX) (200 mg twice daily), or ESC (10 mg-40 mg daily dose range) + placebo (PBO) (twice daily). Plasma cytokine levels were measured in both treatment arms at baseline and week 8, and in a healthy control (HC) group of subjects (N = 43) once. A linear mixed model (LMM) was applied to evaluate whether clinical outcome is related to CBX and changes to biomarkers throughout treatment. A binary logistic regression model was formulated from this series to predict both the primary outcome of treatment response to CBX, and the secondary outcome of diagnosis of TRBDD using age, BMI, gender, and IL-1β at baseline.

RESULTS

Patients receiving ESC + CBX had 4.278 greater odds of responding (p = 0.021) with NNT = 3, and 15.300 times more likely to remit (p < 0.001) with NNT = 2, compared with ESC + PBO patients. Patient BMI (p = 0.003), baseline IL-1β (p = 0.004), and baseline KYN/TRP (p = 0.001) were most predictive of TRBDD diagnosis. By Week 8, responders showed a downtrend in IL-1β compared to non-responders in the ESC + CBX treatment arm. However, there was no statistical difference in the IL-1β or KYN/TRP change after treatment between placebo and ESC + CBX group responders/non-responders (p = 0.239, and p = 0.146, respectively). While baseline IL-1β was elevated in TRBDD compared to HC (p < 0.001), there was no difference in IL-1β between treatment responders at Week 8 compared to HC (p = 0.067).

CONCLUSIONS

Elevated IL-1β and low KYN/TRP at baseline are components of the TRBDD molecular signature. CBX but not baseline IL-1β or KYN/TRP predict treatment response. Change in IL-1β and KYN/TRP did not predict treatment response.

The effects of vagus nerve stimulation on the course and outcomes of patients with bipolar disorder in a treatment-resistant depressive episode: a 5-year prospective registry

BACKGROUND

To compare illness characteristics, treatment history, response and durability, and suicidality scores over a 5-year period in patients with treatment-resistant bipolar depression participating in a prospective, multicenter, open-label registry and receiving Vagus Nerve Stimulation Therapy (VNS Therapy) plus treatment-as-usual (VNS + TAU) or TAU alone.

METHODS

Response was defined as ≥ 50% decrease from baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total score at 3, 6, 9, or 12 months post-baseline. Response was retained while MADRS score remained ≥ 40% lower than baseline. Time-to-events was estimated using Kaplan-Meier (KM) analysis and compared using log-rank test. Suicidality was assessed using the MADRS Item 10 score.

RESULTS

At baseline (entry into registry), the VNS + TAU group (N = 97) had more episodes of depression, psychiatric hospitalizations, lifetime suicide attempts and higher suicidality score, more severe symptoms (based on MADRS and other scales), and higher rate of prior electroconvulsive therapy than TAU group (N = 59). Lifetime use of medications was similar between the groups (a mean of 9) and was consistent with the severe treatment-resistant nature of their depression. Over 5 years, 63% (61/97) in VNS + TAU had an initial response compared with 39% (23/59) in TAU. The time-to-initial response was significantly quicker for VNS + TAU than for TAU (p < 0.03). Among responders in the first year after implant, the KM estimate of the median time-to-relapse from initial response was 15.2 vs 7.6 months for VNS + TAU compared with TAU (difference was not statistically significant). The mean reduction in suicidality score across the study visits was significantly greater in the VNS + TAU than in the TAU group (p < 0.001).

CONCLUSIONS

The patients who received VNS + TAU included in this analysis had severe bipolar depression that had proved extremely difficult to treat. The TAU comparator group were similar though had slightly less severe illnesses on some measures and had less history of suicide attempts. Treatment with VNS + TAU was associated with a higher likelihood of attaining a response compared to TAU alone. VNS + TAU was also associated with a significantly greater mean reduction in suicidality.

LIMITATIONS

In this registry study, participants were not randomized to the study treatment group, VNS Therapy stimulation parameters were not controlled, and there was a high attrition rate over 5 years. Trial registration ClinicalTrials.gov NCT00320372. Registered 3 May 2006, https://clinicaltrials.gov/ct2/show/NCT00320372 (retrospectively registered).

The CINP Guidelines on the Definition and Evidence-Based Interventions for Treatment-Resistant Bipolar Disorder

BACKGROUND

Resistant bipolar disorder is a major mental health problem related to significant disability and overall cost. The aim of the current study was to perform a systematic review of the literature concerning (1) the definition of treatment resistance in bipolar disorder, (2) its clinical and (3) neurobiological correlates, and (4) the evidence-based treatment options for treatment-resistant bipolar disorder and for eventually developing guidelines for the treatment of this condition.

MATERIALS AND METHODS

The PRISMA method was used to identify all published papers relevant to the definition of treatment resistance in bipolar disorder and the associated evidence-based treatment options. The MEDLINE was searched to April 22, 2018.

RESULTS

Criteria were developed for the identification of resistance in bipolar disorder concerning all phases. The search of the literature identified all published studies concerning treatment options. The data were classified according to strength, and separate guidelines regarding resistant acute mania, acute bipolar depression, and the maintenance phase were developed.

DISCUSSION

The definition of resistance in bipolar disorder is by itself difficult due to the complexity of the clinical picture, course, and treatment options. The current guidelines are the first, to our knowledge, developed specifically for the treatment of resistant bipolar disorder patients, and they also include an operationalized definition of treatment resistance. They were based on a thorough and deep search of the literature and utilize as much as possible an evidence-based approach.

Specialist physician perspectives on non-medical switching of prescription medications

Introduction: A non-medical switch is a change to a patient's medication regimen for reasons other than lack of clinical response, side-effects or poor adherence. Specialist physicians treat complex patients who may be vulnerable to non-medical switching. Objectives: To evaluate specialist physicians' perceptions regarding the frequency of non-medical switch requests, and the impact on their patients' outcomes and healthcare utilization. Methods: An online survey of randomly sampled physicians spending ≥10% of time providing patient care and having received ≥1 non-medical switch request during the prior 12-months. Results: Among 404 specialist physicians surveyed, non-medical switch requests were reported as very frequent or frequent by 35.0% of oncologists (for injectable cancer agents) and up to 80.3% of endocrinologists (for injectable anti-hyperglycemics). Respondents reported decreased medication effectiveness (25.0% of oncologists to 75.0% of dermatologists) and increased side-effects (32.5% of oncologists to 66.7% of psychiatrists). Most specialists reported very frequent or frequent increases in non-office visits (52.5% of oncologists to 75.3% of endocrinologists) and calls with pharmacies (57.5% of oncologists to 80.5% of rheumatologists) due to non-medical switching. Conclusions: Receipt of non-medical switching requests were common among specialist physicians. Non-medical switching may lead to negative effects on patient care and require increased healthcare utilization.

Defining treatment-resistant depression

BACKGROUND

Varying conceptualizations of treatment-resistant depression (TRD) have made translating research findings or systematic reviews into clinical practice guidelines challenging and inconsistent.

METHODS

We conducted a review for the Centers for Medicare & Medicaid Services and the Agency for Healthcare Research and Quality to clarify how experts and investigators have defined TRD and to review systematically how well this definition comports with TRD definitions in clinical trials through July 5, 2019.

RESULTS

We found that no consensus definition existed for TRD. The most common TRD definition for major depressive disorder required a minimum of two prior treatment failures and confirmation of prior adequate dose and duration. The most common TRD definition for bipolar disorder required one prior treatment failure. No clear consensus emerged on defining adequacy of either dose or duration. Our systematic review found that only 17% of intervention studies enrolled samples meeting the most frequently specified criteria for TRD. Depressive outcomes and clinical global impressions were commonly measured; functional impairment and quality-of-life tools were rarely used.

CONCLUSIONS

Two key steps are critical to advancing TRD research: (a) Developing a consensus definition of TRD that addresses how best to specify the number of prior treatment failures and the adequacy of dose and duration; and (b) identifying a core package of outcome measures that can be applied in a standardized manner. Our recommendations about stronger approaches to designing and conducting TRD research will foster better evidence to translate into clearer guidelines for treating patients with this serious condition.

Modulation of the inflammatory response benefits treatment-resistant bipolar depression: A randomized clinical trial

OBJECTIVE

The goal of this study was to reduce treatment resistance and enhance antidepressant response in patients with treatment-resistant bipolar depression (TRBDD) by modulating inflammatory activation.

METHODS

Forty-seven TRBDD patients completed a randomized, double-blind, placebo (PBO)-controlled two-arm study using celecoxib (CBX), a cyclooxygenase 2 (COX-2) inhibitor, in combination with escitalopram (ESC). The Hamilton Depression (17-Item) and the Hamilton Anxiety Rating Scales were used to quantify symptom severity. Self-rating instruments included BDI, BAI and QLES-Q questioner. An adverse events inventory was used, and the possibility of bleeding diathesis was monitored. Complete blood count (CBC), prothrombin time (PT), and activated partial thromboplastin time (APTT) were determined. Comparison of mood scores between the CBX and PBO groups were conducted using a mixed ANOVA and an Independent Sample Student t-test.

RESULTS

The CBX adjunctive treatment produced significantly more responders and remitters than the PBO arm. Compared to the PBO group (n = 20), the CBX group (n = 27) experienced lower depression severity through the entire course of the study, showing significant decrease in depression and anxiety scores as early as week 1. Except for initial mild nausea, no adverse events were reported and study medications were well tolerated.

CONCLUSIONS

Modulation of the inflammatory response through targeted inhibition of the enzyme COX-2 by means of CBX reduces TRBDD and augments and accelerates treatment response in an efficacious and safe manner. Future studies should replicate these findings and additionally investigate whether prolonged administration of CBX is required to maintain remission by adding a discontinuation phase to the study design.

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT01479829.

Predictors of Treatment Resistance Across Different Clinical Subtypes of Depression: Comparison of Unipolar vs. Bipolar Cases

OBJECTIVE

Treatment-resistant depression (TRD) and treatment-resistant bipolar depression (TRBD) poses a significant clinical and societal burden, relying on different operational definitions and treatment approaches. The detection of clinical predictors of resistance is elusive, soliciting clinical subtyping of the depressive episodes, which represents the goal of the present study.

METHODS

A hundred and thirty-one depressed outpatients underwent psychopathological evaluation using major rating tools, including the Hamilton Rating Scale for Depression, which served for subsequent principal component analysis, followed-up by cluster analysis, with the ultimate goal to fetch different clinical subtypes of depression.

RESULTS

The cluster analysis identified two clinically interpretable, yet distinctive, groups among 53 bipolar (resistant cases = 15, or 28.3%) and 78 unipolar (resistant cases = 20, or 25.6%) patients. Among the MDD patients, cluster "1" included the following components: "Psychic symptoms, depressed mood, suicide, guilty, insomnia" and "genitourinary, gastrointestinal, weight loss, insight". Altogether, with broadly defined "mixed features," this latter cluster correctly predicted treatment outcome in 80.8% cases of MDD. The same "broadly-defined" mixed features of depression (namely, the standard Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition-DSM-5-specifier plus increased energy, psychomotor activity, irritability) correctly classified 71.7% of BD cases, either as TRBD or not.

LIMITATIONS

Small sample size and high rate of comorbidity.

CONCLUSIONS

Although relying on different operational criteria and treatment history, TRD and TRBD seem to be consistently predicted by broadly defined mixed features among different clinical subtypes of depression, either unipolar or bipolar cases. If replicated by upcoming studies to encompass also biological and neuropsychological measures, the present study may aid in precision medicine and informed pharmacotherapy.

Ketamine in Bipolar Disorder: A Review

Bipolar disorder (BD) is a psychiatric illness associated with high morbidity, mortality and suicide rate. It has neuroprogressive course and a high rate of treatment resistance. Hence, there is an unquestionable need for new BD treatment strategies. Ketamine appears to have rapid antidepressive and antisuicidal effects. Since most of the available studies concern unipolar depression, here we present a novel insight arguing that ketamine might be a promising treatment for bipolar disorder.

The Impact of Subsyndromal Bipolar Symptoms on Patient's Functionality and Quality of Life

Subsyndromal symptoms have rarely been in the focus of bipolar research. This may be, in part, due to the fact that there is neither a uniform definition nor do they constitute an indication of regulatory and commercial interest. Nevertheless, they do have a decisive impact on the long-term course of bipolar disorder (BD), and the degree of functionality and quality of life (QoL) is more likely determined by their presence or absence than by acute episodes. Summarizing the literature an estimated 20-50% of patients suffer inter-episodically or chronically from subsyndromal BD. The most prominent symptoms that interfere with functionality are subsyndromal depression, disturbances of sleep, and perceived cognitive impairment, whereas anxiety negatively impacts on QoL. In the absence of evidence-based pharmacological treatments for subsyndromal BD, clinical practice adopts guidelines designed for treatment-resistant full-blown episodes of BD, supplemented by cognitive-behavioral, family focused or social-rhythm-based psychotherapies.

Group Cognitive Behavioral Analysis System of Psychotherapy (CBASP): A Pilot Study for Bipolar Depression

OBJECTIVES

Cognitive Behavioral Analysis System of Psychotherapy (CBASP) is an individually administered treatment model designed specifically for Persistent Depression however bipolar patients have traditionally been excluded from CBASP studies. There is a perception that bipolar depression will be harder to treat and requires a unique psychological approach. This pilot study reports on the feasibility of administering the same 20-week manualized group CBASP therapy with bipolar patients currently in a depressive episode.

METHODS

This non-randomized, single-arm prospective pilot study, reports on an a posteriori exploration of benefits to bipolar depressed patients (n=26) of the same 20-week group CBASP intervention administered to unipolar depressed patients (n=81). The clinical trial for the initial phase examining benefits of the manualized 20-week group CBASP intervention with unipolar patients was registered with the ISRCTN registry, study ID: ISRCTN95149444. Results reported here include mixed ANOVA analyses, across group treatment models and diagnostic categories. Changes over time in self-reported depressive symptoms (Inventory of Depressive Symptoms -IDS-SR), self-reported social functioning, interpersonal problems and interpersonal dispositions are documented for all patients. An exploratory longitudinal latent class analysis was used to examine patients' trajectories of improvement in depressive symptoms. Finally, the best predictors of change in reported depressive symptoms were explored with a logistic regression for all patients.

RESULTS

Improvements in depressive symptoms and in social functioning over time were significant for all patients with bipolar patients trending towards a greater improvement in depressive symptoms after controlling for baseline differences. An exploratory Latent Class Analysis identified two different treatment trajectories for the entire sample: 1) moderate to severely depressed patients who improved significantly (49%) and 2) severely depressed patients who did not improve (51%). The best predictors of non-response to group therapy include high baseline problems in social functioning and low rates of self-reported Perceived Improvements in overall health.

CONCLUSION

Bipolar patients in a depressive episode appear to benefit from the same 20-week group CBASP model designed originally for the treatment of Persistent Depressive Disorder. Bipolar patients seem more easily mobilized both during and outside of group therapy sessions and report more interpersonal confidence and more agency than unipolar depressed patients.

Effects of Exercise on Long-Term Potentiation in Neuropsychiatric Disorders

Various neuropsychiatric conditions, such as depression, Alzheimer's disease, and Parkinson's disease, demonstrate evidence of impaired long-term potentiation, a cellular correlate of episodic memory function. This chapter discusses the mechanistic effects of these neuropsychiatric conditions on long-term potentiation and how exercise may help to attenuate these detrimental effects.

Rapid-acting antidepressant ketamine, its metabolites and other candidates: A historical overview and future perspective

Major depressive disorder (MDD) is one of the most disabling psychiatric disorders. Approximately one-third of the patients with MDD are treatment resistant to the current antidepressants. There is also a significant therapeutic time lag of weeks to months. Furthermore, depression in patients with bipolar disorder (BD) is typically poorly responsive to antidepressants. Therefore, there exists an unmet medical need for rapidly acting antidepressants with beneficial effects in treatment-resistant patients with MDD or BD. Accumulating evidence suggests that the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine produces rapid and sustained antidepressant effects in treatment-resistant patients with MDD or BD. Ketamine is a racemic mixture comprising equal parts of (R)-ketamine (or arketamine) and (S)-ketamine (or esketamine). Because (S)-ketamine has higher affinity for NMDAR than (R)-ketamine, esketamine was developed as an antidepressant. On 5 March 2019, esketamine nasal spray was approved by the US Food and Drug Administration. However, preclinical data suggest that (R)-ketamine exerts greater potency and longer-lasting antidepressant effects than (S)-ketamine in animal models of depression and that (R)-ketamine has less detrimental side-effects than (R,S)-ketamine or (S)-ketamine. In this article, the author reviews the historical overview of the antidepressant actions of enantiomers of ketamine and its major metabolites norketamine and hydroxynorketamine. Furthermore, the author discusses the other potential rapid-acting antidepressant candidates (i.e., NMDAR antagonists and modulators, low-voltage-sensitive T-type calcium channel inhibitor, potassium channel Kir4.1 inhibitor, negative modulators of γ-aminobutyric acid, and type A [GABA_A ] receptors) to compare them with ketamine. Moreover, the molecular and cellular mechanisms of ketamine's antidepressant effects are discussed.

Results of the European Group for the Study of Resistant Depression (GSRD) - basis for further research and clinical practice

Objectives: The overview outlines two decades of research from the European Group for the Study of Resistant Depression (GSRD) that fundamentally impacted evidence-based algorithms for diagnostics and psychopharmacotherapy of treatment-resistant depression (TRD). Methods: The GSRD staging model characterising response, non-response and resistance to antidepressant (AD) treatment was applied to 2762 patients in eight European countries. Results: In case of non-response, dose escalation and switching between different AD classes did not show superiority over continuation of original AD treatment. Predictors for TRD were symptom severity, duration of the current major depressive episode (MDE), suicidality, psychotic and melancholic features, comorbid anxiety and personality disorders, add-on treatment, non-response to the first AD, adverse effects, high occupational level, recurrent disease course, previous hospitalisations, positive family history of MDD, early age of onset and novel associations of single nucleoid polymorphisms (SNPs) within the PPP3CC, ST8SIA2, CHL1, GAP43 and ITGB3 genes and gene pathways associated with neuroplasticity, intracellular signalling and chromatin silencing. A prediction model reaching accuracy of above 0.7 highlighted symptom severity, suicidality, comorbid anxiety and lifetime MDEs as the most informative predictors for TRD. Applying machine-learning algorithms, a signature of three SNPs of the BDNF, PPP3CC and HTR2A genes and lacking melancholia predicted treatment response. Conclusions: The GSRD findings offer a unique and balanced perspective on TRD representing foundation for further research elaborating on specific clinical and genetic hypotheses and treatment strategies within appropriate study-designs, especially interaction-based models and randomized controlled trials.