Methodological recommendations for cognition trials in bipolar disorder by the International Society for Bipolar Disorders Targeting Cognition Task Force

Implementing cognitive screenings for outpatients with bipolar disorder following optimised treatment in a specialised mood disorder clinic

Bipolar disorder (BD) is often accompanied by persistent cognitive impairment. However, screening for cognitive impairment in the clinic is challenged by a lack of consensus on screening procedures. This study assesses cognitive impairment prevalence and screening feasibility in alignment with the International Society for Bipolar Disorder Targeting Cognition Task Force recommendations. Between January 2022 and May 2023, 136 newly diagnosed BD outpatients were assessed with the Screen for Cognitive Impairment in Psychiatry after 15-20 months of specialised care at the Copenhagen Affective Disorder Clinic. Cognitive impairment patterns and associations with cognitive complaints, perceived stress, and functioning were examined. Most screened patients (73 %) achieved full or partial remission, with 51 % being cognitively normal, 38 % showing global impairments, and 11 % displaying selective impairments. Among remitted patients, 56 % were cognitively normal, while 31 % and 13 % exhibited global or selective impairments, respectively. Both objectively impaired patient groups reported more subjective cognitive difficulties than those who were cognitively normal. The globally impaired group also demonstrated poorer functioning, more depressive symptoms and lower quality of life than cognitively normal patients. Across all patients, lower cognitive performance correlated with more cognitive complaints, lower functioning, lower quality of life, and more depressive symptoms. Cognitive screenings were relatively easily implementable, involving only a 1.5 h session including mood ratings, feedback and cognitive strategy discussion. The study highlights the clinical relevance and feasibility of cognitive screenings in BD patients, emphasizing the need for tailored interventions given frequent cognitive impairment in clinically stable individuals.

Cognition in Euthymic Patients with Bipolar Disorder: Do Not Forget to Account for Anxiety!

Purpose

Despite the high prevalence of anxiety disorders in BD and its known impact on cognitive performance, the presence and severity of anxious symptoms is not systematically evaluated in studies on cognition in BD. Our aim was to determine if attention and/or inhibition of cognitive interference in euthymic patients with type I Bipolar Disorder (BD-I) is affected by symptoms of anxiety.

Patients and Methods

Eighty-seven euthymic BD-I patients were included. Patients with comorbidities other than Generalized Anxiety Disorder (GAD) or Panic Disorder (PD) were excluded. State anxiety was measured with the Brief Inventory of Anxious Responses and Situations (ISRA-B). Subjective cognitive performance was evaluated with the COBRA scale, attention with the Digit-Span Forward task and inhibition of cognitive interference was assessed with the StroopTest interference score. Multiple linear regression models were used to test if anxious symptoms were associated with attention or inhibition of cognitive interference, considering other known contributors for cognitive impairment.

Results

Attention was unaffected by anxiety symptoms, but the overall regression for inhibition of cognitive interference was significant: years of schooling (β=1.12, p = 0.001), cognitive complaints (β=0.44, p = 0.008), and anxiety (β=-0.21, p = 0.017) explained 15% of the interference score of the Stroop test (R2 = 0.15).

Conclusion

Beyond residual affective symptoms, anxious symptoms seem to affect inhibition of cognitive interference. We recommend routine testing of anxiety when considering cognitive evaluations, especially when screening for cognitive deficits.

A systematic review of the biomarkers associated with cognition and mood state in bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a severe psychiatric disorder characterized by changes in mood that alternate between (hypo) mania or depression and mixed states, often associated with functional impairment and cognitive dysfunction. But little is known about biomarkers that contribute to the development and sustainment of cognitive deficits. The aim of this study was to review the association between neurocognition and biomarkers across different mood states.

METHOD

Search databases were Web of Science, Scopus and PubMed. A systematic review was carried out following the PRISMA guidelines. Risk of bias was assessed with the Newcastle-Ottawa Scale. Studies were selected that focused on the correlation between neuroimaging, physiological, genetic or peripheral biomarkers and cognition in at least two phases of BD: depression, (hypo)mania, euthymia or mixed. PROSPERO Registration No.: CRD42023410782.

RESULTS

A total of 1824 references were screened, identifying 1023 published articles, of which 336 were considered eligible. Only 16 provided information on the association between biomarkers and cognition in the different affective states of BD. The included studies found: (i) Differences in levels of total cholesterol and C reactive protein depending on mood state; (ii) There is no association found between cognition and peripheral biomarkers; (iii) Neuroimaging biomarkers highlighted hypoactivation of frontal areas as distinctive of acute state of BD; (iv) A deactivation failure has been reported in the ventromedial prefrontal cortex (vmPFC), potentially serving as a trait marker of BD.

CONCLUSION

Only a few recent articles have investigated biomarker-cognition associations in BD mood phases. Our findings underline that there appear to be central regions involved in BD that are observed in all mood states. However, there appear to be underlying mechanisms of cognitive dysfunction that may vary across different mood states in BD. This review highlights the importance of standardizing the data and the assessment of cognition, as well as the need for biomarkers to help prevent acute symptomatic phases of the disease, and the associated functional and cognitive impairment.

Efficacy and safety of established and off-label ADHD drug therapies for cognitive impairment or attention-deficit hyperactivity disorder symptoms in bipolar disorder: A systematic review by the ISBD Targeting Cognition Task Force

BACKGROUND

Abnormalities in dopamine and norepinephrine signaling are implicated in cognitive impairments in bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD). This systematic review by the ISBD Targeting Cognition Task Force therefore aimed to investigate the possible benefits on cognition and/or ADHD symptoms and safety of established and off-label ADHD therapies in BD.

METHODS

We included studies of ADHD medications in BD patients, which involved cognitive and/or safety measures. We followed the procedures of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed, Embase and PsycINFO from inception until June 2023. Two authors reviewed the studies independently using the Revised Cochrane Collaboration's Risk of Bias tool for Randomized trials.

RESULTS

Seventeen studies were identified (N = 2136), investigating armodafinil (k = 4, N = 1581), methylphenidate (k = 4, N = 84), bupropion (k = 4, n = 249), clonidine (k = 1, n = 70), lisdexamphetamine (k = 1, n = 25), mixed amphetamine salts (k = 1, n = 30), or modafinil (k = 2, n = 97). Three studies investigated cognition, four ADHD symptoms, and 10 the safety. Three studies found treatment-related ADHD symptom reduction: two involved methylphenidate and one amphetamine salts. One study found a trend towards pro-cognitive effects of modafinil on some cognitive domains. No increased risk of (hypo)mania was observed. Five studies had low risk of bias, eleven a moderate risk, and one a serious risk of bias.

CONCLUSIONS

Methylphenidate or mixed amphetamine salts may improve ADHD symptoms in BD. However, there is limited evidence regarding the effectiveness on cognition. The medications produced no increased mania risk when used alongside mood stabilizers. Further robust studies are needed to assess cognition in BD patients receiving psychostimulant treatment alongside mood stabilizers.

Socio-economic status, functioning and cognition in young versus adult patients newly diagnosed with bipolar disorder and their unaffected relatives; results from a cross-sectional study

BACKGROUND

Bipolar disorders (BD) figures on top of the World Health Organization classification of disabling disorders. It is unclear if there are socioeconomic, functioning, and cognition differences in young patients newly diagnosed with BD and whether these are different for young and adult patients newly diagnosed with BD. Understanding these differences is important for tailored treatment and support.

METHODS

Participant groups included 401 patients newly diagnosed with BD, 145 of their unaffected first-degree relatives (UR) and 209 healthy control individuals (HC). First, we compared socio-economic status, functioning and cognition between young patients newly diagnosed with BD (150), UR (61) and HC (92) (15-25 years) and adult patients newly diagnosed with BD (251), UR (84) and HC (117) (>25 years), respectively. Second, within patients, we compared functioning and cognition between young and adult patients newly diagnosed with BD.

RESULTS

In both participant groups, patients newly diagnosed with BD, and to a lesser degree UR, had lower socio-economic status and impaired functioning and cognition compared with HC. Further, young patients newly diagnosed with BD were less functionally impaired, than adults newly diagnosed with BD, whereas cognition did not differ between groups.

LIMITATIONS

Applied tools for assessments of functioning and cognition are not validated below age 18.

CONCLUSIONS

Overall, lower socio-economic status and impaired functioning and cognition were found both in young and adult patients newly diagnosed with BD and their UR compared with young and adult HC, respectively. Young patients were less functionally impaired than adults, but cognition was similarly impaired.

Effects of erythropoietin on cognitive impairment and prefrontal cortex activity across affective disorders: A randomized, double-blinded, placebo-controlled trial

BACKGROUND

Persistent cognitive impairment is frequent across bipolar disorder (BD) and major depressive disorder (MDD), highlighting an urgent need for pro-cognitive treatments.

AIM

This study investigated effects of erythropoietin (EPO) on cognitive impairment and dorsal prefrontal cortex (dPFC) activity in affective disorders.

METHODS

In this randomized, double-blinded, placebo-controlled trial, cognitively impaired patients with remitted BD or MDD received 1 weekly recombinant human EPO (40,000 IU/mL) or saline infusion for a 12-week period. Assessments were conducted at baseline, after 2 weeks of treatment (week 3), immediately after treatment (week 13) and at 6-months follow-up. Participants underwent functional MRI during performance on a n-back working memory (WM) task at baseline and week 3, and for a subgroup 6 weeks post-treatment (week 18). The primary outcome was a cognitive composite score at week 13, whereas secondary outcomes comprised sustained attention and functioning. WM-related dPFC activity was a tertiary outcome.

RESULTS

Data were analysed for 101 of the 103 included patients (EPO, n = 58; saline, n = 43). There were no effects of EPO over saline on any cognitive or functional outcomes or on WM-related dPFC activity.

CONCLUSIONS

The absence of treatment-related changes in cognition and neural activity was unexpected and contrasts with multiple previous preclinical and clinical studies. It is possible that the lack of effects resulted from a recent change in the manufacturing process for EPO. Nevertheless, the findings support the validity of dPFC target engagement as a biomarker model for pro-cognitive effects, according to which treatments that do not improve cognition should not modulate dPFC activity.

TRIAL REGISTRATIONS

EudraCT no.: 2016-004023-24; ClinicalTrials.gov identifier: NCT03315897.

Factors associated with the discrepancy between objective and subjective cognitive impairment in bipolar disorder

OBJECTIVE

The aim of this study is to evaluate the discrepancy between objective cognitive measures and cognitive subjective complaints in a sample of euthymic patients with bipolar disorder (BD).

METHODS

One hundred and sixteen participants (83 euthymic patients with BD and 33 healthy controls) were enrolled for this study. Patients were assessed with a comprehensive neuropsychological battery and they also reported their subjective cognitive complaints with the Cognitive Complaints in Bipolar Disorder Rating Scale (COBRA). The discrepancy between objective and subjective data was calculated using a novel methodology proposed in a previous study (Miskowiak, 2016). Statistical analyses included Pearson correlations and multiple linear regression.

RESULTS

Higher number of previous depressive episodes was identified as one variable associated with the global sensitivity composite score (Beta = 0.25; t = 2.1; p = 0.04) and with the verbal learning and memory sensitivity score (Beta = 0.26; t = 2.16; p = 0.03). That is, patients with more previous depressive episodes tend to over-report cognitive complaints. In contrast, higher number of previous hospitalizations was associated with stoicism in the global total score (Beta = -0.27; t = -2.24: p = 0.029) and in the domain of attention/processing speed (Beta = -0.34; t = -2.52; p = 0.016), indicating patients with more hospitalizations tend to report less cognitive complaints.

DISCUSSION

Our study identified some factors that might help to explain the discrepancy between objective and subjective cognitive measures in BD, including number of previous depressive episodes and number of previous hospitalizations. This highlights the need of the combined use of both types of cognitive measures to make an accurate assessment of cognitive dysfunctions and their effective treatment.

Effect of erythropoietin on cognitive side-effects of electroconvulsive therapy in depression: A randomized, double-blind, placebo-controlled trial

Electroconvulsive therapy (ECT) is one of the most effective and rapid-acting treatment for severe depression but is associated with cognitive side-effects. Identification of add-on treatments that counteract these side-effects would be very helpful. This randomized, double-blinded, placebo-controlled, parallel-group study investigated the effects of four add-on erythropoietin (EPO; 40,000 IU/ml) or saline (placebo) infusions over 2.5 weeks of ECT (eight ECT sessions) in severely depressed patients with unipolar or bipolar depression. Neuropsychological assessments were conducted pre-ECT, three days after the eighth ECT (week 4), and at a 3-month follow-up. Further, functional magnetic resonance imaging (fMRI) was conducted after the eighth ECT. The primary outcome was change from pre- to post-ECT in a 'speed of complex cognitive processing' composite. Secondary outcomes were verbal and autobiographical memory. Of sixty randomized patients, one dropped out before baseline. Data were thus analysed for 59 patients (EPO, n = 33; saline, n = 26), of whom 28 had fMRI data. No ECT-related decline occurred in the primary global cognition measure (ps≥0.1), and no effect of EPO versus saline was observed on this outcome (ps≥0.3). However post-ECT, EPO-treated patients exhibited faster autobiographical memory recall than saline-treated patients (p = 0.02), which was accompanied by lower memory-related parietal cortex activity. The absence of global cognition changes with ECT and EPO, coupled with the specific impact of EPO on autobiographical memory recall speed and memory-related parietal cortex activity, suggests that assessing autobiographical memory may provide increased sensitivity in evaluating and potentially preventing cognitive side-effects of ECT. TRIAL REGISTRATIONS: ClinicalTrials.gov: NCT03339596, EudraCT no.: 2016-002326-36.

Effect of immersive virtual reality-based cognitive remediation in patients with mood or psychosis spectrum disorders: study protocol for a randomized, controlled, double-blinded trial

BACKGROUND

Cognitive impairments are prevalent across mood disorders and psychosis spectrum disorders, but there is a lack of real-life-like cognitive training programmes. Fully immersive virtual reality has the potential to ensure motivating and engaging cognitive training directly relevant to patients' daily lives. We will examine the effect of a 4-week, intensive virtual reality-based cognitive remediation programme involving daily life challenges on cognition and daily life functioning in patients with mood disorders or psychosis spectrum disorders and explore the neuronal underpinnings of potential treatment efficacy.

METHODS

The trial has a randomized, controlled, double-blinded, parallel-group design. We will include 66 symptomatically stable outpatients with mood disorders or psychosis spectrum disorders aged 18-55 years with objective and subjective cognitive impairment. Assessments encompassing a virtual reality test of daily life cognitive skills, neuropsychological testing, measures of daily life functioning, symptom ratings, questionnaires on subjective cognitive complaints, and quality of life are carried out at baseline, after the end of 4 weeks of treatment and at a 3-month follow-up after treatment completion. Functional magnetic resonance imaging scans are performed at baseline and at the end of treatment. The primary outcome is a broad cognitive composite score comprising five subtasks on a novel ecologically valid virtual reality test of daily life cognitive functions. Two complete data sets for 54 patients will provide a power of 80% to detect a clinically relevant between-group difference in the primary outcome. Behavioural data will be analysed using linear mixed models in SPSS, while MRI data will be analysed with the FMRIB Expert Analysis Tool (FEAT). Treatment-related changes in neural activity from baseline to end of treatment will be investigated for the dorsal prefrontal cortex and hippocampus as the regions of interest.

DISCUSSION

The results will provide insight into whether virtual reality-based cognitive remediation has beneficial effects on cognition and functioning in symptomatically stable patients with mood disorders or psychosis spectrum disorders, which can aid future treatment development.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06038955. Registered on September 15, 2023.

Study protocol - elucidating the neural correlates of functional remediation for older adults with bipolar disorder

Introduction

Beyond mood abnormalities, bipolar disorder (BD) includes cognitive impairments that worsen psychosocial functioning and quality of life. These deficits are especially severe in older adults with BD (OABD), a condition expected to represent most individuals with BD in the upcoming years. Restoring the psychosocial functioning of this population will thus soon represent a public health priority. To help tackle the problem, the Bipolar and Depressive Disorders Unit at the Hospital Clínic of Barcelona has recently adapted its Functional Remediation (FR) program to that population, calling it FROA-BD. However, while scarce previous studies localize the neural mechanisms of cognitive remediation interventions in the dorsal prefrontal cortex, the specific mechanisms are seldom unknown. In the present project, we will investigate the neural correlates of FR-OABD to understand its mechanisms better and inform for potential optimization. The aim is to investigate the brain features and changes associated with FROA-BD efficacy.

Methods

Thirty-two individuals with OABD in full or partial remission will undergo a magnetic resonance imaging (MRI) session before receiving FR-OABD. After completing the FR-OABD intervention, they will undergo another MRI session. The MRI sessions will include structural, diffusion-weighted imaging (DWI), functional MRI (fMRI) with working memory (n-back) and verbal learning tasks, and frontal spectroscopy. We will correlate the pre-post change in dorsolateral and dorsomedial prefrontal cortices activation during the n-back task with the change in psychosocial functioning [measured with the Functioning Assessment Short Test (FAST)]. We will also conduct exploratory whole-brain correlation analyses between baseline or pre-post changes in MRI data and other clinical and cognitive outcomes to provide more insights into the mechanisms and explore potential brain markers that may predict a better treatment response. We will also conduct separate analyses by sex.

Discussion

The results of this study may provide insights into how FROA-BD and other cognitive remediations modulate brain function and thus could optimize these interventions.

To what extent does white matter map to cognition in bipolar disorder? A systematic review of the evidence

Cognitive impairment is a prominent feature of bipolar disorder (BD), however the neural substrates underpinning it remain unclear. Several studies have explored white matter as a correlate of cognitive functioning in BD cohorts, but mixed results and varied methodologies from one to another make inferences about this relationship difficult to draw. Here we sought to systematically synthesise the findings of these studies to more clearly explicate the nature and extent of relationships between white matter and cognition in BD and determine best practice methodologies and areas for future research in this area. Using PRISMA guidelines, we identified and systematically reviewed 37 relevant studies, all of which were cross-sectional by design. There was substantial methodological heterogeneity and variability in the clinical presentations of BD cohorts encapsulated within the studies we reviewed, which complicated our synthesis of the findings. Nonetheless, there was some evidence that cognition is related to both white matter macrostructure and microstructure in people with BD. In particular, multiple microstructural studies consistently reported that higher fractional anisotropy, both globally and in the corpus callosum, associated with better complex attention skills and executive functioning. However, several reports did not identify any associations at all, and in general, associations between WM and cognition tended to only be evident in studies utilising larger samples and post-hoc selection of WM regions of interest. Further research with increased statistical power and standardised methods are required moving forward.

Effects of intermittent theta-burst transcranial magnetic stimulation on cognition and hippocampal volumes in bipolar depression

INTRODUCTION

Repetitive transcranial magnetic stimulation (TMS) is increasingly used to treat neurocognitive symptoms in mood disorders. Intermittent theta burst stimulation (iTBS) is a brief version of TMS that may preferentially target cognitive functions. This study evaluated whether iTBS leads to cognitive improvements and associated increased hippocampal volumes in bipolar depression.

METHODS

In a two-site double-blind randomised sham controlled trial (NCT02749006), 16 patients received active iTBS to the Left Dorsolateral Prefrontal Cortex (DLPF) and 15 patients received sham stimulation across four weeks. A composite neuropsychological score and declarative memory scores served as the cognitive outcomes. Hippocampal volumes were derived from T1 weighted MRI scans using the longitudinal ComBat method to harmonise data across sites.

RESULTS

No significant improvements were observed in any cognitive variables in the active relative to the sham group; however, there was a trend for increased left hippocampal volume in the former. Left hippocampal volume increases were associated with improvements in nonverbal memory in the active group.

CONCLUSIONS

Although cognitive improvements were not associated with iTBS, the finding that hippocampal volume increases were associated with memory improvement suggests there may be some level of prefrontal-temporal neuroplasticity that could support cognitive change in future studies of iTBS in bipolar disorder.

Delivery of Neuropsychological Interventions for Adult and Older Adult Clinical Populations: An Australian Expert Working Group Clinical Guidance Paper

Delivery of neuropsychological interventions addressing the cognitive, psychological, and behavioural consequences of brain conditions is increasingly recognised as an important, if not essential, skill set for clinical neuropsychologists. It has the potential to add substantial value and impact to our role across clinical settings. However, there are numerous approaches to neuropsychological intervention, requiring different sets of skills, and with varying levels of supporting evidence across different diagnostic groups. This clinical guidance paper provides an overview of considerations and recommendations to help guide selection, delivery, and implementation of neuropsychological interventions for adults and older adults. We aimed to provide a useful source of information and guidance for clinicians, health service managers, policy-makers, educators, and researchers regarding the value and impact of such interventions. Considerations and recommendations were developed by an expert working group of neuropsychologists in Australia, based on relevant evidence and consensus opinion in consultation with members of a national clinical neuropsychology body. While the considerations and recommendations sit within the Australian context, many have international relevance. We include (i) principles important for neuropsychological intervention delivery (e.g. being based on biopsychosocial case formulation and person-centred goals); (ii) a description of clinical competencies important for effective intervention delivery; (iii) a summary of relevant evidence in three key cohorts: acquired brain injury, psychiatric disorders, and older adults, focusing on interventions with sound evidence for improving activity and participation outcomes; (iv) an overview of considerations for sustainable implementation of neuropsychological interventions as 'core business'; and finally, (v) a call to action.

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.

Associations between aberrant working memory-related neural activity and cognitive impairments in somatically healthy, remitted patients with mood disorders

BACKGROUND

Persistent cognitive deficits are prevalent in patients with bipolar disorder (BD) and unipolar disorder (UD), but treatments effectively targeting cognition in these mood disorders are lacking. This is partly due to poor insight into the neuronal underpinnings of cognitive deficits.

METHODS

The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the neuronal underpinnings of working memory (WM)-related deficits in somatically healthy, remitted patients with BD or UD (n = 66) with cognitive and functional impairments compared to 38 healthy controls (HC). The participants underwent neuropsychological testing and fMRI, while performing a visuospatial and a verbal N-back WM paradigm.

RESULTS

Relative to HC, patients exhibited hypo-activity across dorsolateral prefrontal cortex as well as frontal and parietal nodes of the cognitive control network (CCN) and hyper-activity in left orbitofrontal cortex within the default mode network (DMN) during both visuospatial and verbal WM performance. Verbal WM-related response in the left posterior superior frontal gyrus (SFG) within CCN was lower in patients and correlated positively with out-of-scanner executive function performance across all participants.

CONCLUSIONS

Our findings suggest that cognitive impairments across BD and UD are associated with insufficient recruitment of task-relevant regions in the CCN and down-regulation of task-irrelevant orbitofrontal activity within the DMN during task performance. Specifically, a lower recruitment of the left posterior SFG within CCN during verbal WM was associated with lower cognitive performance.

If you feel you can't, you won't: the role of subjective and objective cognitive competence on psychosocial functioning in depression

BACKGROUND

The purpose of this exploratory study is to examine the role of sociodemographic, clinical, and cognitive - both objective and subjective - factors in overall and in specific domains of psychosocial functioning, in patients with depression at different clinical states of the disease (remitted and non-remitted).

METHODS

A sample of 325 patients with major depressive disorder, 117 in remission and 208 in non-remission, were assessed with a semi-structured interview collecting sociodemographic, clinical, cognitive (with neuropsychological tests and the Perceived Deficit Questionnaire), and functional (Functioning Assessment Short Test) characteristics. Backward regression models were conducted to determine associations of global and specific areas of functioning with independent factors, for both clinical states.

RESULTS

Residual depressive symptomatology and self-appraisal of executive competence were significantly associated with psychosocial functioning in remitted patients, in overall and some subdomains of functioning, particularly cognitive and interpersonal areas. While depressive symptoms, executive deficits and self-appraisal of executive function were significantly related to functional outcomes in non-remitted patients, both in overall functioning and in most of subdomains.

DISCUSSION

This study evidences the strong association of one's appraisal of executive competence with psychosocial functioning, together with depressive symptoms, both in remitted and non-remitted patients with depression. Therefore, to achieve full recovery, clinical management of patients should tackle not only the relief of core depressive symptoms, but also the cognitive ones, both those that are objectified with neuropsychological tests and those that are reported by the patients themselves.

Cognition in Bipolar Disorder: An Update for Clinicians

Bipolar disorder is associated with cognitive deficits, which persist across mood states and affect functional outcomes. This article provides an overview of recent progress in measuring cognition in bipolar disorder and its implications for both research and clinical practice. The authors summarize work conducted over the past decade that has helped guide researchers and clinicians in the appropriate measurement of cognitive functioning in bipolar disorder, the design of research studies targeting this domain for treatment, and the implementation of screening and psychoeducational tools in the clinic. Much of this work was conducted by the International Society for Bipolar Disorders Targeting Cognition Task Force. Here, the authors also highlight the need for clinicians to be informed about this aspect of illness and to be equipped with the necessary information to assess, track, and intervene on cognitive problems when appropriate. Finally, the article identifies gaps in the literature and suggests potential future directions for research in this area.

Functioning in older adults with bipolar disorder: A report on recommendations by the International Society of bipolar disorder (ISBD) older adults with bipolar disorder (OABD) task force

OBJECTIVES

Despite the importance of psychosocial functioning impairment in Bipolar Disorder (BD), its role among Older Adults with BD (OABD) is not well known. The development of guidelines for the assessment of psychosocial functioning helps to facilitate a better understanding of OABD and can lead to better tailored interventions to improve the clinical outcomes of this population.

METHODS

Through a series of virtual meetings, experts from eight countries in the International Society of Bipolar Disorder (ISBD) on OABD task force developed recommendations for the assessment of psychosocial functioning.

RESULTS

We present (1) a conceptualization of functioning in OABD and differences compared with younger patients; (2) factors related to functioning in OABD; (3) current measures of functioning in OABD and their strengths and limitations; and, (4) other potential sources of information to assess functioning.

CONCLUSIONS

The task force created recommendations for assessing functioning in OABD. Current instruments are limited, so measures specifically designed for OABD, such as the validated FAST-O scale, should be more widely adopted. Following the proposed recommendations for assessment can improve research and clinical care in OABD and potentially lead to better treatment outcomes.

Long-term outcomes of an internet-delivered cognitive enhancement intervention targeting residual cognitive deficits after major depressive disorder: a 2-year follow-up of an open trial

Background

Cognitive deficits are common and disabling residual symptoms following major depressive disorder (MDD) and are related to increased risk of relapse. Residual cognitive deficits should thus be considered an important target for treatment. However, few have reported long-term outcomes of interventions targeting residual cognitive deficits.

Objective

This study aimed to (1) investigate change between pre-treatment and 2-year follow-up assessments in cognitive deficits, rumination, and symptoms of MDD after an internet-delivered intervention targeting residual cognitive deficits; (2) to investigate stability in outcomes between 6-month and 2-year follow-up assessments; (3) to report the number of participants' experiencing a new episode of MDD in the follow-up period; and (4) to investigate differences in outcomes between those who experienced a new episode of MDD and those who did not.

Methods

A total of 43 partly remitted adults were included to test a guided internet-delivered intervention, which consisted of 10 modules involving psychoeducation, cognitive strategies, and attention training. Participants were assessed at pre-treatment, post-treatment, after 6-months, and after 2-years, with measures assessing self-reported residual cognitive deficits, rumination, symptoms of MDD and relapse. Overall, 32 participants completed the 2-year follow-up assessment.

Results

Between the pre-treatment and 2-year follow-up assessments, there was a reduction in cognitive deficits and rumination, while there was an increase in symptoms of MDD. Cognitive deficits were stable between the 6-month and the 2-year follow-up, while there was an increase in rumination and symptoms of MDD. Thirteen of 32 participants reported a new episode of MDD during the follow-up period. The relapse group reported longer duration of MDD at pre-treatment and showed a difference in all outcomes after 2 years compared to the no-relapse group. The no-relapse group showed improvement in MDD symptoms at post-treatment, while the relapse group did not.

Conclusion

Delivering cognitive enhancement interventions over the internet is potentially related to stable improvements in residual cognitive deficits. The effects on rumination and symptoms of MDD are less certain. Lack of improvement in MDD symptoms after the intervention period should be investigated as an indicator of relapse. Results should be interpreted with caution due to the lack of control group and sample size.

Brain atrophy and cognitive decline in bipolar disorder: Influence of medication use, symptomatology and illness duration

Bipolar disorder (BPD) is a chronic condition characterized by recurrent episodes of mania and depression. To date, the association of biological and psychopathological processes in BPD has not been extensively studied on a cognitive and cortical basis at the same time. We investigated whether brain atrophy (in prefrontal, temporal and occipital cortices) was associated with cognitive, biological and clinical processes in patients with BPD and healthy controls (HCs). A total of 104 participants (56 with BPD) completed tasks that measured attention, memory, information processing speed, inhibitory control, visuospatial working memory and cognitive flexibility. In addition, structural brain scans were obtained using high-resolution MRI. Outcomes of the measurements were examined using robust multiple mediation analyses. BPD patients showed greater cortical atrophy across all regions of interest when compared to HCs, linked to cognitive decline. BPD patients had slower reaction times and markedly increased errors of commission on the tasks. The outcomes were significantly influenced by medication use, symptomatology and illness duration. The findings showcase the complexity of brain structures and networks as well as the physiological mechanisms underlying diverse BPD symptomatology and endophenotypes. These differences were pronounced in patients with BPD, motivating further investigations of pathophysiological mechanisms involved in brain atrophy and cognitive decline.

Improvement in self-reported cognitive functioning but not in rumination following online working memory training in a two-year follow-up study of remitted major depressive disorder

Self-reported subjective cognitive difficulties (subjective deficits) and rumination are central residual cognitive symptoms following major depressive disorder (MDD). These are risk factors for more a severe course of illness, and despite the considerable relapse risk of MDD, few interventions target the remitted phase, a high-risk period for developing new episodes. Online distribution of interventions could help close this gap. Computerized working memory training (CWMT) shows promising results, but findings are inconclusive regarding which symptoms improve following this intervention, and its long-term effects. This study reports results from a longitudinal open-label two-year follow-up pilot-study of self-reported cognitive residual symptoms following 25 sessions (40 min), five times a week of a digitally delivered CWMT intervention. Ten of 29 patients remitted from MDD completed two-year follow-up assessment. Significant large improvements in self-reported cognitive functioning on the behavior rating inventory of executive function-adult version appeared after two-years (d = 0.98), but no significant improvements were found in rumination (d < 0.308) measured by the ruminative responses scale. The former showed moderate non-significant associations to improvement in CWMT both post-intervention (r = 0.575) and at two-year follow-up (r = 0.308). Strengths in the study included a comprehensive intervention and long follow-up time. Limitations were small sample and no control group. No significant differences between completers and drop-outs were found, however, attrition effects cannot be ruled out and demand characteristics could influence findings. Results suggested lasting improvements in self-reported cognitive functioning following online CWMT. Controlled studies with larger samples should replicate these promising preliminary findings.

Association of childhood trauma with cognitive impairment and structural brain alterations in remitted patients with bipolar disorder

BACKGROUND

Cognitive impairment affects many patients with bipolar disorder (BD). No pro-cognitive treatment with robust efficacy exists partly due to limited insight into underlying neurobiological abnormalities.

METHODS

This magnetic resonance imaging (MRI) study investigates structural neuronal correlates of cognitive impairment in BD by comparing brain measures in a large sample of cognitively impaired versus cognitively intact patients with BD or cognitively impaired patients with major depressive disorder (MDD) and healthy controls (HC). Participants underwent neuropsychological assessments and MRI scans. The cognitively impaired and - intact BD and MDD patient groups were compared with each other and HC regarding prefrontal cortex measures, hippocampus shape/volume, and total cerebral white (WM) and grey matter (GM).

RESULTS

Cognitively impaired BD patients showed lower total cerebral WM volume than HC, which scaled with poorer global cognitive performance and more childhood trauma. Cognitively impaired BD patients also showed lower adjusted GM volume and thickness in the frontopolar cortex than HC but greater adjusted GM volume in the temporal cortex than cognitively normal BD patients. Cognitively impaired BD patients showed decreased cingulate volume than cognitively impaired MDD patients. Hippocampal measures were similar across all groups.

LIMITATIONS

The cross-sectional study design prevented insights into causal relationships.

CONCLUSIONS

Lower total cerebral WM and regional frontopolar and temporal GM abnormalities may constitute structural neuronal correlates of cognitive impairment in BD, of which the WM deficits scale with the degree of childhood trauma. The results deepen the understanding of cognitive impairment in BD and provide a neuronal target for pro-cognitive treatment development.

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.

Association of neurocognitive function with psychiatric hospitalization and socio-demographic conditions in individuals with bipolar and major depressive disorders

Background

Neurocognitive impairments are associated with poor clinical and employment outcomes in individuals with affective disorders. However, little is known about their associations with long-term clinical outcomes such as psychiatric hospitalizations, and with socio-demographic indicators other than employment. In the largest longitudinal study of neurocognition in affective disorders to date, we investigate the role of neurocognitive impairments on psychiatric hospitalizations and socio-demographic conditions.

Methods

The study included 518 individuals with bipolar or major depressive disorder. Neurocognitive assessments covered executive function and verbal memory domains. Longitudinal data on psychiatric hospitalization and socio-demographic conditions (employment, cohabitation, and marital status) for up to 11 years were obtained using National population-based registers. The primary and secondary outcomes were psychiatric hospitalizations (n = 398) and worsening of socio-demographic conditions (n = 518), in the follow-up period since study inclusion, respectively. Cox regression models were used to examine the association of neurocognition with future psychiatric hospitalizations and the worsening of socio-demographic conditions.

Findings

Clinically significant impairment in verbal memory (z-score ≤ -1; defined by the ISBD Cognition Task Force), but not in executive function, was associated with a higher risk of future hospitalization, when adjusted for age, sex, hospitalization in the year preceding inclusion, depression severity, diagnosis, and type of clinical trial (HR = 1.84, 95% CI:1.05-3.25, p = 0.034; n = 398). The results remained significant even after accounting for illness duration. Neurocognitive impairments were not associated with the worsening of socio-demographic conditions (p ≥ 0.17; n = 518).

Interpretation

Promoting neurocognitive function, especially verbal memory, may mitigate the risk of future psychiatric hospitalization in individuals with affective disorders.

Funding

Lundbeckfonden (R279-2018-1145).

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.

The mediating role of depressive symptoms and subjective cognitive dysfunction in the relationship between stressful life events and functional disability in adult community volunteers

BACKGROUND

Stressful life events (SLE) impact psychosocial functioning. However, the psychological mechanism underlying the association between SLE and functional disability (FD) has not been fully elucidated. This study focused on whether depressive symptoms (DS) and subjective cognitive dysfunction (SCD) mediated the influence of SLE, comprising negative SLE (NSLE) and positive SLE (PSLE), on FD.

METHODS

A total of 514 adults from Tokyo, Japan, completed the self-administered questionnaires to evaluate DS, SCD, SLE, and FD. We investigated the relationships among the variables using path analysis.

RESULTS

Path analyses showed that NSLE positively affected FD directly (β = 0.253, p < .001), and indirectly via DS and SCD (β = 0.192, p < .001). PSLE negatively affected FD indirectly via DS and SCD (β = -0.068, p = .010), although PSLE did not affect FD directly (β = -0.049, p = .163).

LIMITATIONS

Causal relationships could not be determined owing to the cross-sectional design. All participants were recruited in Japan, which limits the generalization of findings to other countries.

CONCLUSIONS

DS and SCD, in this order, may partially mediate the positive effect of NSLE on FD. DS and SCD may fully mediate the negative effect of PSLE on FD. When considering the impact of SLE on FD, evaluating the mediating role of DS and SCD could be useful. Our findings may elucidate how perceived life stress affects daily functioning via depressive and cognitive symptoms. In the future, it is desirable to conduct a longitudinal study based on our results.

Psychometric Properties of the Korean Version of Functioning Assessment Short Test in Bipolar Disorder

Objective

The Functioning Assessment Short Test (FAST) is a relatively specific test for bipolar disorders designed to assess the main functioning problems experienced by patients. This brief instrument includes 24 items assessing impairment or disability in 6 domains of functioning: autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships, and leisure time. It has already been translated into standardized versions in several languages. The aim of this study is to measure the validity and reliability of the Korean version of FAST (K-FAST).

Methods

A total of 209 bipolar disorder patients were recruited from 14 centers in Korea. K-FAST, Young Mania Rating Scale (YMRS), Bipolar Depression Rating Scale (BDRS), Global Assessment of Functioning (GAF) and the World Health Organization Quality of Life Assessment Instrument Brief Form (WHOQOL-BREF) were administered, and psychometric analysis of the K-FAST was conducted.

Results

The internal consistency (Cronbach's alpha) of the K-FAST was 0.95. Test-retest reliability analysis showed a strong correlation between the two measures assessed at a 1-week interval (ICC = 0.97; p < 0.001). The K-FAST exhibited significant correlations with GAF (r = -0.771), WHOQOL-BREF (r = -0.326), YMRS (r = 0.509) and BDRS (r = 0.598). A strong negative correlation with GAF pointed to a reasonable degree of concurrent validity. Although the exploratory factor analysis showed four factors, the confirmatory factor analysis of questionnaires had a good fit for a six factors model (CFI = 0.925; TLI = 0.912; RMSEA = 0.078).

Conclusion

The K-FAST has good psychometric properties, good internal consistency, and can be applicable and acceptable to the Korean context.

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.

A self-administered immersive virtual reality tool for assessing cognitive impairment in patients with cancer

Objective

This study was aimed at exploring the feasibility and validity of a self-administered immersive virtual reality (VR) tool designed to assess cognitive impairment in patients with cancer.

Methods

In a cross-sectional survey study, an immersive tool was used to rate the previously recommended core assessment domains of cancer-related cognitive impairment-comprising attention, verbal learning memory, processing speed, executive function and verbal fluency-via an interactive VR scenario.

Results

A total of 165 patients with cancer participated in this study. The participants' mean age was 47.74 years (SD ​= ​10.59). Common cancer types included lung, liver, breast and colorectal cancer, and most patients were in early disease stages (n ​= ​146, 88.5%). Participants' performance in the VR cognition assessment showed a moderate to strong positive correlation with their paper-and-pencil neurocognitive test results (r ​= ​0.34-0.76, P ​< ​0.001), thus indicating high concurrent validity of the immersive VR cognition assessment tool. For all participants, the mean score for the VR-based cognition assessment was 5.41 (SD ​= ​0.70) out of a potential maximum of 7.0. The mean simulation sickness score for the VR-based tool, as rated by the patients, was 0.35 (SD ​= ​0.19), thereby indicating that minimal simulation sickness occurred during the VR-assisted cognition assessment.

Conclusions

Given its demonstrated validity, and the patients' high presence scores and minimal sickness scores, this VR-based cognition assessment tool is a feasible and acceptable instrument for measuring cognitive impairment in patients with cancer. However, further psychometric assessments should be implemented in clinical settings.

The trajectory of emotional and non-emotional cognitive function in newly diagnosed patients with bipolar disorder and their unaffected relatives: A 16-month follow-up study

Cognitive impairments are evident in remitted patients with bipolar disorder (BD) and their unaffected relatives (UR) compared to healthy controls (HC). However, the temporal course of cognition, and whether cognition is marked by neuroprogressive changes, remain unclear. In a large prospective study of newly diagnosed patients with BD, we assessed patients with BD (n = 266), UR (n = 105) and HC (n = 190) using an extensive cognitive battery of non-emotional and emotional cognition at baseline and 16-months follow-up. Cognitive change across groups was examined with linear mixed-model analyses. Results showed no evidence of trajectory differences between patients with BD, UR, and HC in neurocognition and emotional cognition (ps≥.10). Patients with BD showed stable impairments in global neurocognitive functioning over time, as well as within the domains of 'working memory and executive function' and 'attention and psychomotor speed', compared to HC. Patients who relapsed during the follow-up time were less successful at down-regulating emotions in positive social scenarios compared to HC. Unaffected relatives also displayed stable deficits in 'working memory and executive function' over time, with performance at intermediate levels between BD probands and HC. Finally, poorer neurocognition and positive emotion regulation were associated with more subsyndromal symptoms and functional impairments. In conclusion, we found no evidence of a neuroprogressive origin of cognitive impairments in the newly diagnosed BD or in their UR. Patients' and UR's impairments in working memory and executive function may reflect a stable cognitive trait-marker of familial risk. Difficulties with positive emotion regulation may be associated with illness progression in BD.

Can circadian rhythm predict changes in neurocognitive functioning in bipolar disorder: protocol of a 12-month longitudinal cohort study based on research domain criteria

Introduction: Bipolar disorder (BD) is a prevalent and disabling mental disorder characterized by disrupted circadian rhythms and impaired neurocognitive features, both of which fall under the major domains of Research Domain Criteria (RDoC). However, there is limited evidence regarding the interaction between circadian rhythms and long-term neurocognitive functioning. Therefore, this longitudinal cohort study protocol aims to explore whether circadian rhythm can predict changes in neurocognitive functioning over time in patients with BD.Methods: This study adopts a longitudinal cohort design, aiming to recruit 100 BD patients in either depressive or remitted states. Participants will undergo evaluations from clinical, circadian rhythm, and neurocognitive perspectives at baseline, 6-month, and 12-month follow-ups, involving questionnaires, actigraphy, and computed neurocognitive tests. We will examine both cross-sectional and longitudinal associations between participants' circadian rhythm patterns and neurocognitive functioning. Statistical analyses will employ Spearman correlation and mixed regression models.Discussion: We anticipate that circadian rhythms may serve as predictors of neurocognitive functioning changes. The findings of this study could offer supplementary insights into BD pathophysiology, potential treatment targets, and prediction.Trial Registration: This study has been registered with the Chinese Clinical Trial Registry under the registration code ChiCTR2200064922 on 21st October 2022.

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.

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.

The clinical characterization of the adult patient with bipolar disorder aimed at personalization of management

Bipolar disorder is heterogeneous in phenomenology, illness trajectory, and response to treatment. Despite evidence for the efficacy of multimodal-ity interventions, the majority of persons affected by this disorder do not achieve and sustain full syndromal recovery. It is eagerly anticipated that combining datasets across various information sources (e.g., hierarchical "multi-omic" measures, electronic health records), analyzed using advanced computational methods (e.g., machine learning), will inform future diagnosis and treatment selection. In the interim, identifying clinically meaningful subgroups of persons with the disorder having differential response to specific treatments at point-of-care is an empirical priority. This paper endeavours to synthesize salient domains in the clinical characterization of the adult patient with bipolar disorder, with the overarching aim to improve health outcomes by informing patient management and treatment considerations. Extant data indicate that characterizing select domains in bipolar disorder provides actionable information and guides shared decision making. For example, it is robustly established that the presence of mixed features - especially during depressive episodes - and of physical and psychiatric comorbidities informs illness trajectory, response to treatment, and suicide risk. In addition, early environmental exposures (e.g., sexual and physical abuse, emotional neglect) are highly associated with more complicated illness presentations, inviting the need for developmentally-oriented and integrated treatment approaches. There have been significant advances in validating subtypes of bipolar disorder (e.g., bipolar I vs. II disorder), particularly in regard to pharmacological interventions. As with other severe mental disorders, social functioning, interpersonal/family relationships and internalized stigma are domains highly relevant to relapse risk, health outcomes, and quality of life. The elevated standardized mortality ratio for completed suicide and suicidal behaviour in bipolar disorder invites the need for characterization of this domain in all patients. The framework of this paper is to describe all the above salient domains, providing a synthesis of extant literature and recommendations for decision support tools and clinical metrics that can be implemented at point-of-care.

Can magnetic resonance imaging enhance the assessment of potential new treatments for cognitive impairment in mood disorders? A systematic review and position paper by the International Society for Bipolar Disorders Targeting Cognition Task Force

BACKGROUND

Developing treatments for cognitive impairment is key to improving the functioning of people with mood disorders. Neuroimaging may assist in identifying brain-based efficacy markers. This systematic review and position paper by the International Society for Bipolar Disorders Targeting Cognition Task Force examines the evidence from neuroimaging studies of pro-cognitive interventions.

METHODS

We included magnetic resonance imaging (MRI) studies of candidate interventions in people with mood disorders or healthy individuals, following the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis 2020 statement. Searches were conducted on PubMed/MEDLINE, PsycInfo, EMBASE, Cochrane Library, and Clinicaltrials.gov from inception to 30th April 2021. Two independent authors reviewed the studies using the National Heart, Lung, Blood Institutes of Health Quality Assessment Tool for Controlled Intervention Studies and the quality of neuroimaging methodology assessment checklist.

RESULTS

We identified 26 studies (N = 702). Six investigated cognitive remediation or pharmacological treatments in mood disorders (N = 190). In healthy individuals, 14 studies investigated pharmacological interventions (N = 319), 2 cognitive training (N = 73) and 4 neuromodulatory treatments (N = 120). Methodologies were mostly rated as 'fair'. 77% of studies investigated effects with task-based fMRI. Findings varied but most consistently involved treatment-associated cognitive control network (CCN) activity increases with cognitive improvements, or CCN activity decreases with no cognitive change, and increased functional connectivity. In mood disorders, treatment-related default mode network suppression occurred.

CONCLUSIONS

Modulation of CCN and DMN activity is a putative efficacy biomarker. Methodological recommendations are to pre-declare intended analyses and use task-based fMRI, paradigms probing the CCN, longitudinal assessments, mock scanning, and out-of-scanner tests.

Social cognition and bipolar disorder: pending questions and unexplored topics

Social cognition has gained prominence in psychiatric research, beginning with schizophrenia and more recently in bipolar disorder. Considering the relevance of this domain to interpersonal relationships and functionality, we aimed to explore the fundamental research and clinical issues regarding social cognition and discuss future directions and challenges in the field of bipolar disorder.

Cognitive factor structure and measurement invariance between healthy controls and patients with major depressive disorder

Cognitive impairments are crucial in functional outcomes of major depressive disorder (MDD). The effectiveness of currently available treatment methods for cognitive deficits is suboptimal. A cognitive test battery is often applied to evaluate cognition with multiple interrelated and difficult-to-interpret outcomes. Generating cognitive factor scores after the confirmation of a common cognitive structure and measurement invariance between healthy controls (HCs) and patients may aid in understanding cognition further. This methodology has been applied for several neuropsychiatric disorders, but not for MDD. Therefore, we conducted a series of exploratory factor analyses (EFA), confirmatory factor analyses (CFA), and multiple groups CFA (MGCFA) for a cognitive test battery in HCs and patients with MDD. The initial EFA of 106 HCs yielded a three-factor model-comprising attention, memory, and executive function. The CFA confirmed the initial model in other 94 HCs with revisions, which reasonably fit the cognitive data of 54 patients with MDD. MGCFA supported the measurement invariance of the determined model between HCs and patients with MDD. The associations of cognitive factor scores with age or education and the effect sizes of group differences in cognitive factor scores externally validated the determined model. In conclusion, this is the first study to demonstrate the measurement invariance of a cognitive model between HCs and patients with MDD using MGCFA. The measurement invariance substantiated valid group comparisons of factor scores and their relationships with other markers. The current results may be applicable for the development of improved treatment strategies for cognitive impairments in MDD.

Neuropsychological aspects of bipolar disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and aprevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in this review.

The Role of Kynurenines in Cognitive Dysfunction in Bipolar Disorder

INTRODUCTION

Chronic low-grade inflammation is suggested to play a pathophysiological role in bipolar disorder (BD) and its related cognitive dysfunctions. Although kynurenine (KYN) pathway metabolites are key inflammatory mediators, studies investigating the association between KYN metabolism and cognition in BD are scarce. We aimed to explore the relationship between KYN metabolism and cognitive functioning across different mood states in BD.

METHODS

Sixty-seven patients with BD (35 depressed and 32 [hypo] manic) and 29 healthy controls were included. Cognitive functioning was assessed at 3 time intervals (baseline, 4, and 8 months) assessing processing speed, sustained attention, verbal memory, working memory, and response inhibition. Plasma samples for quantification of 3-hydroxykynurenine, quinolinic acid, and kynurenic acid (KYNA) were concurrently provided. Linear mixed models were used for statistical analysis.

RESULTS

The manic group showed deficits in all assessed cognitive domains with the exception of verbal memory at all test moments. The bipolar depression group showed deficits in the processing speed at all test moments. Throughout the whole follow-up period, KYNA was significantly lower in both patient groups than in controls. Only in the bipolar depression group, low KYNA was associated with worse global cognitive functioning (B = 0.114, p = 0.02) and slower processing speed in particular (B = 0.139, p = 0.03).

CONCLUSION

Only in the bipolar depression group, lower KYNA was associated with worse cognitive functioning. Future large-scale longitudinal studies are warranted to confirm the role of KYN metabolites in cognitive impairment in patients with BD and the possible therapeutic implications of this relationship.

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.

Bipolar disorder treatment according to illness trajectory: a systematic review of clinical trials

The current bipolar disorder treatment guidelines focus mainly on the prevention of recurrence and stabilization of acute mood episodes while neglecting outcomes related to the longitudinal course of illness. We systematically reviewed studies that assess the impact of disease progression in the treatment of patients with bipolar disorder. We searched PubMed, Embase, and Web of Science for clinical trials that moderated treatment effects by number of previous episodes, disease length, or a clinical staging model. We retrieved 6,156 potential abstracts. After deduplication, 5,376 were screened and eight studies met inclusion criteria. Seven trials moderated results by number of prior episodes, and one of those also used a measure of disease length. One trial used a clinical staging model and yielded informing results. Only three studies evaluated pharmacological interventions, the other five assessing psychotherapeutic modalities. Most of the studies were post-hoc analysis of clinical trials not primarily aimed at studying variables associated with illness trajectory. Overall, a loss of efficacy was found according to clinical progression, which supports early intervention. Tailored recommendations according to disease stages cannot be made. Furthermore, we identified methodological weaknesses and strengths in this subfield of research, suggesting the use of clinical staging models for future studies.

Cognitive complaints mediate the influence of sleep disturbance and state anxiety on subjective well-being and ill-being in adult community volunteers: a cross sectional study

Background

Sleep disturbance, state anxiety, and cognitive complaints (CCs) have been recognized as important issues in public health. Although the mediating role of CCs has been proposed, their role in the relationships between sleep disturbance, state anxiety, and subjective well-being (SWB) and subjective ill-being (SIB) are not yet fully understood. This study used path analyses to investigate whether CCs mediate these relationships.

Methods

The study recruited 523 Japanese adult volunteers using convenience sampling. Participants completed the Pittsburgh Sleep Quality Index, State–Trait Anxiety Inventory (Form Y), Cognitive Complaints in Bipolar Disorder Rating Assessment, and Subjective Well-Being Inventory to evaluate sleep disturbance, state anxiety, CCs, and SWB and SIB, respectively. Path analyses were conducted to assess the mediating effects of CCs.

Results

The path analyses showed significant indirect associations of sleep disturbance and state anxiety with SWB (p = 0.024 and p = 0.012) and SIB (p < 0.001 and p < 0.001), respectively, mediated by CCs. Furthermore, there were significant indirect associations of sleep disturbance with CCs (p < 0.001), SWB (p < 0.001), and SIB (p < 0.001), via state anxiety, respectively.

Conclusions

This study suggests that CCs mediate the associations of sleep disturbance and state anxiety with SWB and SIB, respectively, in adult community volunteers. To address SWB and SIB associated with sleep disturbance and state anxiety, evaluating CCs may be useful in public mental health. Our findings will encourage health care workers to assess CCs more systematically. Future studies may need to target CCs to develop interventions for SWB and SIB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12936-0.

The relations between executive functions and occupational functioning in individuals with bipolar disorder: a scoping review

Background

Patients with bipolar disorder experience impairments in their occupational functioning, despite remission of symptoms. Previous research has shown that neurocognitive deficits, especially deficits in executive functions, may persist during euthymia and are associated with diminished occupational functioning.

Objectives

The aim of this scoping review was to identify published studies that report on the relationships between executive functions and occupational functioning in BD to review current knowledge and identify knowledge gaps. In addition to traditional neuropsychological approaches, we aimed to describe executive functioning from a self-regulation perspective, including emotion regulation.

Methods

We applied the methodological framework as described by Arksey and O’Malley (Int J Soc Res Methodol Theory Pract 8:19–32, 2005) and Levac et al. (Implement Sci 5:1–9, 2010). We searched PubMed and psycINFO for literature up to November 2021, after which we screened papers based on inclusion criteria. Two reviewers independently performed the screening process, data charting process, and synthesis of results.

Results

The search yielded 1202 references after deduplication, of which 222 remained after initial screening. The screening and inclusion process yielded 82 eligible papers in which relationships between executive functions and occupational functioning are examined.

Conclusion

Neurocognitive deficits, including in executive functions and self-regulation, are associated with and predictive of diminished occupational functioning. Definitions and measurements for neurocognitive functions and occupational functioning differ greatly between studies, which complicates comparisons. Studies on functional remediation show promising results for improving occupational functioning in patients with BD. In research and clinical practice more attention is needed towards the quality of work functioning and the various contexts in which patients with BD experience deficits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40345-022-00255-7.

Influence of pre-treatment structural brain measures on effects of action-based cognitive remediation on executive function in partially or fully remitted patients with bipolar disorder

Cognitive impairment is an emerging treatment target in patients with bipolar disorder (BD) but so far, no evidence-based treatment options are available. Recent studies indicate promising effects of Cognitive Remediation (CR) interventions, but it is unclear who responds most to these interventions. This report aimed to investigate whether pre-treatment dorsal prefrontal cortex (dPFC) thickness predicts improvement of executive function in response to Action-Based Cognitive Remediation (ABCR) in patients with BD. Complete baseline magnetic resonance imaging (MRI) data were available from 45 partially or fully remitted patients with BD from our randomized controlled ABCR trial (ABCR: n = 25, control group: n = 20). We performed cortical reconstruction and volumetric segmentation using FreeSurfer. Multiple linear regression analysis was conducted to assess the influence of dPFC thickness on ABCR-related executive function improvement, reflected by change in the One Touch Stocking of Cambridge performance from baseline to post-treatment. We also conducted whole brain vertex wise analysis for exploratory purposes. Groups were well-matched for demographic and clinical variables. Less pre-treatment dPFC thickness was associated with greater effect of ABCR on executive function (p = 0.02). Further, whole-brain vertex analysis revealed an association between smaller pre-treatment superior temporal gyrus volume and greater ABCR-related executive function improvement. The observed associations suggest that structural abnormalities in dPFC and superior temporal gyrus are key neurocircuitry treatment targets for CR interventions that target impaired executive function in BD.

Fatigue and cognitive impairment in Post-COVID-19 Syndrome: A systematic review and meta-analysis

IMPORTANCE

COVID-19 is associated with clinically significant symptoms despite resolution of the acute infection (i.e., post-COVID-19 syndrome). Fatigue and cognitive impairment are amongst the most common and debilitating symptoms of post-COVID-19 syndrome.

OBJECTIVE

To quantify the proportion of individuals experiencing fatigue and cognitive impairment 12 or more weeks following COVID-19 diagnosis, and to characterize the inflammatory correlates and functional consequences of post-COVID-19 syndrome.

DATA SOURCES

Systematic searches were conducted without language restrictions from database inception to June 8, 2021 on PubMed/MEDLINE, The Cochrane Library, PsycInfo, Embase, Web of Science, Google/Google Scholar, and select reference lists.

STUDY SELECTION

Primary research articles which evaluated individuals at least 12 weeks after confirmed COVID-19 diagnosis and specifically reported on fatigue, cognitive impairment, inflammatory parameters, and/or functional outcomes were selected.

DATA EXTRACTION & SYNTHESIS

Two reviewers independently extracted published summary data and assessed methodological quality and risk of bias. A meta-analysis of proportions was conducted to pool Freeman-Tukey double arcsine transformed proportions using the random-effects restricted maximum-likelihood model.

MAIN OUTCOMES & MEASURES

The co-primary outcomes were the proportions of individuals reporting fatigue and cognitive impairment, respectively, 12 or more weeks following COVID-19 infection. The secondary outcomes were inflammatory correlates and functional consequences associated with post-COVID-19 syndrome.

RESULTS

The literature search yielded 10,979 studies, and 81 studies were selected for inclusion. The fatigue meta-analysis comprised 68 studies, the cognitive impairment meta-analysis comprised 43 studies, and 48 studies were included in the narrative synthesis. Meta-analysis revealed that the proportion of individuals experiencing fatigue 12 or more weeks following COVID-19 diagnosis was 0.32 (95% CI, 0.27, 0.37; p < 0.001; n = 25,268; I² = 99.1%). The proportion of individuals exhibiting cognitive impairment was 0.22 (95% CI, 0.17, 0.28; p < 0.001; n = 13,232; I² = 98.0). Moreover, narrative synthesis revealed elevations in proinflammatory markers and considerable functional impairment in a subset of individuals.

CONCLUSIONS & RELEVANCE

A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19. The frequency and debilitating nature of the foregoing symptoms provides the impetus to characterize the underlying neurobiological substrates and how to best treat these phenomena.

STUDY REGISTRATION

PROSPERO (CRD42021256965).

Cognitive Adverse Effects of Electroconvulsive Therapy: A Discrepancy Between Subjective and Objective Measures?

OBJECTIVES

The character and duration of cognitive adverse effects of electroconvulsive therapy (ECT) are unclear. This study investigated (1) the sensitivity of a short cognitive test battery to cognitive adverse effects of ECT, (2) the relation between subjective and objective cognitive adverse effects, and (3) patient characteristics associated with more subjective than objective adverse effects.

METHODS

Forty-one patients with unipolar or bipolar depression referred to ECT underwent assessments at baseline, 5 to 7 days post-ECT, and 3 months post-ECT. Patients rated their fear of various aspects of ECT on a visual analog scale. At each assessment, patients were evaluated for depressive symptoms, completed the Screen for Cognitive Impairment in Psychiatry (SCIP) and Trail Making Test-Part B (TMT-B), and rated their cognitive difficulties.

RESULTS

Patients feared cognitive adverse effects and lack of treatment efficacy more than other aspects of ECT. The SCIP and TMT-B revealed transient decline in objective cognition after ECT, which was reversed after 3 months. Patients presented with more subjective than objective cognitive difficulties at baseline and more subjective than objective cognitive adverse effects of ECT. This discrepancy was significantly reduced at follow-up. Younger age and poorer objective cognition pretreatment were associated with more subjective than objective cognitive adverse effects 5 to 7 days after ECT.

CONCLUSIONS

The SCIP and TMT-B are sensitive to cognitive adverse effects of ECT. Patients show more subjective than objective cognitive adverse effects of ECT. These insights can be used clinically to inform patients of treatment choice and expected cognitive consequences.

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.

Neuronal underpinnings of cognitive impairment in bipolar disorder: A large data-driven functional magnetic resonance imaging study

OBJECTIVES

Cognitive impairment occurs in approximately 50% of remitted patients with bipolar disorder (BD). However, there exists no treatment with replicated and robust efficacy on cognition in BD. This is partially due to limited insight into the neuronal underpinnings of cognitive impairment in these patients. This is the first study to investigate neuronal underpinnings of cognitive impairment in a large functional magnetic resonance imaging (fMRI) dataset comparing neural activity patterns between distinct neurocognitive subgroups of partially or fully remitted patients with BD.

METHODS

Patients (n = 153) and healthy controls (HC) (n = 52) underwent neuropsychological assessment and fMRI, during which they performed a verbal N-back working memory (WM) task. Based on hierarchical cluster analysis of neuropsychological test performance, patients were grouped into one of two neurocognitive subgroups (cognitively impaired, n = 91; cognitively normal compared to HC, n = 62) that were compared on WM-related neural activity.

RESULTS

Cognitively impaired patients displayed WM-related hypo-activity in left dorsolateral prefrontal cortex and frontal and parietal regions within a cognitive control network (CCN) as well as hyper-activity in the default mode network (DMN) compared to cognitively normal patients. In contrast, cognitively normal patients only exhibited hypo-activity within a small cluster in the superior frontal gyrus relative to HC.

CONCLUSIONS

Cognitive impairment in BD seems to originate from a failure to recruit key regions in the CCN and to suppress task-irrelevant DMN activity during cognitive performance. These results highlight modulation of aberrant dorsal prefrontal and DMN activity as a putative target for pro-cognitive treatment in BD.