Cognitive function across manic or hypomanic, depressed, and euthymic states in bipolar disorder

Impact of number of episodes on neurocognitive trajectory in bipolar disorder patients: a 5-year follow-up study

BACKGROUND

The neurocognitive trajectory in bipolar disorder (BD) is variable, with controversial findings, and most evidence come from cross-sectional studies. We aimed to examine the course of neurocognitive functioning in a sample of euthymic BD patients in comparison with a control group during a 5-year follow-up.

METHODS

Ninety-nine euthymic bipolar patients and 40 healthy controls were assessed using a comprehensive neurocognitive battery (six neurocognitive domains) at baseline (T1) and then at 5-year follow-up (T2) in a longitudinal study.

RESULTS

No evidence of a progression in neurocognitive dysfunction was found either in cognitive composite index or in any of the neurocognitive domains for the whole cohort. However, there was a negative correlation between number of manic episodes and hospitalisations due to manic episodes and change in neurocognitive composite index (NCI) during the follow-up. Moreover, patients with higher number of manic and hypomanic episodes have a greater decrease in NCI, working memory and visual memory. History of psychotic symptoms was not related to the trajectory of neurocognitive impairment.

CONCLUSIONS

Our results suggest that, although the progression of cognitive decline is not a general rule in BD, BD patients who have a greater number of manic or hypomanic episodes may constitute a subgroup characterised by the progression of neurocognitive impairment. Prevention of manic and hypomanic episodes could have a positive impact on the trajectory of cognitive function.

A case-control study of paternal and maternal age as risk factors in mood disorders

Objective: Advanced parental age might constitute a risk factor for various disorders. We tested whether this concerns also mood disorder patients. Methods: The study included 314 subjects (42 bipolar-BD patients; 21 manics and 21 depressives, 68 unipolar-UD, and 204 normal controls-NC). Analysis of Covariance (ANCOVA) and the calculation of the Relative Risk (RR) and the Odds Ratio (OR) were used for the analysis. Results: Paternal age differed between NC and UD patients (29.42 ± 6.07 vs. 32.12 ± 5.54; p = .01) and manics (29.42 ± 6.07 vs. 35.00 ± 5.75; p = .001) and maternal age between NC and manics (25.46 ± 4.52 vs. 31.43 ± 4.75; p < .001) and manic and UD (31.43 ± 4.75 vs. 26.75 ± 6.03; p = .002). The RR and OR values suggested that advanced parental age constitutes a risk factor for the development of mood disorders. Conclusions: In a non-dose dependent and gender-independent, advanced parental age constitutes a risk factor for the development of BD with index episode of mania (probably manic predominant polarity); only advanced paternal age constitutes a risk factor for the development of UD and BD with index episode of depression (probably depressive predominant polarity). This is the first study suggesting differential effect of advanced parental age depending on predominant polarity of BD.

Predominant polarity in bipolar disorder patients: The COPE bipolar sample

BACKGROUND

The concept of predominant polarity (PP) is defined as presenting more symptoms of one polarity. Previous studies have defined PP as one polarity (either a depression or mania episode) occurring during at least two-thirds of the lifetime.

METHODS

We conducted an observational study with the COPE-BD (Clinical Outcome and Psycho-Education for Bipolar Disorder, Clinical Outcome Measures Section) dataset to identify the diagnostic and treatment differences between bipolar disorder (BD) patients with and without PP.

RESULTS

The final sample included 210 BD-I (59.0%) and 146 BD-II (41.0%) patients. Of these, 28.9% patients presented predominant polarity (PP): 62 (17.4%) of those patients were depressed polarity predominant (DPP), 41 (11.5%) were manic polarity predominant (MPP), and 253 (71.1%) met criteria for bipolar disorders but did not present with PP. In comparison to this group of BD patients with undetermined polarity, the group of BD patients with PP presented more rapid cycling. Furthermore, in the undetermined polarity group, the onset of illness occurred earlier, and the duration of the illness was longer, with more hypomanic/manic and depressive episodes than patients who met the PP criteria.

LIMITATIONS

This study has a naturalistic and retrospective design and does not allow a specific follow-up of polarity over time.

CONCLUSIONS

These different clinical characteristics underline the importance of considering PP in patients with BD, and justify the need for differential treatment approach which could have an impact on patients' prognosis. Yet, more independent and prospective research is needed to confirm these findings, especially with the new classification of DSM-5 concerning mixed states.

Functional outcome assessment in bipolar disorder: A systematic literature review

OBJECTIVES

Functional impairment is an important driver of disability in patients with bipolar disorder (BD) and can persist even when symptomatic remission has been achieved. The objectives of this systematic literature review were to identify studies that assessed functioning in patients with BD and describe the functional scales used and their implementation.

METHODS

A systematic literature review of English-language articles published between 2000 and 2017 reporting peer-reviewed, original research related to functional assessment in patients with BD was conducted.

RESULTS

A total of 40 articles met inclusion criteria. Twenty-four different functional scales were identified, including 13 clinician-rated scales, 7 self-reported scales, and 4 indices based on residential and vocational data. The Global Assessment of Functioning (GAF) and the Functional Assessment Short Test (FAST) were the most commonly used global and domain-specific scales, respectively. All other scales were used in ≤2 studies. Most studies used ≥1 domain-specific scale. The most common applications of functional scales in these studies were evaluations of the relationships between global or domain-specific psychosocial functioning and cognitive functioning (eg, executive function, attention, language, learning, memory) or clinical variables (eg, symptoms, duration of illness, number of hospitalizations, number of episodes).

CONCLUSIONS

The results of this review show growing interest in the assessment of functioning in patients with BD, with an emphasis on specific domains such as work/educational, social, family, and cognitive functioning and high utilization of the GAF and FAST scales in published literature.

Differential effects of unipolar versus bipolar depression on episodic memory updating

Episodic memories, when reactivated, can be modified or updated by new learning. Since such dynamic memory processes remain largely unexplored in psychiatric disorders, we examined the impact of depression on episodic memory updating. Unipolar and bipolar depression patients, and age/education matched controls, first learned a set of objects (List-1). Two days later, participants in all three groups were either reminded of the first learning session or not followed by the learning of a new set of objects (List-2). Forty-eight hours later, List-1 recall was impaired in unipolar and bipolar patients compared to control participants. Further, as expected, control participants who received a reminder spontaneously recalled items from List-2 during recall of List-1, indicative of an updated List-1 memory. Such spontaneous intrusions were also seen in the unipolar and bipolar patients that received the reminder, suggesting that memory updating was unaffected in these two patient groups despite impaired recall of List 1. Unexpectedly, we observed a trend towards higher intrusions, albeit statistically insignificant, not only in the reminder but also in the no-reminder subgroups of bipolar patients. We probed this further in a second cohort by testing recall of List-2, which was also impaired in both depression groups. Again bipolar patients showed intrusions, but this time in the reverse order from List-1 into List-2, independent of a reminder. Taken together, despite impaired recall, updating of episodic memories was intact and unidirectional in unipolar depression. In contrast, indiscriminate updating, as evidenced by bidirectional interference between episodic memories, was seen in bipolar depression. These findings reveal a novel distinction between unipolar versus bipolar depression using a reactivation-dependent memory updating paradigm.

Improving Functioning, Quality of Life, and Well-being in Patients With Bipolar Disorder

People with bipolar disorder frequently experience persistent residual symptoms, problems in psychosocial functioning, cognitive impairment, and poor quality of life. In the last decade, the treatment target in clinical and research settings has focused not only on clinical remission, but also on functional recovery and, more lately, in personal recovery, taking into account patients' well-being and quality of life. Hence, the trend in psychiatry and psychology is to treat bipolar disorder in an integrative and holistic manner. This literature review offers an overview regarding psychosocial functioning in bipolar disorder. First, a brief summary is provided regarding the definition of psychosocial functioning and the tools to measure it. Then, the most reported variables influencing the functional outcome in patients with bipolar disorder are listed. Thereafter, we include a section discussing therapies with proven efficacy at enhancing functional outcomes. Other possible therapies that could be useful to prevent functional decline and improve functioning are presented in another section. Finally, in the last part of this review, different interventions directed to improve patients' well-being, quality of life, and personal recovery are briefly described.

The associations between subjective and objective cognitive functioning across manic or hypomanic, depressed, and euthymic states in Chinese bipolar patients

BACKGROUND

Patients may present cognitive deficits during all stages of bipolar disorder (BD). Few studies have examined self-reported cognitive difficulties and its relation to neurocognitive dysfunction during symptomatic periods of BD. This study aimed to compare subjective cognitive functioning and explore associations between subjective and objective cognitive functioning across different BD clinical states, and investigate the predicting and moderating roles of mood symptoms.

METHODS

Subjective cognitive functioning (measured by Cognitive Complaints in Bipolar Disorder Rating Assessment, COBRA) and several domains of cognitive functioning (assessed by a neuropsychological battery), including executive functions, attention and processing speed, and visual memory, were examined in 48 hypomanic or manic patients, 42 depressed bipolar patients, 50 euthymic bipolar patients and 60 healthy comparisons.

RESULTS

All patients exhibited subjective and objective cognitive deficits in relation to healthy comparisons. There was a significant association between subjective and objective cognitive functioning in euthymic group, but the association was not significant in acute symptomatic groups, which could be moderated by depressive or manic symptoms in depressive or manic group, respectively. Subjective cognitive functioning was significantly correlated with mood symptoms, and the best predictor of subjective cognitive functioning was depressive symptoms.

LIMITATIONS

This was a cross-sectional study with a mixed sample of inpatients and outpatients. The medication effect was not adjusted.

CONCLUSIONS

The associations between subjective and objective cognitive dysfunction varied in clinical states, and mood symptoms moderated the associations. A neuropsychological test battery is required to substantiate actual cognitive dysfunction in clinical settings, irrespective of subjective cognitive deficits.

Effects of illness duration on cognitive performances in bipolar depression are mediated by white matter microstructure

BACKGROUND

Cognitive deficits are a core feature of bipolar disorder (BD), and persist during the euthymic phase. White matter (WM) microstructural abnormalities are widely considered a structural marker of BD. Features of illness chronicity, such as illness duration and number of mood episodes, have been associated with worsening of both clinical profile and brain structural alterations. This study examined the role of WM integrity as a possible mediator between illness duration and cognitive performances in a sample of BD patients.

METHODS

We assessed 88 inpatients affected by a depressive episode in course of type I BD for verbal memory, visual memory, working memory, visuospatial constructional abilities, psychomotor coordination, executive functions, processing speed, and verbal fluency. White matter integrity was evaluated through FA measurements derived using the Enhancing Neuro Imaging Genetics Through Meta-Analysis (ENIGMA)-DTI protocol.

RESULTS

The effect of illness duration on processing speed, verbal memory, and visual memory was mediated by the FA values of bilateral anterior corona radiata, bilateral corona radiata, genu of corpus callosum, and fornix, adjusting for age, sex, education and lithium treatment (p < 0.05).

LIMITATIONS

Potential interaction factors were not examined in this study.

CONCLUSIONS

This is the first study to show the role of WM integrity as a mediator of the negative effect of illness duration on cognitive performances. Our data provide new insight into the neuroprogressive hypothesis of BD.

The Role of Docosahexaenoic Acid (DHA) on Cognitive Functions in Psychiatric Disorders

Cognitive impairment is strongly associated with functional outcomes in psychiatric patients. Involvement of n-3 long chain polyunsaturated fatty acid (n-3 LC-PUFA), in particular docosahexaenoic acid (DHA), in brain functions is largely documented. DHA is incorporated into membrane phospholipids as structural component, especially in the central nervous system where it also has important functional effects. The aim of this review is to investigate the relationship between DHA and cognitive function in relation to mental disorders. Results from few randomized controlled trials (RCTs) on the effects of DHA (alone or in combination) in psychotic, mood and neurodevelopmental disorders, respectively, suggest that no conclusive remarks can be drawn.

Adjunctive tianeptine treatment for bipolar disorder: A 24-week randomized, placebo-controlled, maintenance trial

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of tianeptine as an adjunctive maintenance treatment for bipolar depression.

METHODS

This is a multicenter double-blind randomized placebo-controlled maintenance trial of adjunctive tianeptine 37.5 mg/day. Participants ( n=161) had a Montgomery-Asberg Depression Rating Scale ⩾12 at entry. After eight weeks of open-label tianeptine treatment, those who responded to tianeptine ( n=69) were randomized to adjunctive tianeptine ( n=36) or placebo ( n=33) in addition to usual treatment. Kaplan-Meier estimates and the Mantel-Cox log-rank test were used to evaluate differences in time to intervention for a mood episode between the tianeptine and placebo groups. We also assessed overall functioning, biological rhythms, quality of life, rates of manic switch and serum brain-derived neurotrophic factor levels.

RESULTS

There were no differences between adjunctive tianeptine or placebo regarding time to intervention or depression scores in the 24-week double-blind controlled phase. Patients in the tianeptine group showed better performance in the letter-number sequencing subtest from the Wechsler Adult Intelligence Scale at the endpoint ( p=0.014). Tianeptine was well tolerated and not associated with higher risk for manic switch compared to placebo.

CONCLUSION

Tianeptine was not more effective than placebo in the maintenance treatment of bipolar depression. There is preliminary evidence suggesting a pro-cognitive effect of tianeptine in working memory compared to placebo.

Cognitive variability in bipolar I disorder: A cluster-analytic approach informed by resting-state data

BACKGROUND

While the presence of cognitive performance deficits in bipolar disorder I (BD-I) is well established, there is no consensus about which cognitive abilities are affected. Heterogeneous phenotypes displayed in BD-I further suggest the existence of subgroups among the disorder. The present study sought to identify different cognitive profiles among BD-I patients as well as potentially underlying neuronal network changes.

METHODS

54 euthymic BD-I patients underwent cognitive testing and resting state neuroimaging. Hierarchical cluster-analysis was performed on executive function scores of bipolar patients. The derived clusters were compared against 54 age-, gender- and IQ-matched healthy controls (HC) to facilitate the interpretation of results. Further, resting state network properties were compared to identify differences probably underlying cognitive profiles.

RESULTS

A three-cluster solution emerged. Cluster 1 (n = 22) was characterized by deficits in cognitive flexibility and motor inhibition, cluster 2 (n = 12) displayed impulsive decision-making, while cluster 3 (n = 20) showed good visuospatial planning. Weaker connections in cluster 1 compared to cluster 2 were found between regions activated during tasks cluster 1 showed deficits on. Cluster 3 had a higher modularity than cluster 2, which correlated positively with problem solving performance and risk-taking in this cluster.

CONCLUSION

Obtained clusters showed distinct cognitive profiles, characterized by deficits and strengths, most of which remained precluded in a general comparison. Weaker interregional connections and separated subnetworks might underly behavioral deficits and strengths, respectively. The findings help explain the phenotypic heterogeneity observed in BD-I. This article is part of the Special Issue entitled 'Current status of the neurobiology of aggression and impulsivity'.

The use of component-wise gradient boosting to assess the possible role of cognitive measures as markers of vulnerability to pediatric bipolar disorder

BACKGROUND AND AIMS

Cognitive impairments are primary hallmarks symptoms of bipolar disorder (BD). Whether these deficits are markers of vulnerability or symptoms of the disease is still unclear. This study used a component-wise gradient (CGB) machine learning algorithm to identify cognitive measures that could accurately differentiate pediatric BD, unaffected offspring of BD parents, and healthy controls.

METHODS

59 healthy controls (HC; 11.19 ± 3.15 yo; 30 girls), 119 children and adolescents with BD (13.31 ± 3.02 yo, 52 girls) and 49 unaffected offspring of BD parents (UO; 9.36 ± 3.18 yo; 22 girls) completed the CANTAB cognitive battery.

RESULTS

CGB achieved accuracy of 73.2% and an AUROC of 0.785 in classifying individuals as either BD or non-BD on a dataset held out for validation for testing. The strongest cognitive predictors of BD were measures of processing speed and affective processing. Measures of cognition did not differentiate between UO and HC.

CONCLUSIONS

Alterations in processing speed and affective processing are markers of BD in pediatric populations. Longitudinal studies should determine whether UO with a cognitive profile similar to that of HC are at less or equal risk for mood disorders. Future studies should include relevant measures for BD such as verbal memory and genetic risk scores.

Premorbid adjustment trajectories in schizophrenia and bipolar disorder: A transdiagnostic cluster analysis

Despite the overlap between schizophrenia and bipolar disorder, neurodevelopmental abnormalities are thought to be associated primarily with schizophrenia. Transdiagnostic and empirical identification of subgroups based on premorbid adjustment (PMA) may enhance understanding of illness trajectories. 160 patients with bipolar I or II disorder (BD; n = 104) or schizophrenia or schizoaffective disorder (SZ; n = 56) were assessed on PMA course from childhood to late adolescence and current symptoms and functioning. A hierarchical cluster analysis was performed using social and academic PMA scores, resulting in three optimal clusters. Cluster 1 (n = 28 SZ, 65 BD) had normal social and academic PMA, the most education, and mildest current symptoms. Cluster 2 (n = 15 SZ, 24 BD) had normal social PMA but an impaired-declining academic course and had a greater proportion of males than Cluster 1. Cluster 3 (n = 13 SZ, 15 BD) had an impaired-stable social PMA and an impaired-declining academic course and the most severe current negative symptoms and childhood trauma. The proportions of SZ and BD diagnoses, current neurocognition, and functioning did not differ between clusters. These findings suggest shared neurodevelopmental abnormalities between SZ and BD, with subgroups exhibiting distinct PMA trajectories that cut across disorders.

A systematic review on neuropsychological function in bipolar disorders type I and II and subthreshold bipolar disorders-something to think about

Neuropsychological dysfunction is a well-established finding in individuals with bipolar disorder type I (BP-I), even during euthymic periods; however, it is less clear whether this also pertains to bipolar disorder type II (BP-II) or those with subthreshold states (SBP; subthreshold bipolar disorder), such as bipolar not otherwise specified (BP-NOS). Herein, we compare the literature regarding neuropsychological performance in BP-II vs BP-I to determine the extent of relative impairment, and we present and review all related studies on cognition in SBP. After systematically searching PubMed, Medline, PsycINFO, and The Cochrane Library, we found 17 papers that comprise all the published studies relevant for this review. The areas that are consistently found to be impaired in BP are executive function, verbal memory, visual spatial working memory, and attention. More studies than not show no significant difference between BP-I and BP-II, particularly in euthymic samples. Preliminary evidence suggests that patients experiencing major depressive episodes who also meet criteria for SBP show similar profiles to BP-II; however, these results pertain only to a depressed sample. SBP were found to perform significantly better than both MDD and healthy controls in a euthymic sample. A consensus on mood state, patient selection, and neuropsychological testing needs to be agreed on for future research. Furthermore, no studies have used the most recent DSM-5 criteria for SBP; future studies should address this. Finally, the underlying bases of cognitive dysfunction in these diagnostic groups need to be further investigated. We suggest recommendations on all of the above current research challenges.

Associations between cognitive impairment and quality of life in euthymic bipolar patients

During the euthymic state in bipolar disorder, cognitive functions often remain affected. Specifically, subjective and objective cognitive impairment might distinctly affect patients' quality of life (QoL); however, this question had not been examined previously in Japanese patients. Therefore, the current study investigated the associations between cognitive complaints, QoL, and objective cognitive functions. Forty patients in remission were recruited from the Hokkaido University Hospital, Sapporo, Japan and assessed with the translated version of the cognitive complaints in bipolar disorder rating assessment (COBRA), medical outcomes study 36-item short-form health survey version 2 (SF-36v2), and Sheehan disability scale (SDS). The Japanese adult reading scale, Wisconsin card sorting test, word fluency, continuous performance test, trail making test (TMT), auditory verbal learning, and Stroop test evaluated objective cognitive functions. Significant correlations were observed between the COBRA, SF-36v2, and SDS results, as well as the TMT scores. Overall, euthymic patients were aware of their cognitive dysfunction, which could be understood in relation to the decrease in satisfaction in their daily life. Therefore, even mild cognitive impairments can have ramifications for patients in the euthymic state of bipolar disorder.

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.

Abnormal Degree Centrality Associated With Cognitive Dysfunctions in Early Bipolar Disorder

Delayed diagnosis of bipolar disorder (BD) is common. However, diagnostic validity may be enhanced using reliable neurobiological markers for BD. Degree centrality (DC) is one such potential marker that enables researchers to visualize neuronal network abnormalities in the early stages of some neuropsychiatric disorders. In the present study, we measured resting-state DC abnormalities and cognitive deficits in order to identify early neurobiological markers for BD. We recruited 23 patients with BD who had recently experienced manic episodes (duration of illness <2 years) and 46 matched healthy controls. Our findings indicated that patients with BD exhibited DC abnormalities in frontal areas, temporal areas, the right postcentral gyrus, and the posterior lobe of the cerebellum. Moreover, correlation analysis revealed that psychomotor speed indicators were associated with DC in the superior temporal and inferior temporal gyri, while attention indicators were associated with DC in the inferior temporal gyrus, in patients with early BD. Our findings suggest that DC abnormalities in neural emotion regulation circuits are present in patients with early BD, and that correlations between attention/psychomotor speed deficits and temporal DC abnormalities may represent early markers of BD.

Psychoradiologic abnormalities of white matter in patients with bipolar disorder: diffusion tensor imaging studies using tract-based spatial statistics

BACKGROUND

An increasing number of psychoradiology studies that use tract-based spatial statistics (TBSS) of diffusion tensor imaging have reported abnormalities of white matter in patients with bipolar disorder; however, robust conclusions have proven elusive, especially considering some important clinical and demographic factors. In the present study, we performed a quantitative meta-analysis of TBSS studies to elucidate the most consistent white-matter abnormalities in patients with bipolar disorder.

METHODS

We conducted a systematic search up to May 2017 for all TBSS studies comparing fractional anisotropy (FA) between patients with bipolar disorder and healthy controls. We performed anisotropic effect size–signed differential mapping meta-analysis.

RESULTS

We identified a total of 22 data sets including 556 patients with bipolar disorder and 623 healthy controls. We found significant FA reductions in the genu and body of the corpus callosum in patients with bipolar disorder relative to healthy controls. No regions of increased FA were reported. In subgroup analyses, the FA reduction in the genu of the corpus callosum retained significance in patients with bipolar disorder type I, and the FA reduction in the body of the corpus callosum retained significance in euthymic patients with bipolar disorder. Meta-regression analysis revealed that the percentage of female patients was negatively correlated with reduced FA in the body of the corpus callosum.

LIMITATIONS

Data acquisition, patient characteristics and clinical variables in the included studies were heterogeneous. The small number of diffusion tensor imaging studies using TBSS in patients with bipolar disorder type II, as well as the lack of other clinical information, hindered the application of subgroup meta-analyses.

CONCLUSION

Our study consistently identified decreased FA in the genu and body of the corpus callosum, suggesting that interhemispheric communication may be the connectivity most affected in patients with bipolar disorder.

The Relationship Between Cognitive Dysfunction and Symptom Dimensions Across Schizophrenia, Bipolar Disorder, and Major Depressive Disorder

Background: Cognitive dysfunction is considered a core feature among schizophrenia (SZ), bipolar disorder (BD), and major depressive disorder (MDD). Despite abundant literature comparing cognitive dysfunction among these disorders, the relationship between cognitive dysfunction and symptom dimensions remains unclear. The study aims are a) to identify the factor structure of the BPRS-18 and b) to examine the relationship between symptom domains and cognitive function across SZ, BD, and MDD. Methods: A total of 716 participants [262 with SZ, 104 with BD, 101 with MDD, and 249 healthy controls (HC)] were included in the study. One hundred eighty participants (59 with SZ, 23 with BD, 24 with MDD, and 74 HC) completed the MATRICS Consensus Cognitive Battery (MCCB), and 507 participants (85 with SZ, 89 with BD, 90 with MDD, and 243 HC) completed the Wisconsin Card Sorting Test (WCST). All patients completed the Brief Psychiatric Rating Scale (BPRS). Results: We identified five BPRS exploratory factor analysis (EFA) factors ("affective symptoms," "psychosis," "negative/disorganized symptoms," "activation," and "noncooperation") and found cognitive dysfunction in all of the participant groups with psychiatric disorders. Negative/disorganized symptoms were the most strongly associated with cognitive dysfunctions across SZ, BD, and MDD. Conclusions: Our findings suggest that cognitive dysfunction severity relates to the negative/disorganized symptom domain across SZ, BD, and MDD, and negative/disorganized symptoms may be an important target for effective cognitive remediation in SZ, BD, and MDD.

OpenSIMPLe: A real-world implementation feasibility study of a smartphone-based psychoeducation programme for bipolar disorder

BACKGROUND

Few evidence-based mental health apps are widely available to patients and, conversely, many of the available apps have not been appropriately evaluated. Given that the ultimate goal is to scale-up and open internet-based platforms (IBP), it is crucial to appropriately evaluate their real-world feasibility beforehand. We aimed to evaluate the implementation feasibility of a smartphone-based psychoeducational programme for bipolar disorder, exploring its long-term retention, usability, perceived helpfulness and satisfaction, alongside its impact on secondary health outcomes.

METHODS

Participants were recruited via the project website after completing an online screening questionnaire. They were requested to complete web-based questionnaires before using the app and after 6 months of use which included sociodemographic, illness and treatment variables, the world health organisation-five well-being index (WHO-5) and the short form health survey (SF-36). The follow-up questionnaires also contained satisfaction and usefulness questions.

RESULTS

201 participants took part in the study. According to their retention, 66.2% of the participants were classified as noncompleters and 33.8% as completers. The only predictor significantly associated with higher odds of retention was older age (OR = 1.021, p < 0.001). 62% of the users reported they were satisfied with the programme with a higher percentage among completers. Who-5 baseline and follow-up scores showed a significant improvement as well as 6 out of 8 domains of the SF-36.

LIMITATIONS

Screening and outcome measures were administered using exclusively self-reported online methods.

CONCLUSION

The 6-month attrition rate of the programme was high. Positive outcomes regarding satisfaction were found predominantly among completers. The optimal dosage and retention of IBP mental health programmes remain challenging issues that need further research.

Long-term Sustained Cognitive Benefits of Vagus Nerve Stimulation in Refractory Depression

BACKGROUND

Treatment-resistant depression (TRD) is a serious chronic condition disabling patients functionally and cognitively. Chronic vagus nerve stimulation (VNS) is recognized for the management of TRD, but few studies have examined its long-term effects on cognitive dysfunction in unipolar and bipolar resistant depression.

OBJECTIVE

The purpose of this study was to assess the course of cognitive functions and clinical symptoms in a cohort of patients treated with VNS for TRD.

METHODS

In 14 TRD patients with VNS, standardized clinical and neuropsychological measures covering memory, attention/executive functions, and psychomotor speed were analyzed prestimulation and up to 2 years poststimulation.

RESULTS

Vagus nerve stimulation patients significantly improved on cognitive and clinical measures. Learning and memory improved rapidly after 1 month of stimulation, and other cognitive functions improved gradually over time. Cognitive improvements were sustained up to 2 years of treatment. At 1 month, improvement in Montgomery-Åsberg Depression Rating Scale scores was not correlated with changes in any of the cognitive scores, whereas at 12 months, the change in Montgomery-Åsberg Depression Rating Scale score was significantly correlated with several measures (Stroop interference, verbal fluency, and Rey-Osterrieth Complex Figure delayed recall).

CONCLUSIONS

In recent years, a growing interest in cognitive dysfunction in depression has emerged. Our results suggest that chronic VNS produces sustained clinical and cognitive improvements in TRD patients, with some mental functions improving as soon as 1 month after the initiation of the VNS therapy. Vagus nerve stimulation seems a very promising adjunctive therapy for TRD patients with cognitive impairment.

Memory Impairment and Plasma BDNF Correlates of the BDNF Val66Met Polymorphism in Patients With Bipolar II Disorder

Studies suggest that a functional polymorphism of brain-derived neurotrophic factor (BDNF), polymorphism BDNF Val⁶⁶Met affects cognitive functions, however, the effect is unclear in bipolar II (BD-II) disorder. We used the Wechsler Memory Scale-third edition (WMS-III), the presence of the BDNF Val⁶⁶Met polymorphism, and plasma concentrations of BDNF to investigate the association between memory impairment and BDNF in BD-II disorder. We assessed the memory functions of 228 BD-II patients and 135 healthy controls (HCs). BD-II patients had significantly lower scores on five of the eight WMS-III subscales. In addition to education, the BDNF polymorphism were associated with the following subscales of WMS-III, auditory delayed memory, auditory delayed recognition memory and general memory scores in BD-II patients, but not in HC. Moreover, BD-II patients with the Val-homozygote scored significantly higher on the visual immediate memory subscale than did those with the Met/Met and Val/Met polymorphisms. The significantly positive effect of the Val-homozygote did not have a significantly positive effect on memory in the HC group, however. We found no significant association between BDNF polymorphisms and plasma concentrations of BDNF. The plasma BDNF was more likely to be associated with clinical characteristics than it was with memory indices in the BD-II group. The impaired memory function in BD-II patients might be dependent upon the association between the BDNF Val⁶⁶Met polymorphism and peripheral BDNF levels.

Cognitive and functional deficits in bipolar disorder and schizophrenia as a function of the presence and history of psychosis

OBJECTIVES

Schizophrenia and bipolar disorder overlap considerably. Schizophrenia is a primary psychotic disorder, whereas approximately half of people with bipolar disorder will experience psychosis. In this study, we examined the extent to which cognitive and functional impairments are related to the presence and history of psychosis across the two disorders.

METHOD

A total of 633 participants with bipolar disorder I, schizophrenia, and schizoaffective disorder were recruited for a study on the genetics of cognition and functioning in bipolar disorder and schizophrenia. Participants were classified into five groups: bipolar disorder with current psychosis (N = 30), bipolar disorder with a history of psychosis (N = 162), bipolar disorder with no history of psychosis (N = 92), schizophrenia with current psychosis (N = 245), and schizophrenia with past psychosis (N = 104).

RESULTS

Cognitive profiles of all groups were similar in pattern; however, both current psychosis (P < .02) and a diagnosis of schizophrenia (P < .03) were associated with greater impairment. Schizophrenia with current psychosis was also associated with a superimposed severe impairment in processing speed. Both psychosis (P < .03) and schizophrenia diagnosis (P < .01) were associated with poorer functional competence. Individuals with bipolar disorder and schizophrenia experienced similar impairments in real-world functioning if they were experiencing current psychosis (P = .32).

CONCLUSION

The presence of active psychosis is an important cross-diagnostic factor in cognition and functioning in both schizophrenia and bipolar disorder. Characterization and treatment of cognition and functional deficits in bipolar disorder should consider the effects of both current and history of psychosis.

Altered ErbB4 splicing and cortical parvalbumin interneuron dysfunction in schizophrenia and mood disorders

Working memory requires the activity of parvalbumin (PV) interneurons in the dorsolateral prefrontal cortex (DLPFC). Impaired working memory and lower PV expression in the DLPFC are reported in schizophrenia and to a lesser degree in mood disorders. We previously proposed that activity-dependent PV expression is lower in schizophrenia due to a shift in the splicing of erb-b2 receptor tyrosine kinase 4 (ErbB4) transcripts from major to inactive minor variants that reduces excitatory drive to PV interneurons. Here, we tested the hypothesis that the degree of major-to-minor shift in ErbB4 splicing predicts the level of PV expression across schizophrenia and mood disorders. Levels of ErbB4 splice variants and PV mRNA were quantified by PCR in the DLPFC from 40 matched tetrads (N = 160 subjects) of schizophrenia, bipolar disorder (BD), major depressive disorder (MDD), and unaffected comparison subjects. Relative to unaffected comparison subjects, the magnitude of increases in minor variant levels and decreases in major variant levels was greatest in schizophrenia, intermediate in BD, and least in MDD. The same rank order was present for the magnitude of increases in the composite splicing score, which reflects the degree of major-to-minor shift across all ErbB4 splice loci, and for the magnitude of deficient PV expression. Finally, the composite splicing score negatively predicted PV expression across all subject groups. Together, these findings demonstrate a shared relationship between ErbB4 splicing and PV expression and suggest that scaling of the major-to-minor shift in ErbB4 splicing may influence the severity of deficient PV interneuron activity across diagnoses.

The clinical relationship between cognitive impairment and psychosocial functioning in major depressive disorder: A systematic review

Cognitive deficits are frequently observed in major depressive disorder (MDD), as well as impaired long-term psychosocial functioning. However, the relationship between cognitive deficits and psychosocial functioning in MDD is under-investigated. We aim to systematically review the literature on the relationship between specific cognitive impairments and psychosocial functioning in MDD. We systematically reviewed English-language literature in PubMed, PsychINFO, Scopus and Web of Science using search terms related to psychosocial functioning. Additional studies were identified by searching reference lists. Following our inclusion/exclusion criteria, 28 studies were reviewed. Inclusion criteria included age (> 18), MDD diagnosed by standard tools (e.g., DSM-IV), use of cognitive and psychosocial assessments. Cross-sectional studies indicated that cognitive deficits in domains of executive functioning, attention, memory, and global cognition are associated with psychosocial dysfunction in domains of as quality of life, and social, occupational, and global functioning. The cognition-functioning relationship was also observed in longitudinal studies, showing that only specific cognitive domains affected psychosocial outcomes over the long-term course of illness. Older age and greater MDD symptom severity appear to enhance cognition-psychosocial dysfunction relationship, however little is known regarding the role of a number of other clinical factors (e.g., psychosis, illness duration).

Patients with chronic bipolar disorder exhibit widespread increases in extracellular free water

OBJECTIVES

Bipolar disorder (BP) is a debilitating psychiatric disease that is not well understood. Previous diffusion magnetic resonance imaging (dMRI) studies of BP patients found prominent microstructural white matter (WM) abnormalities of reduced fractional anisotropy (FA). Because FA is a nonspecific measure, relating these abnormalities to a specific pathology is difficult. Here, dMRI specificity was increased by free water (FW) imaging, which allows identification of changes in extracellular space (FW) from neuronal tissue (fractional anisotropy of tissue [FA-t]). Previous studies identified increased FW in early schizophrenia (SZ) stages which was replaced by widespread decreased FA-t in chronic stages. This is the first analysis utilizing this method to compare BP patients and controls.

METHODS

3 Tesla diffusion weighted imaging (3T DWI) data were acquired for 17 chronic BP and 28 healthy control (HC) participants at Oxford University. Tract-based spatial statistics was utilized to generate a WM skeleton. FW imaging deconstructed the diffusion signal into extracellular FW and tissue FA-t maps. These maps were projected onto the skeleton and FA, FA-t, and FW were compared between groups.

RESULTS

We found significantly lower FA in BP patients when compared to HC in areas that overlapped with extensive FW increases. There were no FA-t differences.

CONCLUSIONS

Our study suggests that chronic BP shows similar WM changes to early SZ, suggesting that extracellular FW increases could be a transient indication of recent psychotic episodes. Since FW increase in SZ has been suggested to be related to neuroinflammation, we theorize that neuroinflammation might be a shared pathology between chronic BP and early SZ.

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.

Functional impairment among people with severe and enduring mental disorder in rural Ethiopia: a cross-sectional study

PURPOSE

Evidence regarding functional impairment in people with severe mental disorders (SMD) is sparse in low- and middle-income countries. The aim of this study was to identify factors associated with functional impairment in people with enduring SMD in a rural African setting.

METHODS

A cross-sectional study was conducted at the baseline of a health service intervention trial. A total of 324 participants were recruited from an existing community-ascertained cohort of people with SMD (n = 218), and attendees at the Butajira General Hospital psychiatric clinic (n = 106). Inclusion criteria defined people with SMD who had ongoing need for care: those who were on psychotropic medication, currently symptomatic or had a relapse in the preceding 2 years. The World Health Organization Disability Assessment schedule (WHODAS-2.0) and the Butajira Functioning Scale (BFS) were used to assess functional impairment. Multivariable negative binomial regression models were fitted to investigate the association between demographic, socio-economic and clinical characteristics, and functional impairment.

RESULTS

Increasing age, being unmarried, rural residence, poorer socio-economic status, symptom severity, continuous course of illness, medication side effects, and internalized stigma were associated with functional impairment across self-reported and caregiver responses for both the WHODAS and the BFS. Diagnosis per se was not associated consistently with functional impairment.

CONCLUSION

To optimize functioning in people with chronic SMD in this setting, services need to target residual symptoms, poverty, medication side effects, and internalized stigma. Testing the impact of community interventions to promote recovery will be useful. Advocacy for more tolerable treatment options is warranted.

Predicting Mood Disturbance Severity with Mobile Phone Keystroke Metadata: A BiAffect Digital Phenotyping Study

Background

Mood disorders are common and associated with significant morbidity and mortality. Better tools are needed for their diagnosis and treatment. Deeper phenotypic understanding of these disorders is integral to the development of such tools. This study is the first effort to use passively collected mobile phone keyboard activity to build deep digital phenotypes of depression and mania.

Objective

The objective of our study was to investigate the relationship between mobile phone keyboard activity and mood disturbance in subjects with bipolar disorders and to demonstrate the feasibility of using passively collected mobile phone keyboard metadata features to predict manic and depressive signs and symptoms as measured via clinician-administered rating scales.

Methods

Using a within-subject design of 8 weeks, subjects were provided a mobile phone loaded with a customized keyboard that passively collected keystroke metadata. Subjects were administered the Hamilton Depression Rating Scale (HDRS) and Young Mania Rating Scale (YMRS) weekly. Linear mixed-effects models were created to predict HDRS and YMRS scores. The total number of keystrokes was 626,641, with a weekly average of 9791 (7861), and that of accelerometer readings was 6,660,890, with a weekly average 104,076 (68,912).

Results

A statistically significant mixed-effects regression model for the prediction of HDRS-17 item scores was created: conditional R²=.63, P=.01. A mixed-effects regression model for YMRS scores showed the variance accounted for by random effect was zero, and so an ordinary least squares linear regression model was created: R²=.34, P=.001. Multiple significant variables were demonstrated for each measure.

Conclusions

Mood states in bipolar disorder appear to correlate with specific changes in mobile phone usage. The creation of these models provides evidence for the feasibility of using passively collected keyboard metadata to detect and monitor mood disturbances.

Association of intracortical myelin and cognitive function in bipolar I disorder

OBJECTIVE

Although cognitive dysfunction persists through affective and euthymic states in bipolar disorder (BD), its neurobiological correlates remain undetermined. We explore whole-cortex intracortical myelin (ICM) and cognition in BD-I and controls.

METHODS

T₁ -weighted images (3T) optimized for ICM measurement were analyzed using a surface-based approach. MRI signal was sampled at cortical mid-depth. Cognitive performance was measured via standardized computerized battery and paper-and-pencil Trails B.

RESULTS

ICM was associated with verbal memory (VM) in BD throughout a cortical network identified with pertinence to VM function, with strongest effects in left caudal middle temporal cortex and left dorsolateral prefrontal cortex (P_corrected  < 0.05). Subanalyses revealed specific association with correct word recognition, without delay. Processing speed, executive function, and reaction time were also predicted by ICM in BD, but not controls, although this did not survive Bonferroni correction.

CONCLUSION

This is the first study to show VM association with ICM in BD. ICM has been implicated in the integrity of neural connections and neural synchrony. VM dysfunction is one of the most replicated cognitive abnormalities in BD. Therefore, these results provide a novel mechanism for understanding cognitive dysfunction in BD, which can aid in the development of targeted therapeutics to improve cognitive outcomes in BD.

Distinct patterns of blood oxygenation in the prefrontal cortex in clinical phenotypes of schizophrenia and bipolar disorder

BACKGROUND

Schizophrenia (SZ) and bipolar disorder (BD) are characterized by different clinical symptoms, and have previously been considered as categorically separate. However, several lines of evidence controversially suggest that these two disorders may run on a continuum. While it is therefore important to evaluate the subtle differences between SZ and BD, few studies have investigated the difference of brain functioning between the two by focusing on the common symptoms of cognitive functioning and impulsivity, rather than positive/negative and mood symptoms. Recent developments in near-infrared spectroscopy (NIRS) technology have enabled noninvasive assessment of brain function in people with psychiatric disorders.

METHODS

Near-infrared spectroscopy (NIRS) using 24-channels was conducted during the verbal fluency task (VFT) and Stroop color-word task (SCWT) in 38 patients diagnosed with SZ, 34 patients with BD, and 26 age- and sex-matched healthy controls.

RESULTS

Oxyhemoglobin changes in the prefrontal cortex (PFC) were significantly lower particularly in the SZ compared to control group during the VFT. On the other hand, these were significantly lower particularly in the BD and SZ group to control group during the SCWT. Regression analysis showed that hemodynamic changes were significantly correlated with verbal memory and impulsivity in both disorders.

CONCLUSION

These findings suggest that different hemodynamic responses in the prefrontal cortex might reflect cognitive functioning and impulsivity, providing a greater insight into SZ and BD pathophysiology.

Potential Gender-Related Aging Processes Occur Earlier and Faster in the Vermis of Patients with Bipolar Disorder: An MRI Study

BACKGROUND

In the last decades, there has been increasing interest in investigating the role of the vermis in bipolar disorder (BD), especially because of its involvement in cognitive processes. The main aims of this study were to explore the integrity of the vermis and elucidate the role of demographic and clinical variables on vermis volumes in BD patients, stratified according to gender.

METHODS

T1-weighted images were obtained for 38 BD patients and 38 healthy controls using a 1.5-T MRI scanner. Images were analyzed with a PC workstation with BRAINS2 software on a Linux system. Anatomical regions were traced manually from a blinded operator, with respect to subject identity and other clinical variables.

RESULTS

The direct comparison between the 2 groups showed no significant gray matter differences in vermis volumes. Interestingly, vermis volumes were significantly inversely associated with chronological age and age of BD onset, particularly in male subjects.

CONCLUSIONS

Our study provides evidence of the impact of aging on the vermis in BD, potentially related to earlier and faster gender-related neurodegenerative phenomena occurring during the progression of the disease.

Aripiprazole once-monthly as maintenance treatment for bipolar I disorder: a 52-week, multicenter, open-label study

Background

The long-acting injectable antipsychotic aripiprazole once-monthly 400 mg (AOM 400) was recently approved for maintenance treatment of bipolar I disorder (BP-I). The purpose of this study was to evaluate the safety, tolerability, and efficacy of AOM 400 as long-term maintenance treatment for BP-I.

Methods

This open-label multicenter study evaluated the effectiveness of AOM 400 as maintenance treatment for BP-I by assessing safety and tolerability (primary objective) and efficacy (secondary objective). The study enrolled AOM 400-naive (“de novo”) patients as well as AOM 400-experienced (“rollover”) patients with BP-I from a lead-in randomized, placebo-controlled clinical trial that demonstrated the efficacy of AOM 400 in the maintenance treatment of BP-I (Calabrese et al. in J Clin Psychiatry 78:324–331, 2017). Safety variables included frequency and severity of treatment-emergent adverse events (TEAEs) and TEAEs resulting in study discontinuation. Efficacy was assessed by the proportion of patients maintaining stability throughout the maintenance phase, as well as mean changes from baseline in Young Mania Rating Scale (YMRS), Montgomery–Asberg Depression Rating Scale, and Clinical Global Impressions for Bipolar Disorder–Severity of Illness Scale (CGI-BP-S) total scores. Patient acceptability and tolerability of treatment was assessed using the Patient Satisfaction with Medication Questionnaire-Modified.

Results

Of 464 patients entering the maintenance phase, 379 (82%) were de novo and 85 (18%) were rollover. TEAEs were more common in de novo than rollover patients. The overall discontinuation rate due to TEAEs was 10.3% (48/464). Improvements in YMRS and CGI-BP-S total scores were maintained during the study, and the vast majority of both de novo (87.0%) and rollover (97.6%) patients maintained stability through their last visit. Overall, the need for rescue medication during the maintenance phase was minimal (< 10% of patients). Patient satisfaction levels were high, with both de novo and rollover patients rating the side effect burden of AOM 400 as greatly improved relative to previous medications.

Conclusion

AOM 400 was safe, effective, and well tolerated by both de novo and AOM 400-experienced patients with BP-I for long-term maintenance treatment.

Trial registration ClinicalTrials.gov, NCT01710709

Electronic supplementary material

The online version of this article (10.1186/s40345-018-0122-z) contains supplementary material, which is available to authorized users.

Neuropsychological Functioning in Euthymic Phase of Bipolar Affective Disorder

BACKGROUND

A substantial proportion of euthymic bipolar disorder patients have neuropsychological impairment which can have a significant impact on the overall functional recovery.

MATERIALS AND METHODS

A total of 60 bipolar disorder patients, currently in euthymic phase for the last 3 months with minimum duration of illness 2 years and current Young Mania Rating Scale <7 and Hamilton Depression Rating Scale <6, currently on medications were administrated various neuropsychological tests.

RESULTS

Approximately half of the patients have neuropsychological impairments in the areas of mental speed, sustained attention, verbal fluency, working memory, set shifting, verbal and visual memory, and visual-constructional ability.

CONCLUSION

Findings of the current study provides evidence of neuropsychological impairment in euthymic bipolar disorder patients, and type of medications also has an impact on neuropsychological functions.

Assessment of cognitive functions in bipolar I disorder: A 1-year naturalistic follow-up study

OBJECTIVE

Available findings from cross-sectional studies have demonstrated cognitive impairments in bipolar I disorder (BD-I) during various phases of illness. However, very little is known about the longitudinal course of these cognitive impairments. The purpose of the study was to explore the longitudinal pattern of changes in cognitive functioning of BD-I patients.

METHODS

A total of 129 BD-I subjects (manic, depressed and euthymic groups) and 49 healthy controls were recruited using predefined selection criteria. All four study groups were assessed on various clinical and cognitive parameters (for attention, memory, executive functions and working memory) at study intake and at 3-monthly intervals over the next year.

RESULTS

All three patient groups performed poorly compared to controls on all cognitive measures at study intake and on some cognitive measures at the 3-, 6-, 9- and 12-month assessments. No significant time effects were observed for any cognitive test. A significant group by time interaction effect was found for executive functions (β = -44.74; P = .018) and working memory (β = 0.77; P ≤ .019) in the depressed group at 12 months; for visual memory (β = 1.21; P = .039) and working memory (β = 1.17; P ≤ .029) in the manic group at 12 months; and for working memory (β = -0.52; P ≤ .036) in the euthymic group at 12 months.

CONCLUSION

The patient groups showed significant impairments in all or some test domains relative to controls at all time-points. The cognitive functions largely remained stable in all patient groups, with slight improvement over time in a few tests. Further investigation is warranted in larger samples in longitudinal studies.

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

BACKGROUND

More than 50% of individuals with bipolar disorder (BD) do not reach full psychosocial functioning, even during periods of euthymia. It has been suggested that history of psychotic symptoms is one of the factors which are associated with a worse functional outcome. The objective was to compare psychosocial functioning between patients with BD, with (BD-P), and without (BD-NP) a history of psychotic symptoms, and to examine whether the history of psychotic symptoms, or other clinical or neurocognitive variables predict psychosocial functioning.

METHODS

Psychosocial functioning and neurocognition were examined in 100 euthymic patients with bipolar I disorder (50 BD-P, and 50 BD-NP), compared to 50 stabilised patients with schizophrenia (SZ), and 51 healthy controls (HC).

RESULTS

1) There were no differences between BD-P and BD-NP in the GAF-F score or in the FAST total score. 2) The two groups of patients with BD had better scores than SZ both in the GAF-F, and in all measures of the FAST, except for the subscale leisure time. 3) The neurocognitive composite index, verbal memory and subclinical depressive symptoms were the variables which explained a higher percentage of the variance of functional outcome.

LIMITATIONS

The cross-sectional design, and the relatively small sample size are the main limitations.

CONCLUSIONS

A history of psychotic symptoms has no relevant impact on the level of psychosocial functioning in BD. Neurocognitive dysfunction and subclinical depressive symptoms are the variables that best explain the functional impairment. These findings have important clinical implications.

Gender differences in C-reactive protein and homocysteine modulation of cognitive performance and real-world functioning in bipolar disorder

BACKGROUND

Cognitive and psychosocial impairment has been associated with increased levels of C-reactive protein (CRP) and homocysteine in bipolar disorder, but gender differences have seldom been studied.

METHODS

Two hundred and twenty-four bipolar outpatients were included. Cognitive performance was assessed through the Screen for Cognitive Impairment in Psychiatry (SCIP). Psychosocial functioning was evaluated using the Functioning Assessment Short Test (FAST) and the General Assessment of Functioning (GAF). Homocysteine and CRP levels were determined. Separate analyses were performed by gender. Partial correlations were calculated to test for associations between biomarkers and cognitive and psychosocial functioning. Hierarchical multiple regression was used to assess factors predicting cognitive and psychosocial functioning. Covariates were: age, education, duration of illness, hospital admissions, depressive symptoms, tobacco consumption, and BMI.

RESULTS

A better performance was noted in women in delayed verbal learning (p = 0.010), along with better occupational functioning (p = 0.027) and greater leisure time impairment (p = 0.034). In men, CRP and homocysteine levels were associated with psychosocial dysfunction (interpersonal relationships and financial functioning, respectively). In women, CRP levels correlated with cognitive performance (SCIP total raw score, immediate and delayed verbal learning, and verbal fluency). CRP was a predictor of cognitive performance in women only.

LIMITATIONS

The choice of the cognitive scale and covariates and the lack of a control group may be the main limitations.

CONCLUSIONS

A gender difference was found in biomarker modulation of cognition and psychosocial functioning. A gender-based approach to cognition and real-world functioning should be considered in bipolar disorder to ensure an optimal outcome.

Allostatic load but not medical burden predicts memory performance in late-life bipolar disorder

OBJECTIVE

Older patients with bipolar disorder (BD) present with variable degrees of cognitive impairment. Over time, stress, mood episodes, and comorbidities increase the body's allostatic load. We assessed the extent to which allostatic load vs more traditional measures of medical burden account for the heterogeneity in cognition in this population.

METHODS

Thirty-five older euthymic patients with BD and 30 age-equated, gender-equated, and education-equated comparison participants were administered a comprehensive assessment including a neuropsychological battery, and 9 physiological measures to determine allostatic load. The relationship among allostatic load, medical burden, and cognition was assessed.

RESULTS

Compared with the mentally healthy comparators, patients were impaired globally, and in 4 cognitive domains-information-processing speed / executive functioning, delayed memory, language, and visuomotor ability, and presented with greater medical burden but not a different allostatic load. Allostatic load, but not medical burden, was associated with delayed memory performance both in a correlational analysis and in a multivariate regression analysis.

CONCLUSION

Euthymic older patients with BD are impaired on several cognitive domains and have high medical burden. Their memory performance is more strongly associated with allostatic load than with traditional measures of medical burden. These findings need to be replicated and extended longitudinally.

The aldehyde dehydrogenase 2 polymorphisms on neuropsychological performance in bipolar II disorder with or without comorbid anxiety disorder

Anxiety disorders (ADs), the most common comorbid illnesses with bipolar disorder (BP) has been reported to associate with dopamine system. Dopamine, metabolized to 3,4-dihydroxyphenylacetic acid (DOPAC) by aldehyde dehydrogenase 2 (ALDH2), and the distribution of the ALDH2*1/*1, and ALDH2*1/*2+ALDH*2/*2 alleles in the Han Chinese general population is relatively equal. The association between dopamine metabolic enzymes and cognitive performance in patients with bipolar II disorder (BP-II) comorbid with AD is unclear. This study proposed to explore the role of ALDH2 polymorphisms on neuropsychological performance between BP-II comorbid with or without AD. One hundred ninety-seven BP-II patients with and without a comorbid AD were recruited and compared with 130 healthy controls (HCs). A polymerase chain reaction and a restriction fragment length polymorphism analysis were used to determine genotypes for ALDH2, and study participants underwent neuropsychological tests. An interaction between AD comorbidity and the ALDH2 polymorphisms was found in different domain of cognitive dysfunction in the BP-II patients. The ALDH2 polymorphisms might have different effects on the neuropsychological performance of BP-II patients with and without comorbid AD.

Cognitive functioning in first episode bipolar I disorder patients with and without history of psychosis

BACKGROUND

Psychosis in bipolar I disorder (BDI) has been associated with increased cognitive dysfunction, which may relate to poorer functional outcomes. However, it is not known whether cognition differs between BDI patients with (BDP+) or without (BDP-) history of psychosis early in the disease course, or if it is impacted by the presence of mood congruent (MCP) versus incongruent (MIC) psychotic features. We compare cognition between these groups in BDI patients recently recovered from first episode of mania.

METHODS

Attention, verbal learning/memory, processing speed and executive functioning were compared between: 1) all BDI patients (n = 73) and healthy controls (HC, n = 45), 2) BDP+ (n = 60) and BDP- (n = 13) patients and 3) MCP (n = 27) and MIC (n = 33) patients. Post-hoc analyses compared all patient groups with HC.

RESULTS

While BDI patients performed worse than HC in all domains, there were no significant differences between BDP+ and BDP-, or MCP and MIC, patients. However, BDP+ and MIC groups demonstrated different patterns of impairment compared to HC then did BDP- or MCP. Executive functioning and cognitive flexibility in particular appeared to be a deficit area in BDP+ patients.

LIMITATIONS

This study may have been underpowered to detect differences in direct comparison between BDP+ and BDP- patients.

CONCLUSION

While replication in larger samples is required, these results suggest that subtle cognitive differences between BDP+ and BDP-, and between MIC and MCP, patients may be present shortly after disease onset. These patient subsets may therefore be of interest in examining early intensive strategies to preserve cognition.

Dopamine D3 receptor blockade rescues hyper-dopamine activity-induced deficit in novel object recognition memory

Patients afflicted with bipolar disorder demonstrate significant impairments in recognition and episodic memory during acute depressive and manic episodes. These impairments and the related pathophysiology may result from over-activation of the brain dopamine (DA) system. In order to model overactive DA transmission in a well-established novel object recognition (NOR) memory test, we used DA transporter knockdown (DAT-KD) mice, which exhibit reduced DAT expression and display hyper-dopaminergic phenotypes. DAT-KD mice exhibited impaired NOR memory compared to wild-type (WT) mice. This impairment was prevented by administration of FAUC365, a DA D₃ receptor (D₃R) selective antagonist, prior to object learning. Similarly, D₃R knockout (KO)/DAT-KD double mutant mice displayed performance in the NOR test that was comparable to WT mice, suggesting that deficiencies in NOR performance in DAT-KD mice can be compensated by diminishing D₃R signaling. GBR12909, a DAT blocker, also impaired NOR performance in WT mice, but not in D₃R KO mice. Impaired NOR performance in GBR12909-treated WT mice was also prevented by pretreatment with FAUC365. Together, these findings indicate that reduced DAT activity can impair recognition memory in the NOR test, and D₃R appears to be necessary to mediate this effect.

Cognitive Impairment In Treatment-Naïve Bipolar II and Unipolar Depression

Cognition dysfunction may reflect trait characteristics of bipolarity but cognitive effects of medications have confounded previous comparisons of cognitive function between bipolar II and unipolar depression, which are distinct clinical disorders with some overlaps. Therefore, we examined the executive function (WCST), attention, cognitive speed (TMT-A) and memory (CAVLT, WMS-Visual reproduction) of 20 treatment-naïve bipolar II patients (BPII), 35 treatment-naïve unipolar depressed (UD) patients, and 35 age/sex/education matched healthy controls. The subjects were young (aged 18–35), and had no history of psychosis or substance use, currently depressed and meeting either RDC criteria for Bipolar II Disorder or DSM-IV-TR criteria for Major Depressive Disorder. The patients were moderately depressed (MADRS) and anxious(HAM-A), on average within 3.44 years of illness onset. Sociodemographic data and IQ were similar between the groups. UD patients had significantly slower cognitive speed and cognitive flexibility (WCST perseverative error). BPII depressed patients showed relatively intact cognitive function. Verbal memory (CAVLT List A total) correlated with illness chronicity only in BPII depression, but not UD. In conclusion, young and treatment-naïve BPII depressed patients differed from unipolar depression by a relatively intact cognitive profile and a chronicity-cognitive correlation that suggested a stronger resemblance to Bipolar I Disorder than Unipolar Depression.

Prospective memory in bipolar disorder: A meta-analysis

There are conflicting findings about prospective memory (PM) performance in bipolar disorder. This meta-analysis systematically examined PM in patients with bipolar disorders. Articles were systematically searched in both English and Chinese databases, from their inception to Nov 15, 2016. Only case-control studies on PM in bipolar patients were included for analyses. The random effect model was used in all meta-analytic outcomes. Four studies (n = 390) comparing PM performance between patients with bipolar disorder (n = 208) and healthy controls (n = 182) were included. Three studies were rated as "high quality", while the quality of evidence in 3 meta-analyzable outcomes ranged from "moderate" (67%) to "high" (33%). Compared to healthy controls, bipolar disorder patients showed impairments in overall PM [2 studies, n = 196; SMD: - 1.08 (95%CI: - 1.61, - 0.55), P < 0.0001; I² = 65%], event-based PM [4 studies, n = 367; SMD: - 0.51 (95%CI: - 0.78, - 0.23), P = 0.0003; I² = 37%] and time-based PM performance [4 studies, n = 367; SMD: - 0.82 (95%CI: - 1.11, - 0.52), P < 0.0001; I² = 41%]. In this meta-analysis, both time-based PM and event-based PM deficits appeared to be evident in bipolar disorder.

Biochemical abnormalities in basal ganglia and executive dysfunction in acute- and euthymic-episode patients with bipolar disorder: A proton magnetic resonance spectroscopy study

BACKGROUND

Recent studies found abnormal biochemical metabolism and executive cognitive deficits in acute bipolar disorder (BD). However, the evidence concerning in euthymic BD is limited. Thus, a comparison between acute and euthymic BD is conductive to better understanding the association between cognition and the outcome of neuroimaging. This study sought to investigate the relationship between the executive function and the biochemical metabolism in acute- and euthymic-episode BD patients and delineate the prominent endophenotype of BD.

METHODS

Three groups of participants were recruited in this study: 30 BD patients with an acute depressive episode, 22 euthymic BD patients, and 31 healthy controls. All participants were interviewed using the Structured Clinical Interview for DSM-IV, and underwent two-dimensional multivoxel proton magnetic resonance spectroscopy (1H-MRS) to obtain the bilateral metabolite levels in the lenticular nucleus of basal ganglia(BG). The ratios of N-acetylaspartate (NAA)/creatine (Cr) and Choline-containing compounds (Cho) /Cr ratios were calculated. Executive function was assessed by using the Wisconsin Card Sorting Test (WCST) and Trail Making Test, Part-B(TMT-B).

RESULTS

The comparison of biochemical changes showed that the NAA/Cr ratios in bilateral lenticular nucleus in both acute and euthymic BD patients was significantly lower than that in healthy controls at a confidence level of p<0.05. In the comparison of executive function, both acute and euthymic BD patients showed significantly decreased numbers of categories completed, and increased numbers of total errors, perseverative and noperseverative errors, and TMT-B uptake compared to the healthy controls at a confidence level of p<0.05. There were no significant differences between the acute BD and euthymic BD groups in the biochemical metabolite ratios and executive function. We found that the NAA/Cr ratio in the left in BG in the acute -episode BD patients was positively correlated with the number of categories completed, whereas it was negatively correlated with the total errors and TMT-B uptake. There was no correlation between the NAA/Cr and Cho/Cr ratios in the bilateral BG and the scores of SWCT and TMT-B in euthymic-episode BD patients.

LIMITATION

The sample size was relatively small and not all the euthymic-episode patients are the ones with an acute episode.

CONCLUSIONS

Our findings suggest that biochemical abnormalities in the lenticular nucleus and the executive dysfunction may occur early in the course of BD, and persist during remission, and are the most likely markers of endophenotypes of BD. The dysfunction of the neuronal function in the lenticular nucleus may be correlated with the cold dysfunction in patients with acute BD.