Neuropsychological status of bipolar I disorder: impact of psychosis

A systematic review of research on neuropsychological measures in psychotic disorders from low and middle-income countries: The question of clinical utility

INTRODUCTION

Several studies of neuropsychological measures have been undertaken in patients with psychotic disorders from low- and middle-income countries (LMICs). It is, however, unclear if the measures used in these studies are appropriate for cognitive screening in clinical settings. We undertook a systematic review to determine if measures investigated in research on psychotic disorders in LMICs meet the clinical utility criteria proposed by The Working Group on Screening and Assessment.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses were employed. We determined if tests had been validated against a comprehensive test battery, the duration and scope of the tests, the personnel administering the tests, and the means of administration.

RESULTS

A total of 31 articles were included in the review, of which 11 were from Africa. The studies included 3254 participants with psychosis and 1331 controls. 3 studies reported on the validation of the test against a comprehensive cognitive battery. Assessments took 1 h or less to administer in 6/31 studies. The average number of cognitive domains assessed was four. Nonspecialized staff were used in only 3/31 studies, and most studies used pen and paper tests (17/31).

CONCLUSION

Neuropsychological measures used in research on psychotic disorders in LMICs typically do not meet the Working Group on Screening and Assessment clinical utility criteria for cognitive screening. Measures that have been validated in high-income countries but not in LMICs that do meet these criteria, such as the Brief Assessment of Cognition in Schizophrenia, therefore deserve further study in LMIC settings.

Distinguishing patterns of impairment on inhibitory control and general cognitive ability among bipolar with and without psychosis, schizophrenia, and schizoaffective disorder

BACKGROUND

Deficits in inhibitory control on a Stop Signal Task (SST) were previously observed to be of similar magnitude across schizophrenia, schizoaffective, and bipolar disorder with psychosis, despite variation in general cognitive ability. Understanding different patterns of performance on the SST may elucidate different pathways to the impaired inhibitory control each group displayed. Comparing nonpsychotic bipolar disorder to the psychosis groups on SST may also expand our understanding of the shared neurobiology of this illness spectrum.

METHODS

We tested schizophrenia (n = 220), schizoaffective (n = 216), bipolar disorder with (n = 192) and without psychosis (n = 67), and 280 healthy comparison participants with a SST and the Brief Assessment of Cognition in Schizophrenia (BACS), a measure of general cognitive ability.

RESULTS

All patient groups had a similar degree of impaired inhibitory control over prepotent responses. However, bipolar groups differed from schizophrenia and schizoaffective groups in showing speeded responses and inhibition errors that were not accounted for by general cognitive ability. Schizophrenia and schizoaffective groups had a broader set of deficits on inhibition and greater general cognitive deficit, which fully accounted for the inhibition deficits. No differences were found between the clinically well-matched bipolar with and without psychosis groups, including for inhibitory control or general cognitive ability.

CONCLUSIONS

We conclude that 1) while impaired inhibitory control on a SST is of similar magnitude across the schizo-bipolar spectrum, including nonpsychotic bipolar, different mechanisms may underlie the impairments, and 2) history of psychosis in bipolar disorder does not differentially impact inhibitory behavioral control or general cognitive abilities.

Neurocognitive impairment and evidence-based treatment options in Bipolar disorder

BACKGROUND

The current paper briefly summarizes the literature on the neurocognitive deficit and its treatment in BD patients.

METHODS

The material was chosen on the basis of previous systematic reviews the author has taken part in.

RESULTS

The data so far suggest that the deficit is qualitatively similar but quantitatively milder in comparison to schizophrenia, it is present already since the first episode, is weakly related to mood symptoms and somewhat stronger to psychotic symptoms, it probably determines much of the disability and treatment is problematic. This deficit is also present during periods of euthymia. The possible adverse effect of psychotropic medication is rather small if any at all and is confounded by the specific clinical symptoms, for which medication is used for their treatment. This is especially true concerning antipsychotics and psychotic symptoms. The origin and the etiopathogenesis of the core neurocognitive impairment remain elusive. The presence of a neurodegenerative and of a neurodevelopmental component has both data in favor and against and they are both the focus of debate.

CONCLUSIONS

Treatment of the neurocognitive deficit and restoration of functioning is problematic. The data are limited and treatment options are few and with a weak overall effect. Pharmacological treatments, ECT and rTMS present some hard data, while the literature is inconclusive concerning psychotherapeutic interventions.

The characteristics of psychotic features in bipolar disorder

BACKGROUND

In a large and comprehensively assessed sample of patients with bipolar disorder type I (BDI), we investigated the prevalence of psychotic features and their relationship with life course, demographic, clinical, and cognitive characteristics. We hypothesized that groups of psychotic symptoms (Schneiderian, mood incongruent, thought disorder, delusions, and hallucinations) have distinct relations to risk factors.

METHODS

In a cross-sectional study of 1342 BDI patients, comprehensive demographical and clinical characteristics were assessed using the Structured Clinical Interview for DSM-IV (SCID-I) interview. In addition, levels of childhood maltreatment and intelligence quotient (IQ) were assessed. The relationships between these characteristics and psychotic symptoms were analyzed using multiple general linear models.

RESULTS

A lifetime history of psychotic symptoms was present in 73.8% of BDI patients and included delusions in 68.9% of patients and hallucinations in 42.6%. Patients with psychotic symptoms showed a significant younger age of disease onset (β = -0.09, t = -3.38, p = 0.001) and a higher number of hospitalizations for manic episodes (F11 338 = 56.53, p < 0.001). Total IQ was comparable between groups. Patients with hallucinations had significant higher levels of childhood maltreatment (β = 0.09, t = 3.04, p = 0.002).

CONCLUSIONS

In this large cohort of BDI patients, the vast majority of patients had experienced psychotic symptoms. Psychotic symptoms in BDI were associated with an earlier disease onset and more frequent hospitalizations particularly for manic episodes. The study emphasizes the strength of the relation between childhood maltreatment and hallucinations but did not identify distinct subgroups based on psychotic features and instead reported of a large heterogeneity of psychotic symptoms in BD.

Neuropsychological profiles of adult bipolar disorder patients with and without comorbid attention-deficit hyperactivity disorder

Background

Comorbid attention-deficit/hyperactivity disorder (ADHD) is common in bipolar disorder and associated with worse outcomes. Cognitive testing might be a tool to identify this group. Here we compare the neuropsychological profiles of bipolar disorder patients with (BD + cADHD) and without (BD − cADHD) childhood attention-deficit hyperactivity disorder.

Methods

Adult patients with BD  −  cADHD (n = 66), BD + cADHD (n = 32), and healthy controls (n = 112) were tested using a comprehensive battery of neuropsychological tests. Patients underwent rigorous diagnostic assessments for bipolar disorder and ADHD, as well as a parental interview to establish childhood ADHD.

Results

The neuropsychological profiles of the groups were similar, except that the BD + cADHD group performed significantly worse on working memory. Working memory did not differ between those in the BD + cADHD group who only had a history of childhood ADHD and those that still met criteria for ADHD in adulthood.

Conclusions

Cognitive testing had limited power to differentiate between bipolar disorder adults with and without childhood ADHD. The BD + cADHD subgroup cannot explain the significant cognitive heterogeneity seen in bipolar disorder patients.

Electronic supplementary material

The online version of this article (10.1186/s40345-019-0149-9) contains supplementary material, which is available to authorized users.

Effect of psychotic symptoms on cognitive impairment in patients with bipolar disorder

BACKGROUND

A considerable proportion of patients with bipolar disorder (BD) have psychotic symptoms during the illness. This subset of BD due to its genetic susceptibility and family segregation has considerable overlap with schizophrenia. However, the extent to which BD patients with psychotic symptoms and without psychotic symptoms differ on neurocognitive functions is still not completely clear.

AIM

The aim of this study was to examine the neurocognitive functions in BD patients with psychotic symptoms and BD without psychotic symptoms in comparison with healthy volunteers (HVs).

MATERIALS AND METHODS

Thirty patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition BD (16 with psychotic symptoms) and thirty age- and sex-matched HVs were recruited in the study. Clinical severity was assessed using structured rating scales. The presence of psychotic symptoms was assessed using the Lifetime Dimensions of Psychosis Scale (LDPS). All patients underwent tests, namely continuous performance test, Stroop Word-Color interference test, and Wisconsin Card Sorting Test, to measure executive functions. Differences between groups were examined using analysis of covariance with age and sex as covariates.

RESULTS

There was a significant difference between groups on the performance of all the three tests, with patients performing poorer than HVs. While the HVs differed from both BD with psychotic symptoms and without psychotic symptoms, there was no difference between BD patients with and without psychotic symptoms. There was no significant correlation between LDPS score and scores on neurocognitive tests.

CONCLUSION

The study findings, at least with respect to cognitive function, suggest that BD with psychotic symptoms may not be a categorically distinct subtype of BD. Cognitive functions need to be assessed in all patients with BD, regardless of psychotic symptoms, and remediation interventions need to be provided.

Neurocognition and functional outcome in patients with psychotic, non-psychotic bipolar I disorder, and schizophrenia. A five-year follow-up

Background:

Bipolar disorder (BD) and schizophrenia (SZ) are characterized by neurocognitive and functional deficits with marked heterogeneity. It has been suggested that BD with a history of psychotic symptoms (BD-P) could constitute a phenotypically homogeneous subtype characterized by greater neurocognitive and functional impairments, or by a distinct trajectory of such deficits. The aim of this study was to compare the neurocognitive and functional course of euthymic BD-P, euthymic BD patients without a history of psychosis (BD-NP), stabilized patients with schizophrenia and healthy subjects, during a five-year follow-up.

Methods:

Neurocognitive and psychosocial function was examined in 100 euthymic patients with BD (50 BD-P, 50 BD-NP), 50 stabilized patients with schizophrenia (SZ), and 51 healthy controls (HC) at baseline (T1), and after a 5-year follow-up (T2).

Results:

The course of both neurocognitive performance and functional outcome of patients with SZ and BD (BD-P and BD-NP) is stable. The profile of neurocognitive impairment of patients with SZ or BD (BD-P and BD-NP), is similar, with only quantitative differences circumscribed to certain domains, such as working memory. The subgroup of patients with BD-NP does not show functional deterioration.

Conclusions:

We have not found evidence of progression in the neurocognitive or psychosocial impairment in any of the three groups of patients, although it cannot be dismissed the possibility of a subset of patients with a progressive course. Other longitudinal studies with larger samples and longer duration are necessary to confirm these findings.

Cognitive Deficits in Psychotic Disorders: A Lifespan Perspective

Individuals with disorders that include psychotic symptoms (i.e. psychotic disorders) experience broad cognitive impairments in the chronic state, indicating a dimension of abnormality associated with the experience of psychosis. These impairments negatively impact functional outcome, contributing to the disabling nature of schizophrenia, bipolar disorder, and psychotic depression. The robust and reliable nature of cognitive deficits has led researchers to explore the timing and profile of impairments, as this may elucidate different neurodevelopmental patterns in individuals who experience psychosis. Here, we review the literature on cognitive deficits across the life span of individuals with psychotic disorder and psychotic-like experiences, highlighting the dimensional nature of both psychosis and cognitive ability. We identify premorbid generalized cognitive impairment in schizophrenia that worsens throughout development, and stabilizes by the first-episode of psychosis, suggesting a neurodevelopmental course. Research in affective psychosis is less clear, with mixed evidence regarding premorbid deficits, but a fairly reliable generalized deficit at first-episode, which appears to worsen into the chronic state. In general, cognitive impairments are most severe in schizophrenia, intermediate in bipolar disorder, and the least severe in psychotic depression. In all groups, cognitive deficits are associated with poorer functional outcome. Finally, while the generalized deficit is the clearest and most reliable signal, data suggests specific deficits in verbal memory across all groups, specific processing speed impairments in schizophrenia and executive functioning impairments in bipolar disorder. Cognitive deficits are a core feature of psychotic disorders that provide a window into understanding developmental course and risk for psychosis.

Sex-related variation of neurocognitive functioning in bipolar disorder: Focus on visual memory and associative learning

Bipolar disorder (BD) is associated with cognitive deficits in attention, verbal memory and executive functions. However, only few studies have examined sex effects on cognition despite their clinical relevance. Given that visual memory/ learning has been understudied the aim of our study was to investigate sex-related variation in cognition (executive functions and visual memory/ learning) in BD. Cognitive performance of 60 bipolar-I patients and 30 healthy controls was evaluated by using CANTAB battery tasks targeting spatial memory (SRM), paired associative learning (PAL) and executive functions. We fitted a multivariate analysis of covariance (MANCOVA), followed by task-specific ANCOVAs. A significant diagnosis by sex interaction effect was detected (MANCOVA); specifically, diagnosis-specific sex effects were found for SRM and PAL, as healthy males outperformed healthy females but this pattern was attenuated in BD patients. Patients' clinicodemographic characteristics, current psychopathology or medication status did not differ across sexes and were, therefore, unlikely to explain detected sex effects. Our study is one of few studies to assess sex-related variation in cognition in BD and the first to record a diagnosis-specific sex effect for two tasks of visuo-spatial memory/ learning, indicating that sex-related variation in healthy subjects is disrupted in BD.

Differentiating between clinical and behavioral phenotypes in first-episode psychosis during maintenance of visuospatial working memory

INTRODUCTION

We probed the neural basis of working memory in individuals with first episode of psychosis (FEP) and assessed how these neural abnormalities are associated with behavioral performance and/or core to psychosis pathophysiology.

METHODS

FEP (N=35) and matched controls (N=25) performed a visuospatial working memory task during fMRI acquisition. We isolated neural activity during the maintenance period and examined neural activity within regions typically engaged during a working memory task. Functional connectivity estimates were derived using psychophysiological interaction analysis. We examined correlations between brain function and behavioral performance and clinical symptomatology.

RESULTS

FEP had reduced accuracy and slower reaction times compared to controls (p<0.05, q<0.05). During the maintenance period, FEP exhibited reduced right dorsolateral prefrontal cortex (DLPFC) activation compared to controls (p=0.007, q=0.01), even when behavioral performance was matched between groups (p=0.01, q=0.03). Unlike controls, FEP failed to show increased dorsal anterior cingulate (dACC) activity with increased load level (p=0.02, q=0.06). Compared to controls, FEP showed increased negative DLPFC-dACC coupling during the maintenance period (p=0.05). Increased DLPFC activation was significantly associated with greater negative symptoms (p<0.005, q=0.02), while greater dACC activation was significantly associated with better performance in FEP (p<0.05, q<0.17).

CONCLUSION

WM impairment in psychosis may be specific to abnormalities in the ability of frontal systems processing executive commands (DLPFC) and monitoring performance (dACC) during the maintenance of information. Our results add to accumulating evidence indicating that DLPFC abnormalities may be core to psychosis psychopathology. We also provide new insights regarding how DLPFC abnormalities may undermine dACC processing during the maintenance of information.

Neurocognitive features in clinical subgroups of bipolar disorder: A meta-analysis

OBJECTIVE

There is a significant cognitive heterogeneity in bipolar disorder (BD). The aim of this systematic review was to examine the potential distinctive neuropsychological of features of clinical subgroups of BD. A literature search investigating cognitive differences between potential subtypes of BD was conducted.

METHODS

It was possible to conduct a meta-analysis of studies investigating the relationship between cognitive deficits and subgroups of DSM-IV BD (type I (BD-I) and type II (BD-II)), subgroups based on history of psychosis (PBD and NPBD). The cognitive domains investigated in this meta-analysis included verbal memory, visual memory, processing speed, executive functions speed (EF-speed), EF-accuracy, attention, working memory, social cognition. Current meta-analysis included 48 reports and compared cognitive performances of 1211 BD-I and 836 BD-II patients. It also compared cognitive functioning in 1017 PBD and 744 NPBD patients.

RESULTS

Both history of psychosis (d = 0.19) and BD-I (d = 0.17) diagnosis were associated with modestly more pronounced global cognitive impairment. In specific domains, BD-I significantly underperformed BD-II in verbal memory, processing speed, EF-speed, EF-accuracy (d = 0.15-0.26). PBD was associated with significantly impaired cognition compared to NPBD in verbal memory, processing speed, EF-speed, EF-accuracy, working memory and social cognition (d = 0.12-0.28).

CONCLUSION

In BD, history of psychosis and full-manic episode are modestly associated with increased cognitive deficits. Neurocognitive differences between clinical subtypes of BD are quite subtle and are not distinctive. Furthermore, other factors reflecting differences in illness severity can explain observed between-group differences. Most of the cognitive heterogeneity in BD cannot be explained by proposed subtypes of BD.

Neurocognitive functioning in first-episode Bipolar Disorder: Relationship with functional status

BACKGROUND

The aim of this study was to assess if an association between neurocognitive deficits and psychosocial functioning exists in first-episode BD patients.

METHODS

Twenty-five euthymic first-episode BD patients and thirty-seven healthy controls were recruited. History of suicide attempts, psychiatric comorbidities, pharmacological exposure, and previous depressive episodes were investigated. Performances on neurocognitive domains (verbal memory, attention, processing speed, and executive functions) as well as a measure of psychosocial functioning were used as outcomes.

RESULTS

First-episode BD patients showed medium-to-large size deficits on measures of attention, processing speed, and executive functions. A significant association between verbal memory and psychosocial functioning at the moment of BD diagnosis was detected (beta coefficient -3.9, IC 95% -6.7 to -1.2, p < 0.01).

CONCLUSIONS

A relationship between cognitive performance at the moment of BD diagnosis and psychosocial functioning was detected. Possible therapeutic implications of this finding are discussed.

Cognitive function, treatment response to lithium, and social functioning in Japanese patients with bipolar disorder

OBJECTIVES

Patients with bipolar disorder often suffer from cognitive impairment that significantly influences their functional outcome. However, it remains unknown whether lithium has a central role in cognition and functional outcome. We examined whether cognition and functional outcome were predicted by demographic and clinical variables, including the response to lithium, in lithium-treated patients with bipolar disorder.

METHODS

We evaluated 96 lithium-treated euthymic patients with bipolar disorder and 196 age- and-gender-matched healthy controls, using the Brief Assessment of Cognition in Schizophrenia (BACS). The patients were also assessed using the Social Functioning Scale (SFS) and "The Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder" (Alda) scale, which was evaluated as either a continuous measure of the total scale or a dichotomous criterion.

RESULTS

Multiple regression analysis revealed two key findings: first, that the premorbid intelligence quotient, age, and number of mood episodes were predictors of the BACS composite score; and, second, that the BACS composite score, negative symptoms, and continuous measure on the total Alda scale (but not its dichotomy) predicted the total SFS score. Structural equation modeling (SEM) was used to confirm these findings, and additionally revealed that the Alda scale was significantly associated with negative symptoms and also the number of mood episodes, regardless of how it was evaluated.

CONCLUSIONS

SEM delineated how demographic and clinical variables, cognitive performance, and response to lithium treatment were causally associated with, and converged on, social function. The putative role of the Alda scale for social function warrants further study.

Neurocognition in patients with psychotic and non-psychotic bipolar I disorder. A comparative study with individuals with schizophrenia

BACKGROUND

It has been suggested that patients with bipolar disorder with psychotic symptoms (BD-P) have larger neurocognitive impairment than patients with bipolar disorder without a history of psychotic symptoms (BD-NP). The objective of this study was to compare neurocognitive performance of BD-P and BD-NP relative to a group of patients with schizophrenia (SZ), and healthy controls (HC).

METHODS

Neurocognitive function was examined in 100 subjects with bipolar I disorder (50 BD-P, 50 BD-NP), 50 SZ, and 51 HC. All patients with BD fulfilled criteria for euthymia, while all SZ patients were stabilised for at least the previous 3 months.

RESULTS

Patients with BD-P and BD-NP performed worse than HC in all neurocognitive measures, except for sustained attention. Differences between BD-P and BD-NP were subtle and circumscribed to the working memory domain (effect size: 0.29). SZ performed worse than BD-NP in the neurocognitive composite index (NCI) and in the working memory domain. There were no differences between SZ and BD-P in any neurocognitive measure.

LIMITATIONS

The relatively small sample size, the cross-sectional design and, that patients were receiving pharmacological treatment are the main limitations of this study.

CONCLUSIONS

Our findings show that the three groups of patients have a large neurocognitive impairment. Differences are quantitative and only present in some neurocognitive domains, such as working memory. These results suggest that patients with BD and SZ can benefit from the same strategies of cognitive remediation.

Clinical and treatment-related predictors of cognition in bipolar disorder: focus on visual paired associative learning

Bipolar disorder (BD) is associated with impairment in cognitive domains such as verbal memory and executive functions. However, visual paired associative learning (PAL) has been far less researched. Neurocognitive dysfunction in BD patients has been related to several clinical factors, but data on the effect of medication are relatively scarce and inconsistent. The aim of our study was to explore the effect of clinical and treatment-related parameters on executive functions and visual memory/learning, including PAL, in BD. Cognitive performance of 60 bipolar I patients and 30 healthy subjects was evaluated by using CANTAB battery tasks targeting spatial recognition memory, PAL and executive functions (set shifting, planning, inhibitory control). Bipolar patients showed poorer performance in PAL, set shifting, planning and inhibitory control than healthy subjects; however, only differences in PAL and planning survived correction for multiple comparisons. Number of previous manic episodes and illness duration predicted worse performance in set shifting and PAL, respectively, whereas current treatment with valproate predicted better performance in PAL. This is one of the first studies to assess clinical and treatment-related predictors of PAL in BD. We report a possibly beneficial effect of valproate on PAL, which warrants further investigation.

Classification of cognitive performance in bipolar disorder

OBJECTIVE

To understand the etiology of cognitive impairment associated with bipolar disorder, we need to clarify potential heterogeneity in cognitive functioning. To this end, we used multivariate techniques to study if the correlation structure of cognitive abilities differs between persons with bipolar disorder and controls.

METHOD

Clinically stable patients with bipolar disorder (type I: n = 64; type II: n = 44) and healthy controls (n = 86) were assessed with a wide range of cognitive tests measuring executive function, speed, memory, and verbal skills. Data were analysed with multivariate techniques.

RESULTS

A distinct subgroup (∼30%) could be identified that performed significantly poorer on tests concerning memory function. This cognitive phenotype subgroup did not differ from the majority of bipolar disorder patients with respect to other demographic or clinical characteristics.

CONCLUSIONS

Whereas the majority of patients performed similar to controls, a subgroup of patients with bipolar disorder differed substantially from healthy controls in the correlation pattern of low-level cognitive abilities. This suggests that cognitive impairment is not a general trait in bipolar disorder but characteristic of a cognitive subgroup. This has important clinical implications for cognitive rehabilitation and remediation.

Impact of psychotic symptoms on cognitive functioning in child and adolescent psychiatric inpatients with severe mood disorders

Despite established differences in cognitive functioning of adults with mood disorder-related psychosis and those with non-affective psychotic disorders, there is limited evidence of the impact of psychotic symptoms on the cognitive functioning of children and adolescents with mood disorders. This study investigates IQ, working memory, and processing speed scores in 80 child and adolescent inpatients discharged from an intermediate care state psychiatric hospital, using a retrospective chart review. Associations between diagnosis based on DSM-IV criteria (7 with Major Depression- MDD; 43 with Bipolar Disorders-BD, and 30 with Mood Disorders Not Otherwise Specified-NOS), presence of current psychotic features, and cognitive functioning (WISC-IV IQ, Coding, Symbol Search, and Digit Span) were investigated using Multivariate Analyses of Variance. No differences were found in cognitive functioning between patients with MDD and BD, or between those with severe Mood Disorders (MDD or BD) and those with NOS, when controlling for age, gender, and presence of psychotic features. However, patients with severe mood disorders and psychotic features showed lower IQs and greater working memory deficits than those without psychotic features or NOS. Results are discussed in terms of treatment planning for children and adolescents at risk for developing psychotic symptoms and severe mood disorders.

Biological aspects and candidate biomarkers for psychotic bipolar disorder: A systematic review

AIM

We carried out a systematic review of the available literature about potential biomarkers of psychotic bipolar disorder (BD-P), a specific subset presenting worse outcome and greater risk of relapse than non-psychotic bipolar disorder (BD-NP).

METHODS

We searched the main psychiatric databases (PubMed, ISI Web of Knowledge, PsychInfo). Only original articles with the main topic of BD-P compared to schizophrenia/BD-NP/healthy controls (HC) written in English from 1994 to 2015 were included.

RESULTS

BD-P patients presented higher kynurenic acid levels in the cerebrospinal fluid, elevated anti- S accharomyces cerevisiae antibodies levels, and lower serum levels of dehydroepiandrosterone sulfate and progesterone than BD-NP/HC. Event-related potentials abnormalities have been identified in BD-P with respect to BD-NP. BD-P patients also presented bigger ventricles but similar hippocampal volumes compared to BD-NP/HC. Although the results are contrasting, some cognitive deficits seemed to be related to the psychotic dimension of bipolar affective disorder, such as impairment in verbal/logical memory, working memory, verbal and semantic fluency and executive functioning. Finally, polymorphisms of genes, such as NRG1, 5HTTLPR (s), COMT, DAOA and some chromosome regions (16p12 and 13q), were positively associated with BD-P.

CONCLUSION

Data about the identification of specific biomarkers for BD-P are promising, but most of them have not yet been replicated. They could lead the clinicians to an early diagnosis and proper treatment, thus ameliorating outcome of BD-P and reducing the biological changes associated with a long duration of illness. Further studies with bigger samples are needed to detect more specific biological markers of the psychotic dimension of bipolar affective disorder.

A pilot study of a combined group and individual functional remediation program for patients with bipolar I disorder

BACKGROUND

Bipolar disorder has been associated with a decrease in cognitive functioning affecting the functional outcome of patients independent of mood states. However, there have only been few attempts to investigate the effects of functional remediation for patients with bipolar disorder. The current study investigates the feasibility and effectiveness of a combined group and individual functional remediation program for bipolar disorder, including both patients and their caregivers.

METHODS

Twelve participants diagnosed with bipolar I disorder, and their caregivers, were treated with a combined group and individual functional remediation program. The feasibility of the program was evaluated by dropout rates and participants' evaluations of the program. The effectiveness of the program was explored through the assessment of functional outcome at baseline, immediately post-treatment, and follow-up three months later.

RESULTS

The results indicate a high degree of satisfaction and a low dropout rate with the current program. Assessment of outcomes suggests improved functioning in the areas of autonomy and occupational functioning, evolving from baseline to follow-up.

LIMITATIONS

Due to a small sample size and the lack of a control group the results are preliminary.

CONCLUSIONS

This relatively brief intervention offers a more tailor-made approach to functional remediation and shows good feasibility, acceptability and improvement of functioning in patients with bipolar I disorder.

Childhood maltreatment and unfavourable clinical outcomes in bipolar disorder: a systematic review and meta-analysis

BACKGROUND

Bipolar disorder affects up to one in 25 individuals and identification of early risk indicators of negative outcomes could facilitate early detection of patients with greatest clinical needs and risk. We aimed to investigate the association between childhood maltreatment and key negative outcomes in patients with bipolar disorder.

METHODS

For this systematic review and meta-analysis we searched MEDLINE, PsycINFO, and Embase to identify articles published before Jan 1, 2015, examining the association of maltreatment (physical, sexual, or emotional abuse, neglect, or family conflict) before age 18 years with clinical features and course of illness in bipolar disorder. Data were extracted from published reports and any missing information was requested from investigators. We did 12 independent random-effects meta-analyses to quantify the associations between childhood maltreatment and course of illness or clinical features.

FINDINGS

We initially identified 527 records and after unsuitable studies were removed, our search yielded 148 publications of which 30 were used in the meta-analysis. Patients with bipolar disorder and history of childhood maltreatment had greater mania severity (six studies, 780 participants; odds ratio [OR] 2·02, 95% CI 1·21-3·39, p=0·008), greater depression severity (eight studies, 1007 participants; 1·57, 1·25-1·99, p=0·0001), greater psychosis severity (seven studies, 1494 participants; 1·49, 1·10-2·04, p=0·011), higher risk of comorbidity with post-traumatic stress disorder (eight studies, 2494 participants; 3·60, 2·45-5·30, p<0·0001), anxiety disorders (seven studies, 5091 participants; 1·90, 1·39-2·61, p<0·0001), substance misuse disorders (11 studies, 5469 participants; 1·84, 1·41-2·39, p<0·0001), alcohol misuse disorder (eight studies, 5040 participants; 1·44, 1·13-1·83, p=0·003), earlier age of bipolar disorder onset (14 studies, 5733 participants; 1·85, 1·43-2·40, p<0·0001), higher risk of rapid cycling (eight studies, 3010 participants; 1·89, 1·45-2·48, p<0·0001), greater number of manic episodes (seven studies, 3909 participants; 1·26, 1·09-1·47, p=0·003), greater number of depressive episodes (eight studies, 4025 participants; 1·38, 1·07-1·79, p=0·013), and higher risk of suicide attempt (13 studies, 3422 participants; 2·25, 1·88-2·70, p<0·0001) compared with those with bipolar disorder without childhood maltreatment. Overall, these associations were not explained by publication bias, undue effects of individual studies, or variation in study quality.

INTERPRETATION

Childhood maltreatment predicts unfavourable clinical features and course of illness in patients with bipolar disorder.

FUNDING

None.

Cognitive impairment in first-episode mania: a systematic review of the evidence in the acute and remission phases of the illness

There is evidence of cognitive impairment that persists in the remission phase of bipolar disorder; however, the extent of the deficits that occur from the first onset of the disorder remains unclear. This is the first systematic review on cognitive functioning in the early stages of bipolar I disorder. The aim of the study was to identify the patterns and degree of cognitive impairment that exists from first-episode mania. Three electronic databases (MEDLINE, PsycINFO and PubMed) were systematically searched for studies published from January 1980 to June 2014. Eligible studies were separated into two groups: acute and remission. The Newcastle-Ottawa quality assessment scale was utilised to measure the quality of the included studies. A total of seven studies (three acute and four remission), including 230 first-episode mania and 345 healthy control participants, were eligible for the review. The studies in the acute phase only examined aspects of executive functioning, with impairments identified in cognitive flexibility, though not in response inhibition and verbal fluency relative to healthy controls. The most consistent finding during the remission phase was a deficit in working memory, whereas in the other domains, the findings were equivocal. Non-verbal memory and verbal fluency were not impacted in remission from first-episode mania. In conclusion, deficits are present in some but not all areas of cognitive functioning during the early stages of bipolar I disorder. Further research is warranted to understand the longitudinal trajectory of change from first-episode mania.

Developmental trajectory of cognitive impairment in bipolar disorder: comparison with schizophrenia

Both schizophrenia and bipolar disorder (BP) are associated with neurocognitive deficits. However, it has been suggested that schizophrenia, but not BP, is characterised by premorbid cognitive impairments and neurodevelopmental abnormalities. In this paper, studies investigating neurocognitive deficits in premorbid, high-risk and first-episode BP were reviewed and these findings were compared with outcome of studies in schizophrenia. Available evidence suggests that cognitive deficits are evident in first-episode BP and such deficits can be evident even years before the onset of the illness in some patients. Trajectory of cognitive deficits from childhood to adulthood can be very similar in schizophrenia and many patients with BP. Developmental lag in acquisition of cognitive skills is a risk factor for both disorders. However, unlike schizophrenia, not only impaired cognition but also supranormal premorbid cognitive/scholastic performance predict BP. Neurodevelopmental cognitive impairment is evident in some but not all patients with BP. A model suggesting that only BP patients who share common genetic risk factors with schizophrenia have premorbid neurodevelopmental cognitive deficits is proposed. In this model, combination of absence of neurodevelopmental abnormalities and BP-related temperamental characteristics explains the relationship between supranormal cognition and risk for BP.

The neurocognitive functioning in bipolar disorder: a systematic review of data

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.

Impairments of working memory in schizophrenia and bipolar disorder: the effect of history of psychotic symptoms and different aspects of cognitive task demands

Comparisons of cognitive impairments between schizophrenia (SZ) and bipolar disorder (BPD) have produced mixed results. We applied different working memory (WM) measures (Digit Span Forward and Backward, Short-delay and Long-delay CPT-AX, N-back) to patients with SZ (n = 23), psychotic BPD (n = 19) and non-psychotic BPD (n = 24), as well as to healthy controls (HC) (n = 18) in order to compare the level of WM impairments across the groups. With respect to the less demanding WM measures (Digit Span Forward and Backward, Short-delay CPT-AX), there were no between group differences in cognitive performance; however, with respect to the more demanding WM measures (Long-delay CPT-AX, N-back), we observed that the groups with psychosis (SZ, psychotic BPD) did not differ from one another, but performed poorer than the group without a history of psychosis (non-psychotic BPD). A history of psychotic symptoms may influence cognitive performance with respect to WM delay and load effects as measured by Long-delay CPT-AX and N-back tests, respectively. We observed a positive correlation of WM performance with antipsychotic treatment and a negative correlation with depressive symptoms in BPD and with negative symptoms in SZ subgroup. Our study suggests that WM dysfunctions are more closely related to a history of psychosis than to the diagnostic categories of SZ and BPD described by psychiatric classification systems.

Regulating the High: Cognitive and Neural Processes Underlying Positive Emotion Regulation in Bipolar I Disorder

Although it is well established that Bipolar Disorder (BD) is characterized by excessive positive emotionality, the cognitive and neural processes that underlie such responses are unclear. We addressed this issue by examining the role that an emotion regulatory process called self-distancing plays in two potentially different BD phenotypes-BD with vs. without a history of psychosis-and healthy individuals. Participants reflected on a positive autobiographical memory and then rated their level of spontaneous self-distancing. Neurophysiological activity was continuously monitored using electroencephalogram. As predicted, participants with BD who have a history of psychosis spontaneously self-distanced less and displayed greater neurophysiological signs of positive emotional reactivity compared to the other two groups. These findings shed light on the cognitive and neural mechanisms underlying excessive positive emotionality in BD. They also suggest that individuals with BD who have a history of psychosis may represent a distinct clinical phenotype characterized by dysfunctional emotion regulation.

Neuropathological and neuromorphometric abnormalities in bipolar disorder: view from the medial prefrontal cortical network

The question of whether BD is primarily a developmental disorder or a progressive, neurodegenerative disorder remains unresolved. Here, we review the morphometric postmortem and neuroimaging literature relevant to the neuropathology of bipolar disorder (BD). We focus on the medial prefrontal cortex (mPFC) network, a key system in the regulation of emotional, behavioral, endocrine, and innate immunological responses to stress. We draw four main conclusions: the mPFC is characterized by (1) a decrease in volume, (2) reductions in neuronal size, and/or changes in neuronal density, (3) reductions in glial cell density, and (4) changes in gene expression. These data suggest the presence of dendritic atrophy of neurons and the loss of oligodendroglial cells in BD, although some data additionally suggest a reduction in the cell counts of specific subpopulations of GABAergic interneurons. Based on the weight of the postmortem and neuroimaging literature discussed herein, we favor a complex hypothesis that BD primarily constitutes a developmental disorder, but that additional, progressive, histopathological processes also are associated with recurrent or chronic illness. Conceivably BD may be best conceptualized as a progressive neurodevelopmental disorder.

Dimensional endophenotypes in bipolar disorder: affective dysregulation and psychosis proneness

BACKGROUND

The clinical phenotype of bipolar disorder (BPD) is heterogeneous and the genetic architecture of the disorder is complex and not well understood. Given these complications, it is possible that the identification of intermediate phenotypes ("endophenotypes") will be useful in elucidating the complex genetic mechanisms that result in the disorder. The examination of unaffected relatives is critical in determining whether a particular trait is genetically-relevant to BPD. However, few dimensional traits related to BPD have been assessed in unaffected relatives of patients.

METHODS

We assessed affective temperament and schizotypy in 55 discordant sibling pairs and 113 healthy controls (HCs) using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego, Auto-questionnaire version (TEMPS-A) to assess affective temperament and the Schizotypal Personality Questionnaire (SPQ) to assess schizotypy.

RESULTS

BPD patients scored significantly higher than HCs on all subscales of the SPQ and on all but one subscale (hyperthymic) of the TEMPS-A (all p<0.01). Siblings demonstrated scores that were significantly intermediate to patients and HCs on the anxious subscale of the TEMPS-A and on the interpersonal deficits and disorganized subscales of the SPQ.

LIMITATIONS

We did not investigate the BPD spectrum as most patients were diagnosed with BPD I (n=47). Most of the patients had experienced psychosis (n=42) and so we were unable to examine whether psychosis status impacted upon affective temperament or schizotypy in patients or their siblings.

CONCLUSION

These data suggest that schizotypy and affective temperament represent dimensional traits that are likely to underlie the genetic risk for BPD.

Epidemiological and clinical characterization following a first psychotic episode in major depressive disorder: comparisons with schizophrenia and bipolar I disorder in the Cavan-Monaghan First Episode Psychosis Study (CAMFEPS)

While recent research on psychotic illness has focussed on the nosological, clinical, and biological relationships between schizophrenia and bipolar disorder, little attention has been directed to the most common other psychotic diagnosis, major depressive disorder with psychotic features (MDDP). As this diagnostic category captures the confluence between dimensions of psychotic and affective psychopathology, it is of unappreciated heuristic potential to inform on the nature of psychotic illness. Therefore, the epidemiology and clinical characteristics of MDDP were compared with those of schizophrenia and bipolar disorder within the Cavan-Monaghan First Episode Psychosis Study (n = 370). Epidemiologically, the first psychotic episode of MDDP (n = 77) was uniformly distributed across the adult life span, while schizophrenia (n = 73) and bipolar disorder (n = 73) were primarily disorders of young adulthood; the incidence of MDDP, like bipolar disorder, did not differ between the sexes, while the incidence of schizophrenia was more common in males than in females. Clinically, MDDP was characterized by negative symptoms, executive dysfunction, neurological soft signs (NSS), premorbid intellectual function, premorbid adjustment, and quality of life similar to those for schizophrenia, while bipolar disorder was characterized by less prominent negative symptoms, executive dysfunction and NSS, and better quality of life. These findings suggest that what we currently categorize as MDDP may be more closely aligned with other psychotic diagnoses than has been considered previously. They indicate that differences in how psychosis is manifested vis-à-vis depression and mania may be quantitative rather than qualitative and occur within a dimensional space, rather than validating categorical distinctions.

The impact of child sexual abuse on the course of bipolar disorder: a systematic review

OBJECTIVES

The aim of this review was to elucidate the impact of child sexual abuse on all clinical phenomena that occur after the onset of bipolar disorder, including associated clinical features that are not part of the diagnostic criteria for the disorder.

METHODS

Five databases were searched and supplemented with a hand search of reference lists from retrieved papers. Study quality was assessed using a validated quality assessment tool. Blind assessments of study eligibility and quality were conducted by two independent researchers to reduce bias, minimize errors, and enhance the reliability of findings. Disagreements were resolved by consensus.

RESULTS

Eighteen studies that included a total of 2996 adults and youths with bipolar disorder and met the minimum quality criteria necessary to ensure objectivity and not invalidate results were analyzed. Across studies, child sexual abuse was strongly (and perhaps directly) associated with posttraumatic stress disorder; whereas it was less strongly (and perhaps indirectly) related to suicide attempts, alcohol and/or drug abuse or dependence, psychotic symptoms, and an early age of illness onset. In regard to the association between child sexual abuse and other clinical variables concerning the course of bipolar disorder, evidence was scant or conflicting.

CONCLUSIONS

Child sexual abuse is associated (either directly or indirectly) with some clinical phenomena that represent a more severe form of bipolar disorder. Although such a traumatic experience may directly affect the development of posttraumatic stress disorder, the effects of early sexual abuse on later suicidal behavior, substance abuse, and psychotic symptoms may operate through the mediating influences of certain psychopathological or neurobiological variables.

Neurocognitive features in subgroups of bipolar disorder

OBJECTIVE

To examine which subgroups of DSM-IV bipolar disorder (BD) [BD type I (BD-I) or BD type II (BD-II), and subgroups based on history of psychosis, presenting polarity, and age at onset] differentiate best regarding neurocognitive measures.

METHODS

A total of 199 patients with BD were characterized by clinical and neurocognitive features. The distribution of subgroups in this sample was: BD-I, 64% and BD-II, 36%; 60% had a history of psychosis; 57% had depression as the presenting polarity; 61% had an early onset of BD, 25% had a mid onset, and 14% had a late onset. We used multivariate regression analyses to assess relationships between neurocognitive variables and clinical subgroups.

RESULTS

Both BD-I diagnosis and elevated presenting polarity were related to impairments in verbal memory, with elevated presenting polarity explaining more of the variance in this cognitive domain (22.5%). History of psychosis and BD-I diagnosis were both related to impairment in semantic fluency, with history of psychosis explaining more of the variance (11.6%).

CONCLUSION

Poor performance in verbal memory appears to be associated with an elevated presenting polarity, and poor performance in semantic fluency appears to be associated with a lifetime history of psychosis.

Executive deficits in early onset bipolar disorder versus ADHD: impact of processing speed and lifetime psychosis

Executive deficits are reported in both early onset bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD), and controversies regarding comorbidity and symptom overlap have complicated the research on executive function in BD. Reports of the negative impact of executive difficulties on academic functioning indicate a need for a greater focus on executive difficulties in early onset psychiatric disorders. Executive function and processing speed in youths with BD (n = 4), ADHD (n = 26) and BD + ADHD (n = 13) were compared with controls (n = 69). All clinical groups demonstrated executive impairment. The combined group was most impaired. There were no significant differences between the groups. Executive deficit in the BD group was associated with a history of psychotic symptoms. The BD-nonpsychotic group was impaired only with regard to processing speed. Processing speed adjustment improved working memory and normalized interference control in both BD and ADHD.

CONCLUSION

executive deficits in BD may be determined by a history of psychotic symptoms rather than by comorbid ADHD. Some aspects of executive problems appear speed-related.

High prevalence of childhood trauma in patients with schizophrenia spectrum and affective disorder

OBJECTIVE

Childhood trauma (CT) is a major risk factor for various psychiatric disorders. We wanted to determine the prevalence of CT in a catchment area-based sample of schizophrenia spectrum and affective disorder (including bipolar disorder and depressive episodes with psychotic features) and to explore potential differences in types of CT between the diagnostic groups.

METHOD

Three hundred five patients were recruited consecutively from psychiatric units at 3 major hospitals in Oslo, Norway, diagnosed with Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Traumatic childhood events were assessed with Childhood Trauma Questionnaire.

RESULTS

Eighty-two percent of the patients had experienced one or more CT events, the most frequent subtype of trauma being emotional neglect. The schizophrenia spectrum group reported significantly more physical abuse and physical neglect than the affective group.

CONCLUSION

A high prevalence of CT in patients with severe mental disorder was detected. This reminds us of the importance of exploring this issue when we treat such patients. The mechanisms behind these differences are unclear. Further research is needed to study potential associations between CT and the clinical picture of the disorder.

Schizotypy and genetic loading for schizophrenia impact upon neuropsychological status in bipolar II and unipolar major depressive disorders

BACKGROUND

Growing evidence suggests that schizotypy and genetic loading for schizophrenia both represent risk for the development of schizophrenia. Although these conditions are known to be associated with neurocognitive impairments, such an association has not been studied in patients with bipolar II disorder (BPII) or unipolar major depressive disorder (UP).

METHODS

Forty-one depressed patients with BPII, 131 patients with UP and demographically matched 225 healthy controls were recruited. Schizotypy was assessed by the Schizotypal Personality Questionnaire. Neuropsychological functioning was measured by the Wechsler Memory Scale-Revised, the Wechsler Adult Intelligence Scale-Revised and the Wisconsin Card Sorting Test.

RESULTS

Mood disorder patients performed significantly worse than controls in verbal and visual memory, working memory and processing speed. BPII patients performed significantly more poorly than UP patients in verbal memory and executive functioning. Both BPII and UP patients demonstrated significantly greater schizotypal traits than controls. Schizotypy was significantly negatively correlated with verbal comprehension both in BPII and UP patients and with working memory and processing speed in healthy controls. Patients who had one or more first-degree relatives with schizophrenia performed significantly more poorly than the remaining patients in all cognitive domains.

LIMITATIONS

Most of our patients were on psychotropic medication, and the sample of BPII patients was not very large.

CONCLUSIONS

Liability for schizophrenia could play a pivotal role in neurocognitive functioning in mood disorders, suggesting that such liability might lie on a continuum ranging from normality through mood disorders to full-blown schizophrenia.

The impact of a history of psychotic symptoms on cognitive function in euthymic bipolar patients: a comparison with schizophrenic patients and healthy controls

BACKGROUND

About two-thirds of patients with bipolar disorder (BD) have a lifetime history of at least one psychotic symptom.

OBJECTIVE

To compare the neurocognitive performance of four groups: BD patients with and without a history of psychotic symptoms (BD HPS+ and BD HPS-, respectively); patients with schizophrenia (SZ); and healthy control (HC) subjects.

METHOD

In this cross-sectional study, 35 stabilized patients with SZ, 79 euthymic (44 HPS+ and 35 HPS-) patients with BD, and 50 HC were administered a comprehensive battery of neuropsychological tests.

RESULTS

There was worse neurocognitive functioning in both BD and SZ patients compared to HC. Overall, data from both groups of BD patients did not differ on sociodemographic, clinical, or neurocognitive variables. However, BD HPS+ patients had significantly more negative symptoms, as measured by the Positive and Negative Syndrome Scale (PANSS), and showed a trend toward worse performance on executive functions compared to BD HPS- patients. Moreover, both BD groups had better performance on all neurocognitive tests compared to SZ group.

CONCLUSIONS

Neurocognitive dysfunction may be more marked in SZ than in BD, yet qualitatively similar. A history of past psychotic symptoms in BD was not associated with more severe cognitive impairment during euthymia. Therefore, BD with psychotic symptoms does not appear to be a distinct neurocognitive phenotype.

Neuropsychological performance in bipolar I, bipolar II and unipolar depression patients: a longitudinal, naturalistic study

BACKGROUND

It has been suggested that cognitive deficits existed in mood disorders. Nevertheless, whether neuropsychological profiles differ three main subtypes of mood disorder (Bipolar I, Bipolar II and UP) remain understudied because most current studies include either mixed samples of bipolar I and bipolar II patients or mixed samples of different states of the illness. The main aim of the present study is to determine whether, or to some extent, specific cognitive domains could differentiate the main subtypes of mood disorders in the depressed and clinically remitted status.

METHOD

Three groups of bipolar I (n=92), bipolar II (n=131) and unipolar depression (UP) patients (n=293) were tested with a battery of neuropsychological tests both at baseline (during a depressive episode) and after 6 weeks of treatment, contrasting with 202 healthy controls on cognitive performance. The cognitive domains include processing speed, attention, memory, verbal fluency and executive function.

RESULTS

At the acute depressive state, the three patient groups (bipolar I, bipolar II and UP) showed cognitive dysfunction in processing speed, memory, verbal fluency and executive function but not in attention compared with controls. Post comparisons revealed that bipolar I depressed patients performed significantly worse in verbal fluency and executive function than bipolar II and UP depressed patients. No difference was found between bipolar II and UP depressed patients except for the visual memory. After 6 weeks of treatment, clinically remitted bipolar I and bipolar II patients only displayed cognitive impairment in processing speed and visual memory. Remitted UP patients showed cognitive impairment in executive function in addition to processing speed and visual memory. The three remitted patient groups scored similarly in processing speed and visual memory.

LIMITATION

Clinically remitted patients were just recovered from a major depressive episode after 6 weeks of treatment and in relatively unstable state.

CONCLUSION

Bipolar I, bipolar II and UP patients have a similar pattern of cognitive impairment during the state of acute depressive episode, but bipolar I patients experience greater impairment than bipolar II and UP patients. In clinical remission, both bipolar and UP patients show cognitive deficits in processing speed and visual memory, and executive dysfunction might be a status-maker for bipolar disorder, but a trait-marker for UP.

Childhood maltreatment and clinical outcomes of bipolar disorder

OBJECTIVE

Adverse life events, especially early trauma, play a major role in the course and expression of bipolar disorder (BD). The aim of this article is to present a systematic review about the impact of childhood trauma on the clinical course of BD.

METHOD

A computer-aided search was performed in Medline, ISI database, EMBASE, PsychInfo, Centre for Reviews and Dissemination, and Databases of Thomson Reuters at April 2011, supplemented by works identified from the reference lists of the first selected papers. Two investigators systematically and independently examined all articles, selecting those according inclusion and exclusion criteria.

RESULTS

Four hundred fifteen articles were identified, of which 19 remained in the review after exclusion criteria were applied. In general, childhood maltreatment predicted worsening clinical course of BD. After assessing the quality of the data and of the measurements, childhood maltreatment can be strongly associated to early onset of disorder, suicidality, and substance abuse disorder in patients with BD.

CONCLUSION

Data suggest that childhood abuse and neglect are risk factors associated with worsening clinical course of BD. The conclusions should be interpreted with caution because all the studies included are cross-sectional and the majority are showing inconsistencies regarding childhood trauma as independent variable and how it is assessed.

Neurocognitive impairment across the bipolar spectrum

Bipolar disorder is a severe mental illness that affects nearly 4.4% of the general population when bipolar spectrum disorders are taken into account. Neurocognitive impairment is thought to be a core deficit of this illness since it is present during euthymia. In fact, 40-60% of euthymic patients present with neurocognitive disturbances. Not only the clinical factors but also disturbances in neurocognition can influence the functional outcome of BD patients. Hence, further research is needed in order to clarify the relationship between these variables. Despite the growing body of evidence that has emerged during the last decade, no unique neurocognitive profile has been proposed yet for either BD subtype. The majority of the studies recluted heterogeneous samples (including both bipolar I and II) or focused on BD-I patients only. The aim of this review is to give an overall picture of the main neurocognitive disturbances found in the bipolar spectrum and particularly in BD-II, where the findings are more ambiguous. An extensive review of all the literature has been done regarding this subtype (from 1980 until July 2009). Data available until now suggest that deficits are present across the bipolar spectrum (BD-I and BD-II), but they seem slightly more severe in BD-I. The extent to which either subtype share-or not-some similarities is still unknown. More studies are required but it would also be interesting to reach a consensus in the neuropsychological assessment of BD to facilitate comparisons between the different studies.

A 2-year naturalistic study on cognitive functioning in bipolar disorder

OBJECTIVE

Cognitive alterations in bipolar disorder may reflect genetic influence. However, to what degree mood, medication, thyroid function and other factors impact on longitudinal cognitive functioning remains unclear.

METHOD

A group of patients with bipolar (spectrum) disorder (n = 76) underwent two monthly cognitive assessments over a 2-year period in a prospective, repeated measures design. Regression models were used to investigate associations with predictors, corrected for multiple testing.

RESULTS

Patients with bipolar disorder performed worse than healthy controls (n = 61) on all cognitive domains tested. Effect sizes were small, with a maximum of -0.36 for sustained attention. However, cognitive performance varied substantially over the 2-year follow-up, co-varying with subjective cognitive complaints and impacting on functioning. Alterations in sustained attention and motor speed were the only impairments that were invariant over time. Predictors had very limited explanatory power on temporal variation in cognition. Use of second-generation antipsychotics was associated with the largest negative effects on cognition, which were evident in the areas of motor speed and basic information processing (-0.35 < β < -0.5).

CONCLUSION

Cognitive function in bipolar disorder varies significantly over time, largely independent of clinical factors. The temporal stability of sustained attention is the exception, suggesting it may represent a possible candidate intermediary phenotype.

Neurocognitive markers of psychosis in bipolar disorder: a meta-analytic study

BACKGROUND

It has been suggested that patients with psychotic bipolar disorder (BDP+) might have more severe cognitive deficits than non-psychotic bipolar disorder patients (BDP-). However, only a handful of studies have compared cognition between BDP+ and BDP-. Our aim was to examine cognitive deficits associated with psychosis in BD using meta-analytic methods.

METHODS

After a systematic literature review, we conducted a meta-analysis on studies that compared cognition in bipolar disorder (BD) patients with and without a history of psychosis. In addition the effects of clinical and demographic confounder factors were examined with meta-regression analyses.

RESULTS

There were no significant differences for gender and duration of illness between groups. Compared with BDP-, BDP+ patients had more inpatient admissions, a younger onset of illness and used antipsychotics more commonly. BDP+ patients also performed significantly worse in 4 of 6 cognitive domains (planning and reasoning, working memory, verbal memory and processing speed). There were also differences for some individual tasks (List Learning, Delayed Recall, Trail Making B, Wisconsin Card Sorting Test, Digits Backwards, Stroop Interference, Semantic Fluency) with BDP+ patients showing moderately greater impairment on these tasks (d=0.30-0.55).

CONCLUSIONS

A history of psychosis is associated with greater severity of cognitive deficits in BD. However, this effect is modest, and these findings do not suggest a complete categorical distinction between BDP+ and BDP-. Psychosis in BD might reflect partly distinct neurobiological processes.

The International Society for Bipolar Disorders-Battery for Assessment of Neurocognition (ISBD-BANC)

OBJECTIVES

Although cognitive impairment is recognized as an important clinical feature of bipolar disorder, there is no standard cognitive battery that has been developed for use in bipolar disorder research. The aims of this paper were to identify the cognitive measures from the literature that show the greatest magnitude of impairment in bipolar disorder, to use this information to determine whether the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB), developed for use in schizophrenia, might be suitable for bipolar disorder research, and to propose a preliminary battery of cognitive tests for use in bipolar disorder research.

METHODS

The project was conducted under the auspices of the International Society for Bipolar Disorders and involved a committee that comprised researchers with international expertise in the cognitive aspects of bipolar disorder. In order to identify cognitive tasks that show the largest magnitude of impairment in bipolar disorder, we reviewed the literature on studies assessing cognitive functioning (including social cognition) in bipolar disorder. We further provided a brief review of the cognitive overlap between schizophrenia and bipolar disorder and evaluated the degree to which tasks included in the MCCB (or other identified tasks) might be suitable for use in bipolar disorder.

RESULTS

Based on evidence that cognitive deficits in bipolar disorder are similar in pattern but less severe than in schizophrenia, it was judged that most subtests comprising the MCCB appear appropriate for use in bipolar disorder. In addition to MCCB tests, other specific measures of more complex verbal learning (e.g., the California Verbal Learning Test) or executive function (Stroop Test, Trail Making Test-part B, Wisconsin Card Sorting Test) also show substantial impairment in bipolar disorder.

CONCLUSIONS

Our analysis reveals that the MCCB represents a good starting point for assessing cognitive deficits in research studies of bipolar disorder, but that other tasks including more complex verbal learning measures and tests of executive function should also be considered in assessing cognitive compromise in bipolar disorder. Several promising cognitive tasks that require further study in bipolar disorder are also presented.

Amygdala volume in depressed patients with bipolar disorder assessed using high resolution 3T MRI: the impact of medication

MRI-based reports of both abnormally increased and decreased amygdala volume in bipolar disorder (BD) have surfaced in the literature. Two major methodological weaknesses characterizing extant studies are treatment with medication and inaccurate segmentation of the amygdala due to limitations in spatial and tissue contrast resolution. Here, we acquired high-resolution images (voxel size=0.55 x 0.55 x 0.60 mm) using a GE 3T MRI scanner, and a pulse sequence optimized for tissue contrast resolution. The amygdala was manually segmented by one rater blind to diagnosis, using coronal images. Eighteen unmedicated (mean medication-free period 11+/-10 months) BD subjects were age and gender matched with 18 healthy controls, and 17 medicated (lithium or divalproex) subjects were matched to 17 different controls. The unmedicated BD patients displayed smaller left and right amygdala volumes than their matched control group (p<0.01). Conversely, the BD subjects undergoing medication treatment showed a trend towards greater amygdala volumes than their matched HC sample (p=0.051). Right and left amygdala volumes were larger (p<0.05) or trended larger, respectively, in the medicated BD sample compared with the unmedicated BD sample. The two control groups did not differ from each other in either left or right amygdala volume. BD patients treated with lithium have displayed increased gray matter volume of the cortex and hippocampus relative to untreated BD subjects in previous studies. Here we extend these results to the amygdala. We raise the possibility that neuroplastic changes in the amygdala associated with BD are moderated by some mood stabilizing medications.

Bipolar and major depressive disorder: neuroimaging the developmental-degenerative divide

Both major depressive disorder and bipolar disorder are the subject of a voluminous imaging and genetics literature. Here, we attempt a comprehensive review of MRI and metabolic PET studies conducted to date on these two disorders, and interpret our findings from the perspective of developmental and degenerative models of illness. Elevated activity and volume loss of the hippocampus, orbital and ventral prefrontal cortex are recurrent themes in the literature. In contrast, dorsal aspects of the PFC tend to display hypometabolism. Ventriculomegaly and white matter hyperintensities are intimately associated with depression in elderly populations and likely have a vascular origin. Important confounding influences are medication, phenotypic and genetic heterogeneity, and technological limitations. We suggest that environmental stress and genetic risk variants interact with each other in a complex manner to alter neural circuitry and precipitate illness. Imaging genetic approaches hold out promise for advancing our understanding of affective illness.