Cognitive remediation therapy for patients with bipolar disorder: A randomised proof-of-concept trial

Thinking About the Future of Cognitive Remediation Therapy Revisited: What Is Left to Solve Before Patients Have Access?

In our previous paper on the Future of Cognitive Remediation published more than 10 years ago, we envisaged an imminent and wide implementation of cognitive remediation therapies into mental health services. This optimism was misplaced. Despite evidence of the benefits, costs, and savings of this intervention, access is still sparse. The therapy has made its way into some treatment guidance, but these documents weight the same evidence very differently, causing confusion, and do not consider barriers to implementation. This paper revisits our previous agenda and describes how some challenges were overcome but some remain. The scientific community, with its commitment to Open Science, has produced promising sets of empirical data to explore the mechanisms of treatment action. This same community needs to understand the specific and nonspecific effects of cognitive remediation if we are to provide a formulation-based approach that can be widely implemented. In the last 10 years we have learned that cognitive remediation is not "brain training" but is a holistic therapy that involves an active therapist providing motivation support, and who helps to mitigate the impact of cognitive difficulties through metacognition to develop awareness of cognitive approaches to problems. We conclude that, of course, more research is needed but, in addition and perhaps more importantly at this stage, we need more public and health professionals' understanding of the benefits of this therapy to inform and include this approach as part of treatment regimens.

A Systematic Review and Narrative Synthesis of Cognitive Training in the Treatment of Mental Illness and Substance Use Disorder

Introduction: The one unifying and distinguishing feature of all neuropsychiatric illnesses is the co-occurrence of cognitive dysfunction. Cognitive training (CT) was developed to enhance neural connectivity and cognition and improve day-to-day functioning. However, the benefits of CT are still debated. This current systematic review aimed to examine the efficacy of CT and to identify diagnostic and CT characteristics associated with superior outcomes across a range of psychiatric disorders. Method: Studies investigating CT in psychiatric illnesses were extracted from Embase, PubMed, CINAHL, PsycINFO, and PsycARTICLES up to 17 August 2023. Inclusion criteria were randomised control trials (RCT) and English language. The primary search strategy included terms relating to cognitive training, cognitive remediation, cognitive enhancement, or cognitive rehabilitation and randomised control trials, clinical trials, or experiments. Risk of bias was assessed using RevMan Web version 8.1.1. Narrative synthesis was used to analyse findings. Due to the heterogeneity of participant demographics, diagnoses, and interventions, meta-analyses were considered inappropriate. Results: Fifteen studies, including a total of 1075 participants, were identified. Approximately 67% of studies reported significant improvements in at least one trained domain of cognitive function after CT, and 47% observed improvements in psychiatric symptoms or function. Cognitive transfer effects were not observed. Sample sizes for studies were generally small, and most CT durations were 6 weeks or less. Conclusions: Findings suggest that CT can improve cognitive function in trained domains, though little evidence of cognitive transfer effects was observed. Due to the lack of standardisation in CT format and delivery, and inadequate measures of psychiatric symptoms or daily function, there is insufficient evidence to conclude whether or not this technique may benefit cognitive impairment in psychiatric disorders, or lead to subsequent improvement in disease symptomatology. Further studies of longer duration and using consistent methodologies must be conducted to identify the benefits of CT in psychiatric disorders.

Cognitive rehabilitation in bipolar spectrum disorder: A systematic review

Background and objectives

Neurocognitive deficits in bipolar disorder (BD) have a negative impact on the quality of life, even during the euthymic phase. And many studies conducted to improve cognitive deficits in bipolar disorder. This systematic review aims to summarize studies on cognitive rehabilitation (CR) conducted in bipolar patients and evaluate its impact on neurocognitive deficits. The primary objective is to explore how CR interventions can enhance cognitive functioning, treatment outcomes, and overall quality of life in this population.

Methods

A comprehensive search was conducted on PubMed, Google Scholar, Scopus, Embase, and PsycINFO databases from 1950 to 2023, following the 2015 PRISMA-P guidelines, using search terms related to BD and CR.

Results

The initial search yielded 371 titles across the five databases. After applying inclusion and exclusion criteria through screening, a total of 23 articles were included in the study. The selected articles evaluated verbal memory, attention, executive functions, and social cognition.

Conclusion

The findings suggest that CR can be an effective treatment approach for bipolar patients, aimed at enhancing their cognitive abilities, treatment outcomes, and overall quality of life. The primary finding of this study indicates that cognitive-behavioral therapy (CBT) protocols, skill training, and homework exercises, which offer a daily structure, social support, and opportunities for exchanging coping strategies, are more effective in enhancing cognitive functions. However, it is important to acknowledge the notable limitations of this review. Firstly, we did not assess the methodological rigor of the included studies. Additionally, there was a lack of detailed analysis regarding specific cognitive rehabilitation approaches that adhere to core CR principles, resulting in increased heterogeneity within the reviewed studies.

Impact of cognitive reserve on bipolar disorder: a systematic review

Background

Cognitive reserve (CR) is a complex concept that includes premorbid IQ, years of education, and exposure to neuropsychological stimuli through work and leisure. Previous studies have suggested that CR has a positive impact on several aspects of bipolar disorder. Synthesizing the evidence to date is an important work in providing directions for future studies. The objectives of this systematic review to summary impact of CR on onsetting, relapsing bipolar episodes, buffering cognitive dysfunctions, and maintaining quality of life (QOL) in bipolar disorder.

Methods

Two researchers independently reviewed selected paper from three database as PubMed, PsychINFO, and Web of Science. The search keywords were "bipolar disorder" and "cognitive reserve." The selected studies were classified as the levels of evidence according to the criteria of the Oxford Center for Evidence- Based Medicine. The results of the selected studies were summarized according to the objectives.

Results

Thrity six studies were included in this review. People with high CR may have fewer bipolar episodes and alleviate cognitive impairments and dysfunction. CR may keep the functional level in patients with bipolar disorder.

Conclusion

The results of this systematic review suggest that CR may be involved in preventing relapse of bipolar episodes and may alleviate cognitive dysfunction. However, effect on prevention of onset-risk and relapse of bipolar episodes need further investigation in prospective studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021270293, the protocol was registered with PROSERO (CRD42021270293).

The impact of depressive symptoms on cognitive impairments in chronic ketamine users

BACKGROUND

Chronic ketamine use has been associated with cognitive impairments, while depressive symptoms are commonly observed in individuals using ketamine. However, the influence of depressive symptoms on cognitive impairments in chronic ketamine users remains unclear. This study aimed to examine the impact of depressive symptoms on cognitive function in this population.

METHODS

A cross-sectional study was conducted with a sample of chronic ketamine users. Participants underwent comprehensive cognitive assessments, including measures of attention, executive function, working memory, verbal and visual memory. Depressive symptoms were assessed using Beck Depression Inventory (BDI) scores. Multivariate analyses were utilized to compare the cognitive performance of individuals who use ketamine, both with and without depressive symptoms, as well as a control group, while controlling for relevant covariates.

RESULTS

The results revealed a significant negative impact of depressive symptoms on cognitive impairments, particularly in the domains of memory and executive function, among chronic ketamine users. The analysis of partial correlations revealed that among individuals who use ketamine and have depressive symptoms, those with higher levels of depressive symptoms demonstrated poorer cognitive performance compared to individuals with lower levels of depressive symptoms, controlling for potential confounding factors.

CONCLUSIONS

The findings suggest that depressive symptoms contribute to cognitive impairments, specifically in memory and executive function, in chronic ketamine users. Therefore, it is crucial to evaluate depressive symptoms when considering cognitive enhancement treatment for this population.

Cognitive Remediation in Bipolar (CRiB2): study protocol for a randomised controlled trial assessing efficacy and mechanisms of cognitive remediation therapy compared to treatment as usual

BACKGROUND

A substantial proportion of people with bipolar disorder (BD) experience persistent cognitive difficulties associated with impairments in psychosocial functioning and a poorer disorder course. Emerging evidence suggests that cognitive remediation (CR), a psychological intervention with established efficacy in people with schizophrenia, can also benefit people with BD. Following a proof-of-concept trial showing that CR is feasible and potentially beneficial for people with BD, we are conducting an adequately powered trial in euthymic people with BD to 1) determine whether an individual, therapist-supported, computerised CR can reduce cognitive difficulties and improve functional outcomes; and 2) explore how CR exerts its effects.

METHODS

CRiB2 is a two-arm, assessor-blind, multi-site, randomised controlled trial (RCT) comparing CR to treatment-as-usual (TAU). Participants are people with a diagnosis of BD, aged between 18 and 65, with no neurological or current substance use disorder, and currently euthymic. 250 participants will be recruited through primary, secondary, tertiary care, and the community. Participants will be block-randomised (1:1 ratio, stratified by site) to continue with their usual care (TAU) or receive a 12-week course of therapy and usual care (CR + TAU). The intervention comprises one-on-one CR sessions with a therapist supplemented with independent cognitive training for 30-40 h in total. Outcomes will be assessed at 13- and 25-weeks post-randomisation. Efficacy will be examined by intention-to-treat analyses estimating between-group differences in primary (i.e., psychosocial functioning at week 25 measured with the Functional Assessment Short Test) and secondary outcomes (i.e., measures of cognition, mood, patient-defined goals, and quality of life). Global cognition, metacognitive skills, affect fluctuation, and salivary cortisol levels will be evaluated as putative mechanisms of CR through mediation models.

DISCUSSION

This study will provide a robust evaluation of efficacy of CR in people with BD and examine the putative mechanisms by which this therapy works. The findings will contribute to determining the clinical utility of CR and potential mechanisms of action.

TRIAL REGISTRATION

Cognitive Remediation in Bipolar 2 (CRiB2): ISRCTN registry: https://www.isrctn.com/ISRCTN10362331 . Registered 04 May 2022. Overall trial status: Ongoing; Recruitment status: Recruiting.

Is brain perfusion correlated to switching mood states and cognitive impairment in bipolar disorder type I? A longitudinal study using perfusion imaging approach

Type I Bipolar disorder (BD-I) is a neuropsychiatric disorder characterized by manic or mixed-featured episodes, impaired cognitive functioning, and persistent work and social functioning impairment. This study aimed to investigate within-subject; (i) differences in brain perfusion using Single-photon emission computed tomography (SPECT) between manic and euthymic states in BD-I patients; (ii) explore potential associations between altered brain perfusion and cognitive status; and (iii) examine the relationship between cerebral perfusion and mania symptom ratings. Seventeen adult patients diagnosed with BD-I in a manic episode were recruited, and clinical assessments, cognitive tests, and brain perfusion studies were conducted at baseline (mania state) and a follow-up visit 6 months later. The results showed cognitive impairment during the manic episode, which persisted during the euthymic state at follow-up. However, no significant changes in brain perfusion were observed between the manic and euthymic states. During mania, trends toward decreased perfusion in the left cerebellum and right superior parietal lobule were noted. Additionally, trends indicated a higher perfusion imbalance in the left superior and middle frontal gyrus during mania and the right superior and middle frontal gyrus during euthymia. No significant correlations existed between brain perfusion, mania symptom ratings, and cognitive performance, indicating that symptomatology might represent more than neural hemodynamics. These findings suggest that cognitive impairment may persist in BD-I patients and highlight the need for therapeutic interventions targeting cognitive deficits. More extensive studies with extended follow-up periods are warranted further to investigate brain perfusion and cognitive functioning in BD-I patients.

Efficacy of cognitive remediation in bipolar disorder: systematic review and meta-analysis of randomized controlled trials

A significant percentage of people with bipolar disorder (BD) exhibit suboptimal functional adjustment, even when appropriately treated and after symptomatic recovery is achieved. Given that cognitive impairment is one of the strongest correlates of socio-occupational outcomes and quality of life in BD, cognitive remediation (CR) is currently acknowledged as a promising treatment that could help bridge the gap between symptomatic and full functional recovery. The aim of this review was to explore the efficacy of CR approaches in improving cognitive and functional outcomes in BD patients. PubMed, PsycINFO, and CENTRAL were searched from inception to November 2022. Randomized controlled trials exploring the effects of CR on cognition and/or functional adjustment in adult BD patients were eligible. Ten studies based on seven independent trials (n = 586) were included. Change-score effect sizes (Hedges' g) were obtained for efficacy outcome measures and combined by means of meta-analytic procedures. Small but significant overall effects were observed for working memory (g = 0.32, 95% CI 0.11-0.52), planning (g = 0.30, 95% CI 0.03-0.56), and verbal learning (g = 0.40, 95% CI 0.15-0.66). However, CR was not found to exert any significant effects on functional outcomes at treatment completion or at follow-up assessment. Although CR may modestly enhance the cognitive performance of BD patients, this effect does not translate into an improvement at the functional level. The current data do not support the inclusion of CR as a treatment recommendation in clinical practice guidelines for the management of BD.

Efficacy of Functional Remediation on Cognitive and Psychosocial Functioning in Patients with Bipolar Disorder: Study Protocol for a Randomized Controlled Study

BACKGROUND

Neurocognitive impairment is a prominent characteristic of bipolar disorder (BD), linked with poor psychosocial functioning. This study's purpose is to evaluate the effectiveness of functional remediation (FR) in enhancing neurocognitive dysfunctions in a sample of remitted patients with diagnosis of BD in comparison to treatment as usual-TAU. To quantify the neurocognitive damage, the Brief Assessment of Cognition in Affective Disorders (BAC-A) will be used, and the overall psychosocial functioning will be measured with the Functioning Assessment Short Test-FAST.

METHODS

The randomized, rater-blinded, controlled study will include two arms (1:1) encompassing 54 outpatients with diagnosis of BD-I and BD-II, as defined by the DSM-5 criteria. In the experimental phase, remitted patients aged 18-55 years will be involved. At the baseline, at the end of intervention and at the 6-month follow-up, patients will be evaluated using clinical scales (Young Mania Rating Scale (Y-MRS) and Hamilton Depression Rating Scale (HAM-D)). Neurocognitive measurements and psychosocial functioning will be valued, respectively, with BAC-A and FAST.

DISCUSSION

The primary expected outcome is that following FR intervention, patients will exhibit improved cognitive abilities and psychosocial outcomes compared to the participants in the TAU group. It is now recognized that neurocognitive deficits are potential predictors of functional outcome in patients with BD. In recent years, there has been a growing interest in the implementation of interventions that, in addition to symptomatic remission, are also aimed at neurocognitive dysfunctions in order to achieve a recovery of psychosocial functioning.

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.

An update on potential pharmacotherapies for cognitive impairment in bipolar disorder

INTRODUCTION

Cognitive impairment is a core feature of bipolar disorder (BD) that impedes recovery by preventing the return to optimal socio-occupational functioning and reducing quality of life. Presently, there are no efficacious treatments for cognitive impairment in BD, but many pharmacological interventions are being considered as they have the potential to target the underlying pathophysiology of the disorder.

AREAS COVERED

This review summarizes the available evidence for pharmacological interventions for cognitive impairment in bipolar disorder. We searched PubMed, MedLine, and PsycInfo from inception to December 1^st, 2022. Traditional treatments, such as lithium, anticonvulsants (lamotrigine), antipsychotics (aripiprazole, asenapine, cariprazine, lurasidone, and olanzapine), antidepressants (vortioxetine, fluoxetine, and tianeptine) and psychostimulants (modafinil), and emerging interventions, such as acetylcholinesterase inhibitors (galantamine and donepezil), dopamine agonists (pramipexole), erythropoietin, glucocorticoid receptor antagonists (mifepristone), immune modulators (infliximab, minocycline and doxycycline), ketamine, metabolic agents (insulin, metformin, and liraglutide), probiotic supplements, and Withania somnifera are discussed.

EXPERT OPINION

The investigation of interventions for cognitive impairment in BD is a relatively under-researched area. In the past, methodological pitfalls in BD cognition trials have also been a critical limiting factor. Expanding on the existing literature and identifying novel pharmacological and non-pharmacological treatments for cognitive impairment in BD should be a priority.

Does cognitive improvement translate into functional changes? Exploring the transfer mechanisms of cognitive remediation therapy for euthymic people with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is associated with cognitive and functional difficulties, persistent beyond mood episodes. Cognitive remediation (CR) is a psychological therapy targeting cognitive and functioning difficulties. Recent evidence suggests that CR may enhance long-term functioning but transfer mechanisms on functional outcomes have not been explored. We aim to investigate whether and how cognitive gains after CR transfer to functional improvement.

METHODS

We considered data from a randomized controlled trial comparing CR (n = 40) to treatment-as-usual (TAU; n = 40) in euthymic people with BD. Treatment outcomes included individual cognitive domains and global cognition, psychosocial functioning, and goal attainment. Regression-based mediation and moderation modelling were used to assess whether and how post-treatment cognitive changes translate into functional improvement at follow-up, three months after treatment end.

RESULTS

Cognitive gains after CR transferred to functional changes three months later: improvement in post-treatment global cognition partially mediated the effect of CR on psychosocial functioning (standardized indirect effect: -0.23, 95% CI -0.51 to -0.04). Goal attainment was not significantly mediated by changes in cognition, but post-treatment cognitive performance moderated the effect of CR on the GAS at follow-up (interaction effect: 0.78, 95% CI 0.08-1.55).

CONCLUSIONS

Our findings suggest that cognitive improvements contribute to functional improvement but transfer mechanisms differ between psychosocial functioning and idiosyncratic recovery goals. Cognition accounted for only a proportion of the total CR effect on functional outcomes. Future studies should consider other variables, such as metacognition, that may drive the transfer of CR effects to functional outcomes.

Cognitive rehabilitation in post-COVID-19 condition: A study protocol for a randomized controlled trial

BACKGROUND

Post-COVID-19 condition is frequently comprised of persistent cognitive sequela, including deficits in attention and executive functions (EFs), which can act as a barrier for regaining pre-illness functional levels. Goal Management Training (GMT) is a cognitive rehabilitation (CR) intervention for improving attention and EFs that has received empirical support in studies of other patient groups. The present study aims to determine the efficacy of GMT for improving everyday attention and EFs in adults who experience persistent cognitive deficits after COVID-19.

METHODS

This study protocol describes an open-label randomized controlled trial comparing the efficacy of GMT to a wait list control condition (WL), for improving persistent (> 2 months) cognitive sequela in post-COVID-19 condition. The study aims to recruit 240 participants aged 18 to 65 years with a history of SARS-CoV-2 infection and perceived attentional and EF difficulties in daily life. Participants will be block randomized (computer-algorithm) to either group-based GMT (n = 120) or WL (n = 120). GMT will be internet-delivered to groups of six participants in six two-hour sessions delivered once a week. The primary outcome will be the Metacognition Index of the Behavior Rating Inventory of Executive Function - Adult Version, a self-report measure assessing everyday EF difficulties, specifically metacognition, at six months post-treatment. Secondary outcomes include performance-based neurocognitive measures, and tertiary outcomes include rating scales of cognition, emotional health, quality of life, and fatigue.

CONCLUSION

Study findings could contribute to providing an evidence-based treatment option for symptoms that are frequent and debilitating following a prevalent condition.

TRIAL REGISTRATION NUMBER

NCT05494424.

Cognitive remediation for people with bipolar disorder: The contribution of session attendance and therapy components to cognitive and functional outcomes

BACKGROUND

Cognitive remediation (CR) can reduce cognitive and functional difficulties in people with bipolar disorder (BD). To date, there is limited evidence on the contribution of session attendance and therapy components to treatment outcomes. This study explores whether attendance and core CR components contribute to treatment outcomes.

METHODS

This is a secondary analysis using data from a randomized controlled trial comparing CR plus treatment-as-usual (TAU; n = 40) to TAU only (n = 40) in euthymic people with BD. Session attendance was measured by number of sessions and by achieving therapy completion, pre-defined as attending ≥20 sessions. We used instrumental variable analysis to examine the effect of attendance on treatment outcomes. We then considered the association between core therapy components (i.e., massed practice, errorless learning, strategy use, therapist contact) and post-treatment outcome changes using correlation.

RESULTS

The CR group improved significantly in measure of global cognition, psychosocial functioning, and goal attainment. Therapy recipients attended 27.1 sessions on average, with 32 (80%) completing the minimum number of 20 sessions. Attending more sessions and achieving therapy completion were associated with improved treatment outcomes, but this relationship was not significant within the subgroup of CR completers. Improvement in psychosocial functioning was associated with therapist contact and goal attainment with selecting useful strategies during therapy.

CONCLUSIONS

Our findings highlight the relevance of session attendance, specifically the importance of achieving a minimum threshold of CR sessions, for outcome improvement. Strategy use and therapist contact might facilitate improvements in psychosocial functioning and personal recovery goals.

Randomised controlled cognition trials in remitted patients with mood disorders published between 2015 and 2021: A systematic review by the International Society for Bipolar Disorders Targeting Cognition Task Force

BACKGROUND

Cognitive impairments are an emerging treatment target in mood disorders, but currently there are no evidence-based pro-cognitive treatments indicated for patients in remission. With this systematic review of randomised controlled trials (RCTs), the International Society for Bipolar Disorders (ISBD) Targeting Cognition Task force provides an update of the most promising treatments and methodological recommendations.

METHODS

The review included RCTs of candidate pro-cognitive interventions in fully or partially remitted patients with major depressive disorder or bipolar disorder. We followed the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed/MEDLINE, PsycInfo, EMBASE and Cochrane Library from January 2015, when two prior systematic reviews were conducted, until February 2021. Two independent authors reviewed the studies with the Revised Cochrane Collaboration's Risk of Bias tool for Randomised trials.

RESULTS

We identified 16 RCTs (N = 859) investigating cognitive remediation (CR; k = 6; N = 311), direct current or repetitive magnetic stimulation (k = 3; N = 127), or pharmacological interventions (k = 7; N = 421). CR showed most consistent cognitive benefits, with two trials showing improvements on primary outcomes. Neuromodulatory interventions revealed no clear efficacy. Among pharmacological interventions, modafinil and lurasidone showed early positive results. Sources of bias included small samples, lack of pre-screening for objective cognitive impairment, no primary outcome and no information on allocation sequence masking.

CONCLUSIONS

Evidence for pro-cognitive treatments in mood disorders is emerging. Recommendations are to increase sample sizes, pre-screen for impairment in targeted domain(s), select one primary outcome, aid transfer to real-world functioning, investigate multimodal interventions and include neuroimaging.

The impact of substance use disorder comorbidity on cognition of individuals with bipolar disorder: A systematic review

The aim of this study is to describe whether Bipolar Disorder (BD) with Substance Use Disorder (SUD) comorbidity is associated with an increased cognitive impairment as compared to BD without SUD comorbidity. This is a systematic review. The literature search was conducted in three databases: PubMed, PsycINFO and Embase. A total of 2032 studies were screened after removing duplicates. 29 articles were included for full text screening, and a total of 14 articles were included in the systematic review. Multiple cognitive domains were assessed, including verbal, spatial and visual memory, and psychomotor and executive functioning. Over half the articles (64.3%, n=9) identified cognitive impairments in individuals with BD+SUD comorbidity as compared to individuals with BD without SUD comorbidity. In addition, individuals with the comorbidity exhibited more severe impairments on tests of executive functioning, and greater impairments in verbal and visual memory. The studies included in this systematic review reinforce that individual with comorbidity of BD and SUD have increased cognitive impairment as compared to individuals with BD without SUD comorbidity. Executive functioning was the most impaired cognitive domain found across the studies included in this review. Intervention strategies focused on executive functioning would be beneficial for this specific population.

A randomised controlled trial of psychotherapy and cognitive remediation to target cognition in mood disorders

OBJECTIVE

To examine the impact of a treatment package combining Interpersonal and Social Rhythm Therapy (IPSRT) and cognitive remediation (CR), vs IPSRT alone, on cognition, functioning, and mood disturbance outcomes in mood disorders.

METHODS

A pragmatic randomised controlled trial in adults with bipolar disorder (BD) or major depressive disorder (MDD), recently discharged from mental health services in Christchurch, New Zealand, with subjective cognitive difficulties. Individuals were randomised to a 12-month course of IPSRT with CR (IPSRT-CR), or without CR (IPSRT). In IPSRT-CR, CR was incorporated into therapy sessions from approximately session 5 and continued for 12 sessions. The primary outcome was change in Global Cognition (baseline to 12 months).

RESULTS

Sixty-eight individuals (BD n = 26, MDD n = 42; full/partial remission n = 39) were randomised to receive IPSRT-CR or IPSRT (both n = 34). Across treatment arms, individuals received an average of 23 IPSRT sessions. Change in Global Cognition did not differ between arms from baseline to treatment-end (12 months). Psychosocial functioning and longitudinal depression symptoms improved significantly more in the IPSRT compared with IPSRT-CR arm over 12 months, and all measures of functioning and mood symptoms showed moderate effect size differences favouring IPSRT (0.41-0.60). At 18 months, small to moderate, non-significant benefits (0.26-0.47) of IPSRT vs IPSRT-CR were found on functioning and mood outcomes.

CONCLUSIONS

Combining two psychological therapies to target symptomatic and cognitive/functional recovery may reduce the effect of IPSRT, which has implications for treatment planning in clinical practice and for CR trials in mood disorders.

Randomised controlled trial of Interpersonal and Social Rhythm Therapy and group-based Cognitive Remediation versus Interpersonal and Social Rhythm Therapy alone for mood disorders: study protocol

BACKGROUND

Individuals with mood disorders frequently experience cognitive impairment, which impacts on the long-term trajectory of the disorders, including being associated with persisting difficulties in occupational and psychosocial functioning, residual mood symptoms, and relapse. Current first-line treatments for mood disorders do little to improve cognitive function. Targeting cognition in clinical research is thus considered a priority. This protocol outlines a prospectively-registered randomised controlled trial (RCT) which examines the impact of adding group-based Cognitive Remediation (CR) to Interpersonal and Social Rhythm Therapy (IPSRT-CR) for individuals with mood disorders.

METHODS

This is a pragmatic, two-arm, single-blinded RCT comparing IPSRT-CR with IPSRT alone for adults (n = 100) with mood disorders (Major Depressive Disorder or Bipolar Disorder) with subjective cognitive difficulties, on discharge from Specialist Mental Health Services in Christchurch, New Zealand. Both treatment arms will receive a 12-month course of individual IPSRT (full dose = 24 sessions). At 6 months, randomisation to receive, or not, an 8-week group-based CR programme (Action-based Cognitive Remediation - New Zealand) will occur. The primary outcome will be change in Global Cognition between 6 and 12 months (treatment-end) in IPSRT-CR versus IPSRT alone. Secondary outcomes will be change in cognitive, functional, and mood outcomes at 6, 12, 18, and 24 months from baseline and exploratory outcomes include change in quality of life, medication adherence, rumination, and inflammatory markers between treatment arms. Outcome analyses will use an intention-to-treat approach. Sub-group analyses will assess the impact of baseline features on CR treatment response. Participants' experiences of their mood disorder, including treatment, will be examined using qualitative analysis.

DISCUSSION

This will be the first RCT to combine group-based CR with an evidence-based psychotherapy for adults with mood disorders. The trial may provide valuable information regarding how we can help promote long-term recovery from mood disorders. Many issues have been considered in developing this protocol, including: recruitment of the spectrum of mood disorders, screening for cognitive impairment, dose and timing of the CR intervention, choice of comparator treatment, and choice of outcome measures.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry, ACTRN12619001080112 . Registered on 6 August 2019.

Action-based cognitive remediation in bipolar disorder improved verbal memory but had no effect on the neural response during episodic memory encoding

Verbal memory and executive function impairments are common in remitted patients with bipolar disorder (BD). We recently found that Action-Based Cognitive Remediation (ABCR) may improve executive function and verbal memory in BD. Here, we investigated neuronal changes associated with ABCR treatment-related memory improvement in a longitudinal functional MRI (fMRI) study. Forty-five patients with remitted BD (ABCR: n = 26, control treatment: n = 19) completed a picture-encoding task during fMRI and tests of verbal memory and executive function outside the scanner before and after two weeks of ABCR/control treatment. The cognitive assessment was performed again following ten weeks of treatment. Thirty-four healthy controls underwent the same test protocol once for baseline comparisons. Patients showed a moderate improvement in a domain composite of verbal learning and memory both after two weeks and ten weeks of ABCR treatment, which correlated with improved executive function. At baseline, patients showed encoding-related hypoactivity in dorsal prefrontal cortex compared to healthy controls. However, treatment was not associated with significant task-related neuronal activity changes. Improved verbal learning and memory may have occurred through strengthened strategic processing targeted by ABCR. However, picture-encoding paradigms may be suboptimal to capture the neural correlates of this improvement, possibly by failing to engage strategic encoding processes.

Development of a Psychosocial Intervention to Promote Treatment Adherence in Patients with Bipolar Disorder at Risk of Cardiovascular Disease

Nonadherence to treatment is a serious concern that affects the successful management of bipolar disorder (BD) patients. The aim of this study was to pilot test a psychosocial intervention (previously developed by this team) intended to increase adherence to medication and health behaviors targeting cardiovascular disease (CVD) risk factors in BD patients. An open, single-group design was used to assess the feasibility and acceptability of the intervention. The participants had BD, type I/II or unspecified, and CVD risk factors. Baseline demographic measures were taken. We also obtained preliminary effect sizes related to pre-post changes on measures of self-reported adherence to psychiatric medication, depressive and manic symptoms, and pharmacy records. At baseline, 29% of the participants reported recent adherence to psychiatric medications. A total of 71% of the participants completed the intervention. Pre-post improvements by medium and large effect sizes (Cohen’s d = 0.52–0.92) were seen in medication adherence, attitudes toward medication, and mania symptoms. The participants reported high levels of satisfaction with the intervention. A culturally sensitive psychosocial intervention for Puerto Rican BD patients who are at risk of CVD was found to be feasible and acceptable. Improvements in the key outcomes were seen in this small, preliminary study. Further research is needed with a larger sample size.

Predictors of psychosocial functioning in euthymic patients with bipolar disorder: A model selection approach

BACKGROUND

Functional impairment is a major target in the treatment of bipolar disorder (BD), but the magnitude and type of functional difficulties differ across patients. Findings on predictors of overall functioning and specific functional areas are inconsistent. We aimed to characterize functional difficulties and identify factors associated with global functioning and individual domains in euthymic patients.

METHODS

The Functional Assessment Short Test (FAST) was used to assess overall psychosocial functioning and specific functional domains in 80 euthymic participants with BD. Participants also completed a clinical interview and a cognitive assessment. Model selection with elastic net regression was performed to identify predictors of global functioning. We then examined the association of these predictors with individual functional domains using correlation.

RESULTS

FAST scores indicated moderate or severe impairment for 54% of the sample, with occupational functioning showing the highest impairment rate. Elastic net regression selected a model with three variables (higher residual depressive symptoms, lower executive functioning, more perceived cognitive deficits) as predictors of overall functioning. No significant associations were found between these predictors. Depressive symptoms were associated with interpersonal relationships and leisure time, executive skills with occupational functioning, and perceived deficits with cognitive functioning.

CONCLUSIONS

Residual depressive symptoms were the strongest predictor of overall functioning which highlights the importance of assessing and targeting subthreshold symptoms for recovery. Executive difficulties were associated with functioning, particularly occupational skills, independently of depressive symptoms. Interventions targeting these difficulties, such as cognitive and functional remediation, may be key treatment options towards facilitating functional recovery.

A Systematic Review of Cognition-Brain Morphology Relationships on the Schizophrenia-Bipolar Disorder Spectrum

The nature of the relationship between cognition and brain morphology in schizophrenia-spectrum disorders (SSD) and bipolar disorder (BD) is uncertain. This review aimed to address this, by providing a comprehensive systematic investigation of links between several cognitive domains and brain volume, cortical thickness, and cortical surface area in SSD and BD patients across early and established illness stages. An initial search of PubMed and Scopus databases resulted in 1486 articles, of which 124 met inclusion criteria and were reviewed in detail. The majority of studies focused on SSD, while those of BD were scarce. Replicated evidence for specific regions associated with indices of cognition was minimal, however for several cognitive domains, the frontal and temporal regions were broadly implicated across both recent-onset and established SSD, and to a lesser extent BD. Collectively, the findings of this review emphasize the significance of both frontal and temporal regions for some domains of cognition in SSD, while highlighting the need for future BD-related studies on this topic.

Inflammatory biomarkers and cognitive functioning in individuals with euthymic bipolar disorder: exploratory study

BACKGROUND

Neurobiological research frequently implicates inflammatory and neurogenic components with core aspects of bipolar disorder. Even in periods of symptom remission (euthymia), individuals with bipolar disorder experience cognitive impairments, which are increasingly being proposed as an outcome for interventions; identifying biomarkers associated with cognitive impairment in people with bipolar disorder could advance progress in this therapeutic field through identifying biological treatment targets.

AIMS

We aimed to identify proteomic biomarker correlates of cognitive impairment in individuals with euthymic bipolar disorder.

METHOD

Forty-four adults with a bipolar disorder diagnosis in euthymia underwent a battery of cognitive assessments and provided blood for biomarkers. We examined a comprehensive panel of inflammatory and trophic proteins as putative cross-sectional predictors of cognition, conceptualised according to recommended definitions of clinically significant cognitive impairment (binary construct) and global cognitive performance (continuous measure).

RESULTS

A total of 48% of the sample met the criteria for cognitive impairment. Adjusting for potentially important covariates, regression analyses identified lower levels of three proteins as significantly and independently associated with cognitive deficits, according to both binary and continuous definitions (interleukin-7, vascular endothelial growth factor C and placental growth factor), and one positively correlated with (continuous) global cognitive performance (basic fibroblast growth factor).

CONCLUSIONS

This study identifies four candidate markers of cognitive impairment in bipolar disorder, none of which have been previously compared with cognitive function in participants with bipolar disorder. Pending replication in larger samples and support from longitudinal studies, these markers could have implications for treating cognitive dysfunction in this patient population.

Neurocognitive functioning in bipolar disorder: What we know and what we don’t

Introduction: This narrative review of systematic reviews and meta-analyses aims at compiling available evidence in various aspects of neurocognitive functioning in Bipolar Disorder (BD).

Methods: We conducted a MEDLINE literature search and identified 38 relevant systematic reviews and metaanalyses.

Results: Current evidence suggests that BD is associated with cognitive impairment across multiple domains and during all clinical states. However, there is a considerable cognitive heterogeneity within BD, which cannot be explained by clinical subtypes, and the pattern of neurocognitive impairment in BD overlaps with other psychiatric conditions such as major depression and schizophrenia. Residual depressive symptoms, poor clinical course and higher number of manic episodes may negatively impact cognitive performance, which is a major predictor of general functioning in BD. Evidence from available prospective studies does not support the notion of progressive cognitive decline in BD while some evidence exists to suggest patients may show some improvements in cognitive functioning following the first manic episode. Furthermore, a subset of patients may show premorbid cognitive abnormalities that could signal an early neurodevelopmental aetiology. Preliminary findings from small studies identify potential pro-cognitive effects of Cognitive Remediation, erythropoietin, intranasal insulin, lurasidone, mifepristone, repetitive Transcranial Magnetic Stimulation and transcranial Direct Current Stimulation in BD.

Discussion: Longitudinal studies in high-risk individuals can provide a better understanding of the development and progression of neurocognitive impairment in BD. Largescale randomised control trials are needed to compare the pro-cognitive efficacy of various pharmacological and non-pharmacological interventions in different cognitive subgroups of patients at different stages of BD.

Role of cognitive reserve in cognitive variability in euthymic individuals with bipolar disorder: cross-sectional cluster analysis

BACKGROUND

People with bipolar disorder have moderate cognitive difficulties that tend to be more pronounced during mood episodes but persist after clinical remission and affect recovery. Recent evidence suggests heterogeneity in these difficulties, but the factors underlying cognitive heterogeneity are unclear.

AIMS

To examine whether distinct cognitive profiles can be identified in a sample of euthymic individuals with bipolar disorder and examine potential differences between subgroups.

METHOD

Cognitive performance was assessed across four domains (i.e. processing speed, verbal learning/memory, working memory, executive functioning) in 80 participants. We conducted a hierarchical cluster analysis and a discriminant function analysis to identify cognitive profiles and considered differences in cognitive reserve, estimated cognitive decline from premorbid cognitive functioning, and clinical characteristics among subgroups.

RESULTS

Four discrete cognitive profiles were identified: cognitively intact (n = 25; 31.3%); selective deficits in verbal learning and memory (n = 15; 18.8%); intermediate deficits across all cognitive domains (n = 30; 37.5%); and severe deficits across all domains (n = 10; 12.5%). Cognitive decline after illness onset was greater for the intermediate and severe subgroups. Cognitive reserve scores were increasingly lower for subgroups with greater impairments. A smaller proportion of cognitively intact participants were using antipsychotic medications compared with all other subgroups.

CONCLUSIONS

Our findings suggest that individuals with cognitively impaired profiles demonstrate more cognitive decline after illness onset. Cognitive reserve may be one of the factors underlying cognitive variability across people with bipolar disorder. Patients in the intermediate and severe subgroups may be in greater need of interventions targeting cognitive difficulties.