Tachyphylaxis in major depressive disorder: A review of the current state of research

Longitudinal Influence of Prescribed Antidepressants on Fecal and Oral Microbiomes Among Veterans With Major Depressive Disorder

OBJECTIVE

The purpose of this study was to evaluate the influence of a new course of antidepressant monotherapy on gut and oral microbiomes and the relationship to depressive symptoms.

METHODS

Longitudinal microbiome samples obtained from 10 U.S. veterans were analyzed. Baseline samples were taken before a new course of antidepressant monotherapy (either switching from a previous treatment or starting a new treatment). Targeted genomic sequencing of the microbiome samples was used to analyze changes in taxonomy and diversity across participants, medications, and medication class. Associations between these changes and Patient Health Questionnaire-9 (PHQ-9) scores were analyzed.

RESULTS

Taxonomic variability was observed across participants, with the individual being the main microbial community driver. In terms of the fecal microbiome, antidepressants were associated with shifts toward Bacteroides being less abundant and Blautia, Pseudomonas, or Faecalibacterium being more abundant. Likewise, the composition of the oral microbiome was variable, with individual participants being the primary drivers of community composition. In the oral samples, the relative abundance of Haemophilus decreased after antidepressants were started. Increases in Blautia and decreases in Bacteroides were associated with lower PHQ-9 scores.

CONCLUSIONS

Antidepressants were found to influence fecal and oral microbiomes such that a new course of antidepressant monotherapy was associated with taxonomic alterations toward healthier states in both fecal and oral microbiomes, which were associated with decreases in depressive symptoms. Additional longitudinal research is required to increase understanding of microbiomes and symptom-based changes, with a particular focus on potential differences between medication classes and underlying mechanisms.

The correlation of Esketamine with specific adverse events: a deep dive into the FAERS database

Analyzing the vast data from FAERS database to evaluate the association between Esketamine and specific adverse events to guide clinical practice and regulatory decisions. Data related to Esketamine adverse events from 2019 Q1 to 2023 Q1 were collected from FAERS database. After data standardization, various signal quantification technologies, such as ROR, PRR, BCPNN, and MGPS, were employed to identify and evaluate adverse reaction signals closely related to the use of Esketamine comprehensively. A total of 5061 reports with Esketamine as the primary suspected drug were obtained, identifying 117 adverse reaction terms (PT) involving 27 system organ class (SOC) categories. Apart from the adverse events already mentioned in the drug's instructions, this study identified some new, clinically valuable potential AE signals, such as Flashback, Tachyphylaxis, and Autoscopy. In addition, high-ranking results included euphoric mood, feeling of relaxation, and feeling drunk. Notably, the occurrence frequencies of suicidal ideation and suicide attempt were relatively high, so clinicians should be particularly vigilant about these potential adverse reactions when using Esketamine. Moreover, since this drug is administered as a nasal spray, issues such as drug monitoring procedure incorrectly performed and nasal discomfort may arise. This study underscores the potential adverse reactions and risks of Esketamine in clinical applications, especially regarding long-term efficacy, addiction risks, and suicidal risks.

Treating depression in clinical practice: new insights on the multidisciplinary use of trazodone

Depression is estimated to be a leading contributor to the global mental health-related burden. The determinants of this huge prevalence lie in the fact that depressive symptoms may be comorbid in a wide variety of disorders, thus complicating and exacerbating their clinical framework. This makes the treatment of depressive symptoms difficult, since many pharmacological interactions should be considered by physicians planning therapy. Hence, depression still represents a challenge for both psychiatrists and other clinicians, in terms of its high rates of relapse and resistance despite well-established protocols. It is also complicated by the well-known latency in its complete response to current antidepressant treatments. In this context, the search for new strategies regarding antidepressant treatment is mandatory. Revising the use of "old" pharmacotherapies by considering their specific features may help to perfecting the treatment of depression, both in its standalone psychiatric manifestation and in the framework of other clinical conditions. Using a nominal group technique approach, the results of a consensus of expert physicians regarding the possible use of trazodone as a valuable strategy for addressing the "real world" unmet needs of depression treatment in different fields (psychiatry, primary care, neurology and geriatrics) is herein provided. This idea is based on the unique characteristics of this drug which delivers a more rapid antidepressant action as compared to other selective serotonin reuptake inhibitors. It also has pharmacodynamic malleability (i.e., the possibility of exerting different effects on depressive symptoms at different dosages) and pharmacokinetic tolerability (i.e., the possibility of being used as an add-on to other antidepressants with scarce interaction and achieving complimentary effects) when used in the milieu of other drugs in treating comorbid depressive symptoms. Moreover, the large number of formulations available permits finite dosage adjustments, and the use of trazodone for specific pathologies, such as dysphagia. Therefore, although additional studies exploring the real-world conditions of antidepressant treatment are warranted, experts agree on the idea that depressive disorder, in both its standalone and its comorbid manifestations, may surely take advantage of the particular characteristics of trazodone, thus attempting to reach the greatest effectiveness in different contexts.

Esketamine vs Midazolam in Boosting the Efficacy of Oral Antidepressants for Major Depressive Disorder: A Pilot Randomized Clinical Trial

Importance

Loss of a previously effective response while still using adequate antidepressant treatment occurs in a relatively high proportion of patients with major depressive disorder (MDD); therefore, there is a need to develop novel effective treatment strategies.

Objective

To assess the efficacy and safety of a single subanesthetic dose of esketamine in boosting the efficacy of oral antidepressants for treating fluctuating antidepressant response in MDD.

Design, Setting, and Participants

This single-center, double-blind, midazolam-controlled pilot randomized clinical trial was conducted at Beijing Anding Hospital, Capital Medical University in China. The study enrolled participants aged 18 years and older with fluctuating antidepressant response, defined as patients with MDD experiencing fluctuating symptoms after symptom relief and stabilization. Patient recruitment was conducted from August 2021 to January 2022, and participants were followed-up for 6 weeks. Data were analyzed as intention-to-treat from July to September 2022.

Interventions

All participants in the esketamine-treated group received intravenous esketamine at 0.2 mg/kg in 40 minutes. Participants in the midazolam control group received intravenous midazolam at 0.045 mg/kg in 40 minutes.

Main Outcomes and Measures

The primary outcome was the response rate at 2 weeks, defined as a 50% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS). Secondary outcomes included response rate at 6 weeks, remission rates at 2 and 6 weeks, and change in MADRS and Clinical Global Impression-Severity score from baseline to 6 weeks; remission was defined by a MADRS score of 10 or lower.

Results

A total of 30 patients (median [IQR] age, 28.0 [24.0-40.0] years; 17 [56.7%] female) were randomized, including 15 patients randomized to midazolam and 15 patients randomized to esketamine; 29 patients completed the study. Response rates at 2 weeks were significantly higher in the esketamine-treated group than in the midazolam control group (10 patients [66.7%] vs 1 patient [6.7%]; P < .001). Participants treated with esketamine experienced significantly greater reduction in MADRS score from baseline to 2 weeks compared with those treated with midazolam (mean [SD] reduction, 15.7 [1.5] vs 3.1 [1.3]; P < .001). No serious adverse events were observed in this trial, and no psychotogenic effects and clinically significant manic symptoms were reported.

Conclusions and Relevance

This pilot randomized clinical trial found that a single subanesthetic dose of esketamine could boost the efficacy of oral antidepressants in treating fluctuating antidepressant response, with a good safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2100050335.

Considerations when selecting an antidepressant: a narrative review for primary care providers treating adults with depression

Major depressive disorder (MDD) is a debilitating mental disorder that can be treated with a number of different antidepressant therapies, each with its own unique prescribing considerations. Complicating the selection of an appropriate antidepressant for adults with MDD is the heterogeneity of clinical profiles and depression subtypes. Additionally, patient comorbidities, preferences, and likelihood of adhering to treatment must all be considered when selecting an appropriate therapy. With the majority of prescriptions being written by primary care practitioners, it is appropriate to review the unique characteristics of all available antidepressants, including safety considerations. Prior to initiating antidepressant treatment and when patients do not respond adequately to initial therapy and/or exhibit any hypomanic or manic symptoms, bipolar disorder must be ruled out, and evaluation for psychiatric comorbidities must be considered as well. Patients with an inadequate response may then require a treatment switch to another drug with a different mechanism of action, combination, or augmentation strategy. In this narrative review, we propose that careful selection of the most appropriate antidepressant for adult patients with MDD based on their clinical profile and comorbidities is vital for initial treatment selection.Strategies must be considered for addressing partial and inadequate responses as well to help patients achieve full remission and sustained functional recovery. This review also highlights data for MDD clinical outcomes for which gaps in the literature have been identified, including the effects of antidepressants on functional outcomes, sleep disturbances, emotional and cognitive blunting, anxiety, and residual symptoms of depression.

Role of the Intestinal Microbiota in the Genesis of Major Depression and the Response to Antidepressant Drug Therapy: A Narrative Review

A major depressive disorder is a serious mental illness characterized by a pervasive low mood that negatively concerns personal life, work life, or education, affecting millions of people worldwide. To date, due to the complexity of the disease, the most common and effective treatments consist of a multi-therapy approach, including psychological, social, and pharmacological support with antidepressant drugs. In general, antidepressants are effective in correcting chemical imbalances of neurotransmitters in the brain, but recent evidence has underlined the pivotal role of gut microbiota (GM) also in the regulation of their pharmacokinetics/pharmacodynamics, through indirect or direct mechanisms. The study of these complex interactions between GM and drugs is currently under the spotlight, and it has been recently named "pharmacomicrobiomics". Hence, the purpose of this review is to summarize the contribution of GM and its metabolites in depression, as well as their role in the metabolism and activity of antidepressant drugs, in order to pave the way for the personalized administration of antidepressant therapies.

The development and internal evaluation of a predictive model to identify for whom Mindfulness-Based Cognitive Therapy (MBCT) offers superior relapse prevention for recurrent depression versus maintenance antidepressant medication

Depression is highly recurrent, even following successful pharmacological and/or psychological intervention. We aimed to develop clinical prediction models to inform adults with recurrent depression choosing between antidepressant medication (ADM) maintenance or switching to Mindfulness-Based Cognitive Therapy (MBCT). Using data from the PREVENT trial (N=424), we constructed prognostic models using elastic net regression that combined demographic, clinical and psychological factors to predict relapse at 24 months under ADM or MBCT. Only the ADM model (discrimination performance: AUC=.68) predicted relapse better than baseline depression severity (AUC=.54; one-tailed DeLong's test: z=2.8, p=.003). Individuals with the poorest ADM prognoses who switched to MBCT had better outcomes compared to those who maintained ADM (48% vs. 70% relapse, respectively; superior survival times [z=-2.7, p=.008]). For individuals with moderate-to-good ADM prognosis, both treatments resulted in similar likelihood of relapse. If replicated, the results suggest that predictive modeling can inform clinical decision-making around relapse prevention in recurrent depression.

Early Response to Antidepressant Medications in Adults With Major Depressive Disorder: A Naturalistic Study and Odds of Remission at 14 Weeks

PURPOSE/BACKGROUND

Early response after 2 to 4 weeks of antidepressant therapy has been shown to predict remission by 8 to 12 weeks. Most of the work to date on early response has been done using data from randomized controlled trials.

METHODS/PROCEDURES

This naturalistic study uses archival data from a national tele-mental health company. The positive and negative predictive values as well as sensitivity and specificity were calculated using different drops in baseline Patient Health Questionnaire 9 scores at various periods. Demographic and clinical characteristics were compared between early responders versus those lacking early response. Binary logistic regression analyses determined if early response was predictive of remission, response, and greater than minimal improvement at 14 weeks. For those who do not show early improvement, treatments were investigated using binary logistic regression to see if changes predicted later outcomes.

FINDINGS/RESULTS

Positive predictive values for all endpoints improved with the strength of early response but did not improve much with the time allowed for that response to occur. In contrast, negative predictive values increased substantially with time. Using a definition of 30% drop in Patient Health Questionnaire 9 score at week 4, 56.5% of patients were early responders. Early responders were ~3.2 times more likely to achieve remission than those lacking early response. Of nonresponders by week 4, those prescribed atypical antipsychotics (+SSRI) had significantly reduced odds of response at week 14, whereas those prescribed a norepinephrine and dopamine reuptake inhibitor had increased odds.

IMPLICATIONS/CONCLUSIONS

Early response may be associated with better outcomes at 14 weeks. In those with lack of response by week 4, patients prescribed a norepinephrine and dopamine reuptake inhibitor may achieve superior outcomes.

Behavioral effects of a low molecular weight peptide fraction from Phaseolus vulgaris in rats

Seminal studies stated that bean proteins are efficient neuronal tracers with affinity for brain tissue. A low molecular weight peptide fraction (<3kDa) from Phaseolus vulgaris (PV3) was previously reported to be antioxidant, non-cytotoxic, and capable of reducing reactive oxygen species and increasing nitric oxide in cells. We evaluated the effects of PV3 (5, 50, 100, 500, and 5000 µg/kg) on behavior and the molecular routes potentially involved. Acute and chronic PV3 treatments were performed before testing Wistar rats: i) in the elevated plus-maze (EPM) to assess the anxiolytic-like effect; ii) in the open field (OF) to evaluate locomotion and exploration; and iii) for depression-like behavior in forced swimming (FS). Catecholaminergic involvement was tested using the tyrosine hydroxylases (TH) enzyme inhibitor, α-methyl-DL-tyrosine (AMPT). Brain areas of chronically treated groups were dissected to assess: i) lipid peroxidation (LPO); ii) carbonylated proteins (CP); iii) superoxide dismutase (SOD) and catalase (CAT) enzymatic activities. Neuronal nitric oxide synthases (nNOS) and argininosuccinate synthase (ASS) protein expression was evaluated by western blotting. Acute treatment with PV3 increased the frequency and time spent in the EPM open arms, suggesting anxiolysis. PV3 increased crossing episodes in the OF. These PV3 effects on anxiety and locomotion were absent in the chronically treated group. Acute and chronic PV3 treatments reduced the immobility time in the FS test, suggesting an antidepressant effect. TH inhibition by AMPT reverted acute PV3 effects. PV3 decreased LPO and CP levels and SOD and CAT activities, whereas nNOS and ASS were reduced in few brain areas. In conclusion, PV3 displayed central antioxidant actions that are concomitant to catecholaminergic-dependent anxiolytic and antidepressant effects.

Randomized, Placebo-Controlled Trial of the Angiotensin Receptor Antagonist Losartan for Posttraumatic Stress Disorder

BACKGROUND

Evidence-based pharmacological treatments for posttraumatic stress disorder (PTSD) are few and of limited efficacy. Previous work suggests that angiotensin type 1 receptor inhibition facilitates fear inhibition and extinction, important for recovery from PTSD. This study tests the efficacy of the angiotensin type 1 receptor antagonist losartan, an antihypertensive drug, repurposed for the treatment of PTSD.

METHODS

A randomized controlled trial was conducted for 10 weeks in 149 men and women meeting DSM-5 PTSD criteria. Losartan (vs. placebo) was flexibly titrated from 25 to 100 mg/day by week 6 and held at highest tolerated dose until week 10. Primary outcome was the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) change score at 10 weeks from baseline. A key secondary outcome was change in CAPS-5 associated with a single nucleotide polymorphism of the ACE gene. Additional secondary outcomes included changes in the PTSD Checklist for DSM-5 and the Patient Health Questionnaire-9, and proportion of responders with a Clinical Global Impressions-Improvement scale of "much improved" or "very much improved."

RESULTS

Both groups had robust improvement in PTSD symptoms, but there was no significant difference on the primary end point, CAPS-5 measured as week 10 change from baseline, between losartan and placebo (mean change difference, 0.9, 95% confidence interval, -3.2 to 5.0). There was no significant difference in the proportion of Clinical Global Impressions-Improvement scale responders for losartan (58.6%) versus placebo (57.9%), no significant differences in changes in PTSD Checklist for DSM-5 or Patient Health Questionnaire-9, and no association between ACE genotype and CAPS-5 improvement on losartan.

CONCLUSIONS

At these doses and durations, there was no significant benefit of losartan compared with placebo for the treatment of PTSD. We discuss implications for failure to determine the benefit of a repurposed drug with strong a priori expectations of success based on preclinical and epidemiological data.

Selective Serotonin Reuptake Inhibitors: How Long Is Long Enough?

Selective serotonin reuptake inhibitors (SSRIs) are among the most commonly prescribed medications. They are among the first-line medications for several chronic or relapsing-remitting psychiatric conditions, including major depressive disorder and anxiety disorders. The advantages of SSRI use include ease of titration and their tolerability and safety profile. Guidelines for the short-term use of SSRIs are widely available, but there is no well-organized guidance on how and whether to maintain a patient on SSRIs for the long-term. In this article, we discuss the benefits and possible adverse consequences of long-term SSRI use, as well as clinical practice considerations when using SSRIs chronically. The major benefit of long-term SSRI use is relapse prevention. The current literature suggests that the general health risks of long-term SSRI use are low; however, further research, particularly in special populations including youth and the elderly, is needed. Long-term SSRI use increases the risk of tachyphylaxis and discontinuation syndrome. Recognizing that many patients may remain on SSRIs for many years, there are several factors that prescribers should consider if they choose to use an SSRI when initiating treatment and during long-term monitoring. The decision to continue or to discontinue an SSRI should be an active one, involving both the patient and prescriber, and should be revisited periodically. Patients who remain on SSRIs for the long-term should also have periodic monitoring to reassess the risk-benefit ratio of remaining on the SSRI, as well as to assess the safety, tolerability, and efficacy of the medication.

Steroid Phobia: Is There a Basis? A Review of Topical Steroid Safety, Addiction and Withdrawal

There is a growing concern amongst patients about topical corticosteroid (TCS) side effects, with increasing discussion of topical steroid addiction (TSA) and topical steroid withdrawal (TSW) particularly on social media platforms. However, the acceptance of TSA/TSW as a distinct condition remains controversial within the dermatological community. We conducted a literature search using PubMed, MEDLINE, Cochrane Library, Google Scholar, Embase and Web of Science to identify original articles addressing TSA/TSW. We described the definition and reported clinical features of TSA/TSW including its classification into erythemato-edematous and papulopustular subtype. To assess the validity of TSA/TSW, we summarised and objectively appraised the postulated mechanisms for this condition, including tachyphylaxis, dysregulation of glucocorticoid receptors, rebound vasodilation and impaired skin barrier leading to a cytokine cascade. Understanding the evidence including its limitations and uncertainties highlights areas for future research and helps medical practitioners better counsel and provide care to patients who may be experiencing or who have concerns about TSA/TSW.

Can loss of agency and oppositional perturbation associated with antidepressant monotherapy and low-fidelity psychological treatment dilute the benefits of guideline-consistent depression treatment at the population level?

Despite major expansions of evidence-based treatments of common mental disorders in recent decades, especially antidepressant medication, the point prevalence of depression has not decreased; instead it probably increased in young adults. We question whether antidepressants (AD)-monotherapy and low-fidelity-to-guideline psychological treatment (PT) might have no effect or even adverse effects in some patients and contexts that dilute the benefits of treatment at the population level, making it harder for population-based studies to detect treatment-driven prevalence reductions. Randomized Clinical Trial (RCT)s have not identified these effects because AD-monotherapy and low-fidelity PT are uncommon in RCTs where treatment protocols are specified and carefully monitored, unlike treatment in real-world settings. Second, RCTs may have missed the bigger picture of ultimate outcomes due to too short follow-ups. We elaborate two mechanisms through which AD-monotherapy and low-fidelity PT could produce adverse effects on long-term illness course. Both mechanisms are speculative and we outline how to test.

May antidepressant drugs worsen the conditions they are supposed to treat? The clinical foundations of the oppositional model of tolerance

In recent years there has been a considerable debate on antidepressant drugs. Continued drug treatment with antidepressant medications may stimulate processes that run counter to the initial acute effects of a drug. The oppositional model of tolerance may explain loss of treatment efficacy during maintenance treatment and the fact that some side effects tend to occur only after a certain time. These processes may also direct the illness into a treatment-unresponsive course, including manifestations of bipolar disorder or paradoxical reactions. When drug treatment ends, oppositional processes no longer encounter resistance, resulting in potential onset of new withdrawal symptoms, persistent post-withdrawal disorders, hypomania, and resistance to treatment if it is reinstituted. In all these cases, antidepressant medications may constitute a form of iatrogenic comorbidity, which increases chronicity and vulnerability to depressive episodes. Antidepressant medications are essential drugs for the treatment of major depressive episodes. They are less likely, however, to provide protection for relapse prevention. Current prescription practices need to be reformulated in light of consideration of vulnerabilities and adverse effects of treatment. The oppositional model of tolerance provides a conceptual framework for weighing all these elements in the individual case. The model does not appear to apply to all patients who undergo treatment with AD, but only to a part of them. Studying the variables that are associated with such occurrence in certain patients and not in others would be one of the most important tasks of current therapeutic research. Current diagnostic systems in psychiatry do not consider the iatrogenic components of psychopathology, and can be applied to only patients who are drug free. They are suited for a patient who no longer exists: most of the cases that are seen in psychiatric clinical practice receive psychotropic drugs and such treatment is likely to affect prognosis and treatment choices.

Disruption of Neural Homeostasis as a Model of Relapse and Recurrence in Late-Life Depression

The significant public health burden associated with late-life depression (LLD) is magnified by the high rates of recurrence. In this manuscript, we review what is known about recurrence risk factors, conceptualize recurrence within a model of homeostatic disequilibrium, and discuss the potential significance and challenges of new research into LLD recurrence. The proposed model is anchored in the allostatic load theory of stress. We review the allostatic response characterized by neural changes in network function and connectivity and physiologic changes in the hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system, and circadian rhythm. We discuss the role of neural networks' instability following treatment response as a source of downstream disequilibrium, triggering and/or amplifying abnormal stress response, cognitive dysfunction and behavioral changes, ultimately precipitating a full-blown recurrent episode of depression. We propose strategies to identify and capture early change points that signal recurrence risk through mobile technology to collect ecologically measured symptoms, accompanied by automated algorithms that monitor for state shifts (persistent worsening) and variance shifts (increased variability) relative to a patient's baseline. Identifying such change points in relevant sensor data could potentially provide an automated tool that could alert clinicians to at-risk individuals or relevant symptom changes even in a large practice.

Antidepressants for Preventive Treatment of Migraine

PURPOSE OF REVIEW

This review describes the pharmacology of each antidepressant class as it applies to migraine prevention, summarizes the evidence base for each medication, and describes relevant side effects and clinical considerations. Use of antidepressants for migraine prevention in clinical practice is also discussed.

RECENT FINDINGS

Antidepressants are commonly used as migraine preventives. Amitriptyline has the best evidence for use in migraine prevention. Nortriptyline is an alternative in patients who may not tolerate amitriptyline. The sedating effect of TCAs can be beneficial for patients with comorbid insomnia. SNRIs including venlafaxine and duloxetine also have evidence for efficacy and may be the most effective treatments in patients with comorbid depression and migraine. SSRIs including fluoxetine are not effective for most patients. The side effect burden of antidepressants can be substantial. Patients should be particularly counseled about the possibility of a withdrawal effect from SNRIs. Antidepressants are an important option for preventive treatment of migraine. Further research on the efficacy and tolerability of SNRIs as migraine preventives is needed.