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.

Predicting recurrence of major depressive episodes using the Depression Implicit Association Test: A Canadian biomarker integration network in depression (CAN-BIND) report.

Identifying clinically relevant predictors of depressive recurrence following treatment for Major Depressive Disorder (MDD) is critical for relapse prevention. Implicit self-depressed associations (SDAs), defined as implicit cognitive associations between elements of depression (e.g., sad, miserable) and oneself, often persist following depressive episodes and may represent a cognitive biomarker for future recurrences. Thus, we examined whether SDAs, and changes in SDAs over time, prospectively predict depressive recurrence among treatment responders in the CAN-BIND Wellness Monitoring for MDD Study, a prospective cohort study conducted across 5 clinical centres. A total of 96 patients with MDD responding to various treatments were followed an average of 1.01 years. Participants completed the Depression Implicit Association Test (DIAT) - a computer-based measure of SDAs - every 8 weeks on a tablet device. Survival analyses indicated that greater SDAs at baseline and increases in SDAs over time predicted shorter time to MDD recurrence, even after accounting for depressive symptom severity. The findings show that SDAs are a robust prognostic indicator of risk for MDD recurrence, and that the DIAT may be a feasible and low-cost clinical screening tool. SDAs also represent a potential mechanism underlying the course of recurrent depression and are a promising target for relapse prevention interventions.

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.

Brain age and cognitive functioning in first-episode bipolar disorder.

BACKGROUND: There is significant heterogeneity in cognitive function in patients with bipolar I disorder (BDI); however, there is a dearth of research into biological mechanisms that might underlie cognitive heterogeneity, especially at disease onset. To this end, this study investigated the association between accelerated or delayed age-related brain structural changes and cognition in early-stage BDI. METHODS: First episode patients with BDI (n = 80) underwent cognitive assessment to yield demographically normed composite global and domain-specific scores in verbal memory, non-verbal memory, working memory, processing speed, attention, and executive functioning. Structural magnetic resonance imaging data were also collected from all participants and subjected to machine learning to compute the brain-predicted age difference (brainPAD), calculated by subtracting chronological age from age predicted by neuroimaging data (positive brainPAD values indicating age-related acceleration in brain structural changes and negative values indicating delay). Patients were divided into tertiles based on brainPAD values, and cognitive performance compared amongst tertiles with ANCOVA. RESULTS: Patients in the lowest (delayed) tertile of brainPAD values (brainPAD range -17.9 to -6.5 years) had significantly lower global cognitive scores (p = 0.025) compared to patients in the age-congruent tertile (brainPAD range -5.3 to 2.4 yrs), and significantly lower verbal memory scores (p = 0.001) compared to the age-congruent and accelerated (brainPAD range 2.8 to 16.1 yrs) tertiles. CONCLUSION: These results provide evidence linking cognitive dysfunction in the early stage of BDI to apparent delay in typical age-related brain changes. Further studies are required to assess how age-related brain changes and cognitive functioning evolve over time.

Association of total peripheral inflammation with lower frontal and temporal lobe volumes in early-stage bipolar disorder: A proof-of-concept study.

BACKGROUND: We previously reported that in early-stage bipolar disorder (BD), frontal and temporal lobe volume reductions were more pronounced in patients with elevated BMI and more rapidly progressive in patients with additional weight gain. Elevated BMI is a pro-inflammatory state, and inflammation may contribute to brain volume reductions in BD. However, few studies have investigated the relationship between inflammation and brain volumes. METHODS: We conducted a proof-of-concept analysis to investigate whether a composite measure of total peripheral inflammation derived from 9 cytokines predicted lower frontal and temporal lobe volumes, measured with 3 T MRI, in early-stage BD. RESULTS: In 25 early-stage patients, linear regression models showed that greater total inflammation predicted lower white matter (WM) volumes in the left frontal lobe (ß = -0.691, p = 0.001) and bilateral temporal lobes (left: ß = -0.617, p = 0.003; right: ß = -0.636, p = 0.001). Greater inflammation also predicted lower right frontal WM, although this did not survive correction for multiple comparisons (ß = -0.557, p = 0.020). It did not predict frontal or temporal GM. Total inflammation was a stronger predictor of lower WM volumes than were individual cytokines. LIMITATIONS: Although the magnitude of the association between total inflammation and lower WM volumes was large, our sample was small. Our findings require confirmation in further studies, with samples large enough to determine whether inflammation mediates the relationship between elevated BMI and brain volumes. CONCLUSIONS: This study supports the hypothesis that inflammation contributes to brain volume reductions in BD and suggests that total inflammatory burden best captures the impact of inflammation on the brain.

Criterion validity of the brief test of adult cognition by telephone (BTACT) for mild traumatic brain injury.

OBJECTIVES: There is a growing demand for remote assessment options for measuring cognition after mild traumatic brain injury (mTBI). The current study evaluated the criterion validity of the Brief Test of Adult Cognition by Telephone (BTACT) in distinguishing between adults with mTBI and trauma controls (TC) who sustained injuries not involving the head or neck. METHODS: The BTACT was administered to the mTBI (n = 46) and TC (n = 35) groups at 1-2 weeks post-injury. Participants also completed the Rivermead Post Concussion Symptoms Questionnaire. RESULTS: The BTACT global composite score did not significantly differ between the groups (t(79) = -1.04, p = 0.30); the effect size was small (d = 0.23). In receiver operating characteristic curve analyses, the BTACT demonstrated poor accuracy in differentiating between the groups (AUC = 0.567, SE = 0.065, 95% CI [0.44, 0.69]). The BTACT's ability to discriminate between mTBI and TCs did not improve after excluding mTBI participants (n = 15) who denied ongoing cognitive symptoms (AUC = 0.567, SE = 0.072, 95% CI [0.43, 0.71]). CONCLUSIONS: The BTACT may lack sensitivity to subacute cognitive impairment attributable to mTBI (i.e., not explained by bodily pain, post-traumatic stress, and other nonspecific effects of injury).

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.

Subjective cognitive functioning, depressive symptoms, and objective cognitive functioning in people with treatment-resistant psychosis.

Introduction: Relationships between subjective cognitive functioning (SCF), objective cognitive functioning (OCF), and depressive symptoms are poorly understood in treatment-resistant psychosis (TRP). This study (a) compares SCF in TRP using positively and negatively worded scales, (b) assess these scales' accuracy, and (c) explores the association between these scales and depressive symptoms. We hypothesised that both SCF scales would be highly correlated, minimally associated with OCF, and similarly associated with depressive symptoms. Methods: Archival clinical data from 52 TRP inpatients was utilised. OCF composite scores were derived from a broad neuropsychological battery. SCF was assessed using the norm-referenced PROMIS 2.0 Cognitive Abilities (positively worded) and Concerns (negatively worded) subscales. A depressive symptom score was derived from the Positive and Negative Syndrome Scale. Results: SCF ratings were higher in patients than OCF. There was a small but significant correlation between PROMIS subscales (r = .30). Neither PROMIS subscale was associated with OCF (r = -.11, r = .01). Depressive symptoms were correlated with the positively (r = -.29) but not negatively worded scale (r = -.13). Conclusion: Individuals with TRP inaccurately rate their cognitive functioning and tend to overestimate their ability. Positively and negatively worded SCF scales associate variably with depressive symptoms, indicating they may not be used interchangeably in TRP.

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.

Repetitive Transcranial Magnetic Stimulation Shows Longitudinal Improvements in Memory in Patients With Treatment-Resistant Depression.

BACKGROUND: Cognitive dysfunction (CD) is a commonly reported symptom of major depressive disorder (MDD). Patients with treatment-resistant depression (TRD) tend to experience greater rates of CD; however, treatment options are limited. Repetitive transcranial magnetic stimulation (rTMS) is effective in treating affective symptoms in patients with TRD, but its potential effect on CD in TRD has not been established. OBJECTIVES: This study sought to establish the potential cognitive benefits of rTMS in patients with TRD. MATERIALS AND METHODS: This study used data from a noninferiority clinical trial investigating two excitatory rTMS protocols to the left dorsolateral prefrontal cortex in unipolar outpatients with TRD. Cognitive testing was performed at baseline and three months posttreatment in 47 patients and a demographically matched cohort of 22 healthy volunteers. Changes in cognitive performance from baseline to posttreatment were assessed using repeated-measures analysis of variance, using both normative and individualized cognitive scoring methods. RESULTS: Patients with baseline neurocognitive dysfunction showed significant changes in verbal memory at three months posttreatment when using individualized cognitive scoring. Furthermore, improvement in verbal memory within this subset was associated with improvements in affective symptoms. LIMITATIONS: This analysis was performed on a relatively small sample of patients with TRD who were not prescreened for CD and did not include a clinical comparator group. CONCLUSIONS: rTMS may be associated with improvements in verbal memory in patients with TRD who present with global CD and who are clinical responders to the treatment. These findings warrant replication in a larger sample as well as further investigations into the neural mechanisms of cognitive improvement after rTMS.

Metacognitive knowledge and experience across multiple cognitive domains in euthymic bipolar disorder.

BACKGROUND: Metacognitive knowledge (MK; general awareness of cognitive functioning) and metacognitive experience (ME; awareness of cognitive performance on a specific cognitive task) represent two facets of metacognition that are critical for daily functioning, but are understudied in bipolar disorder. This study was conducted to evaluate MK and ME across multiple cognitive domains in individuals diagnosed with bipolar disorder and unaffected volunteers, and to investigate the association between metacognition and quality of life (QoL). METHODS: Fifty-seven euthymic participants with bipolar disorder and 55 demographically similar unaffected volunteers provided prediction and postdiction ratings of cognitive task performance across multiple cognitive domains. Self-ratings were compared to objective task performance, and indices of MK and ME accuracy were generated and compared between groups. Participants rated QoL on the Quality of Life in Bipolar Disorder Scale (QoL.BD). RESULTS: Metacognitive inaccuracies in both MK and ME were observed in participants with bipolar disorder, but only in select cognitive domains. Furthermore, most metacognitive inaccuracies involved underestimation of cognitive ability. Metacognitive indices were minimally associated with medication variables and mood symptoms, but several indices were related to QoL. CONCLUSIONS: Individuals with bipolar disorder demonstrate inaccuracies in rating their cognitive functioning and in rating their online cognitive task performance, but only on select cognitive functions. The tendency to underestimate performance may reflect a negative information processing bias characteristic of mood disorders. Metacognitive variables were also predictive of QoL, indicating that further understanding of cognitive self-appraisals in persons with bipolar disorder has significant clinical relevance.

Myelin water fraction decrease in individuals with chronic mild traumatic brain injury and persistent symptoms.

The diffuse and continually evolving secondary changes after mild traumatic brain injury (mTBI) make it challenging to assess alterations in brain-behaviour relationships. In this study we used myelin water imaging to evaluate changes in myelin water fraction (MWF) in individuals with chronic mTBI and persistent symptoms and measured their cognitive status using the NIH Toolbox Cognitive Battery. Fifteen adults with mTBI with persistent symptoms and twelve age, gender and education matched healthy controls took part in this study. We found a significant decrease in global white matter MWF in patients compared to the healthy controls. Significantly lower MWF was evident in most white matter region of interest (ROIs) examined including the corpus callosum (separated into genu, body and splenium), minor forceps, right anterior thalamic radiation, left inferior longitudinal fasciculus; and right and left superior longitudinal fasciculus and corticospinal tract. Although patients showed lower cognitive functioning, no significant correlations were found between MWF and cognitive measures. These results suggest that individuals with chronic mTBI who have persistent symptoms have reduced MWF.

Efficacy of Active vs Sham Intermittent Theta Burst Transcranial Magnetic Stimulation for Patients With Bipolar Depression: A Randomized Clinical Trial.

Importance: Major depressive episodes in bipolar disorder are common and debilitating. Repetitive transcranial magnetic stimulation is well established in the treatment of major depressive disorder, and the intermittent theta burst stimulation (iTBS) protocol is replacing conventional protocols because of noninferiority and reduced delivery time. However, iTBS has not been adequately studied in bipolar disorder and, therefore, its efficacy is uncertain. Objective: To determine whether iTBS to the left dorsolateral prefrontal cortex (LDLPFC) is safe and efficacious in the treatment of acute bipolar depression. Design, Setting, and Participants: This study was a double-blind, 4-week, randomized clinical trial of iTBS targeting the LDLPFC. Two Canadian academic centers recruited patients between 2016 and 2020. Adults with bipolar disorder type I or type II experiencing an acute major depressive episode were eligible if they had not benefited from a first-line treatment for acute bipolar depression recommended by the Canadian Network for Mood and Anxiety Treatments and were currently treated with a mood stabilizer, an atypical antipsychotic, or their combination. Seventy-one participants were assessed for eligibility, and 37 were randomized to daily sham iTBS or active iTBS using a random number sequence, stratified according to current pharmacotherapy. Data analysis was performed from April to September 2020. Interventions: Four weeks of daily active iTBS (120% resting motor threshold) or sham iTBS to the LDLPFC. Nonresponders were eligible for 4 weeks of open-label iTBS. Main Outcomes and Measures: The primary outcome was the change in score on the Montgomery-Asberg Depression Rating Scale from baseline to study end. Secondary outcomes included clinical response, remission, and treatment-emergent mania or hypomania. Results: The trial was terminated for futility after 37 participants (23 women [62%]; mean [SD] age, 43.86 [13.87] years; age range, 20-68 years) were randomized, 19 to sham iTBS and 18 to active iTBS. There were no significant differences in Montgomery-Asberg Depression Rating Scale score changes (least squares mean difference between groups, -1.36 [95% CI, -8.92 to 6.19; P = .91] in favor of sham iTBS), and rates of clinical response were low in both the double-blind phase (3 of 19 participants [15.8%] in the sham iTBS group and 3 of 18 participants [16.7%] in the active iTBS group) and open-label phase (5 of 21 participants [23.8%]). One active iTBS participant had a treatment emergent hypomania, and a second episode occurred during open-label treatment. Conclusions and Relevance: iTBS targeting the LDLPFC is not efficacious in the treatment of acute bipolar depression in patients receiving antimanic or mood stabilizing agents. Additional research is required to understand how transcranial magnetic stimulation treatment protocols differ in efficacy between unipolar and bipolar depression. Trial Registration: ClinicalTrials.gov Identifier: NCT02749006.

Weight gain as a risk factor for progressive neurochemical abnormalities in first episode mania patients: a longitudinal magnetic resonance spectroscopy study.

BACKGROUND: We previously reported that bipolar disorder (BD) patients with clinically significant weight gain (CSWG; ⩾7% of baseline weight) in the 12 months after their first manic episode experienced greater limbic brain volume loss than patients without CSWG. It is unknown whether CSWG is also a risk factor for progressive neurochemical abnormalities. METHODS: We investigated whether 12-month CSWG predicted greater 12-month decreases in hippocampal N-acetylaspartate (NAA) and greater increases in glutamate + glutamine (Glx) following a first manic episode. In BD patients (n = 58) and healthy comparator subjects (HS; n = 34), we measured baseline and 12-month hippocampal NAA and Glx using bilateral 3-Tesla single-voxel proton magnetic resonance spectroscopy. We used general linear models for repeated measures to investigate whether CSWG predicted neurochemical changes. RESULTS: Thirty-three percent of patients and 18% of HS experienced CSWG. After correcting for multiple comparisons, CSWG in patients predicted a greater decrease in left hippocampal NAA (effect size = -0.52, p = 0.005). CSWG also predicted a greater decrease in left hippocampal NAA in HS with a similar effect size (-0.53). A model including patients and HS found an effect of CSWG on Δleft NAA (p = 0.007), but no diagnosis effect and no diagnosis × CSWG interaction, confirming that CSWG had similar effects in patients and HS. CONCLUSION: CSWG is a risk factor for decreasing hippocampal NAA in BD patients and HS. These results suggest that the well-known finding of reduced NAA in BD may result from higher body mass index in patients rather than BD diagnosis.

Cognitive Outcomes with Sequential Escitalopram Monotherapy and Adjunctive Aripiprazole Treatment in Major Depressive Disorder: A Canadian Biomarker Integration Network in Depression (CAN-BIND-1) Report.

BACKGROUND: Cognitive deficits are detectable in major depressive disorder (MDD). The cognitive impact of antidepressants remains unclear, as does the cognitive effects of aripiprazole in MDD, a commonly used adjunct with putative pro-cognitive properties. OBJECTIVES: In this multi-centre, open-label study, cognitive changes associated with escitalopram monotherapy and adjunctive aripiprazole were examined. METHODS: Acutely depressed participants with MDD (n = 209) received 8 weeks of escitalopram. Non-responders received an additional 8 weeks of adjunctive aripiprazole (ESC-ARI, n = 88), while responders (ESC-CONT, n = 82) continued escitalopram monotherapy (n = 39 lost to attrition). ESC-ARI, ESC-CONT and matched healthy participants (n = 112) completed the Central Nervous System Vital Signs cognitive battery at baseline, 8 and 16 weeks. Linear mixed models compared participants with MDD cognitive trajectories with healthy participants. RESULTS: Participants with MDD displayed poorer baseline global cognition (assessed via the Neurocognitive Index), composite memory and psychomotor speed vs healthy participants. There were no statistically significant changes in participants with MDD receiving escitalopram monotherapy from baseline to week 8 in the neurocognitive index, reaction time, complex attention, cognitive flexibility, memory or psychomotor speed. Overall symptom severity changes were not associated with cognitive changes. The ESC-CONT group displayed no significant cognitive changes from weeks 8 to 16; reaction time worsened in the ESC-ARI group (p = 0.008) from weeks 8 to 16, independent of symptom change. CONCLUSIONS: Escitalopram monotherapy in acute MDD did not result in significant cognitive improvements. We provide novel evidence that escitalopram continuation in responders does not adversely affect cognition, but adjunctive aripiprazole in escitalopram non-responders worsens reaction time. Treatments targeting cognitive dysfunction are needed in MDD. CLINICALTRIALS. GOV IDENTIFIER: NCT01655706; 2 August, 2012.

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

Introduction: This narrative review of systematic reviews and meta-analyses aims at compiling available evidence in various aspects of neurocognitive functioning in Bipolar Disorder (BD). Methods: We conducted a MEDLINE literature search and identified 38 relevant systematic reviews and metaanalyses. Results: Current evidence suggests that BD is associated with cognitive impairment across multiple domains and during all clinical states. However, there is a considerable cognitive heterogeneity within BD, which cannot be explained by clinical subtypes, and the pattern of neurocognitive impairment in BD overlaps with other psychiatric conditions such as major depression and schizophrenia. Residual depressive symptoms, poor clinical course and higher number of manic episodes may negatively impact cognitive performance, which is a major predictor of general functioning in BD. Evidence from available prospective studies does not support the notion of progressive cognitive decline in BD while some evidence exists to suggest patients may show some improvements in cognitive functioning following the first manic episode. Furthermore, a subset of patients may show premorbid cognitive abnormalities that could signal an early neurodevelopmental aetiology. Preliminary findings from small studies identify potential pro-cognitive effects of Cognitive Remediation, erythropoietin, intranasal insulin, lurasidone, mifepristone, repetitive Transcranial Magnetic Stimulation and transcranial Direct Current Stimulation in BD. Discussion: Longitudinal studies in high-risk individuals can provide a better understanding of the development and progression of neurocognitive impairment in BD. Largescale randomised control trials are needed to compare the pro-cognitive efficacy of various pharmacological and non-pharmacological interventions in different cognitive subgroups of patients at different stages of BD.

Cognitive subgroups in first episode bipolar I disorder: Relation to clinical and brain volumetric variables.

OBJECTIVE: Distinct cognitive subgroups are seen in patients with long duration bipolar I disorder (BDI), possibly reflective of underlying pathophysiological differences. It is unknown whether such cognitive heterogeneity is present at illness onset. We applied latent class analysis (LCA) to cognitive test scores in first episode BDI patients. Exploratory analysis elucidated whether impaired subgroups were characterized by 'early neurodevelopmental' (low premorbid IQ and intracranial volume) versus 'later neurodevelopmental' (decline from premorbid to current IQ, changes in relative grey (GM)/white (WM) matter volumes) pathology. METHODS: Recently recovered first manic episode BDI patients (n = 91) and healthy controls (HC, n = 63) comprised the study sample. LCA identified subgroups based on processing speed, verbal memory, non-verbal memory, executive functioning, attention and working memory scores. Subgroups were compared amongst each other and HC on premorbid/current IQ, intracranial (ICV), total brain and regional volumes. RESULTS: Three cognitive subgroups emerged: (i) globally impaired (GI, n = 31), scoring 0.5-1 SD below demographically corrected norms across domains, (ii) selectively impaired (SI, n = 47), with predominant processing speed deficits and (iii) high performing (HP, n = 13), with above-average cognitive performance. GI patients showed a 'later neurodevelopmental' pattern, with normal ICV, significant decline from premorbid to current IQ, higher total GM and lower total WM (with respect to total brain volume) versus SI and HC (p = 0.003). GI patients had higher left frontal pole GM versus HC (p < 0.05, FWE corrected). CONCLUSIONS: A globally impaired patient subgroup is identifiable in first episode BDI, possibly characterized by unique neurodevelopmental pathologic processes proximal to illness onset.

Early intervention for people at high risk of developing bipolar disorder: a systematic review of clinical trials.

Early intervention approaches are built on the premise of preventing disability, burden, and cognitive sequelae caused by bipolar disorder. The objective of this systematic review was to characterise the effectiveness of all the available psychological and pharmacological treatments for early intervention in people at high risk of developing bipolar disorder. The study was registered with PROSPERO (CRD42019133420). We did a systematic search to identify studies published in ten databases up to March 27, 2020. Randomised controlled trials and cohort studies that assessed the effect of pharmacological or psychological interventions in people at high risk of developing bipolar disorder were included. Studies of first episodes of mania were excluded. Eligible papers were assessed for quality and data were extracted. The primary outcomes were change in manic and depressive symptoms from baseline to endpoint. Of the 2856 citations retrieved by our search, 16 studies were included; five evaluated pharmacotherapeutic strategies (three randomised controlled trials and two open-label studies), ten assessed psychotherapeutic strategies (four randomised controlled trials and six open-label studies), and one randomised controlled trial assessed combination therapy; these 16 trials included a total of 755 participants at high risk of developing bipolar disorder. Quality assessment indicated fair to good quality for open-label studies, and a high risk of bias in four randomised controlled trials. Among the pharmacotherapeutic interventions, there is preliminary support for the efficacy of aripiprazole in reducing mood symptoms in people at high risk of developing bipolar disorder. Psychological interventions were effective for various outcomes. There was substantial methodological heterogeneity across studies. This systematic review underscores the need for multicentre, prospective, methodologically homogeneous studies evaluating conversion to bipolar disorder as an outcome measure.

Assessment of Prorated Scoring of an Abbreviated Protocol for the National Institutes of Health Toolbox Cognition Battery.

OBJECTIVE: To evaluate an abbreviated NIH Toolbox Cognition Battery (NIHTB-CB) protocol that can be administered remotely without any in-person assessments, and explore the agreement between prorated scores from the abbreviated protocol and standard scores from the full protocol. METHODS: Participant-level age-corrected NIHTB-CB data were extracted from six studies in individuals with a history of stroke, mild traumatic brain injury (mTBI), treatment-resistant psychosis, and healthy controls, with testing administered under standard conditions. Prorated fluid and total cognition scores were estimated using regression equations that excluded the three fluid cognition NIHTB-CB instruments which cannot be administered remotely. Paired t tests and intraclass correlations (ICCs) were used to compare the standard and prorated scores. RESULTS: Data were available for 245 participants. For fluid cognition, overall prorated scores were higher than standard scores (mean difference = +4.5, SD = 14.3; p < 0.001; ICC = 0.86). For total cognition, overall prorated scores were higher than standard scores (mean difference = +2.7, SD = 8.3; p < 0.001; ICC = 0.88). These differences were significant in the stroke and mTBI groups, but not in the healthy control or psychosis groups. CONCLUSIONS: Prorated scores from an abbreviated NIHTB-CB protocol are not a valid replacement for the scores from the standard protocol. Alternative approaches to administering the full protocol, or corrections to scoring of the abbreviated protocol, require further study and validation.