Emotional processing subtypes in bipolar disorder: A cluster analysis.

BACKGROUND: Evidence regarding the performance of Bipolar Disorder patients (BD) on Emotional Processing (EP) is conflicting, suggesting that heterogeneity within this population may exist. It is not completely understood if this impacts on clinical presentation and functional outcomes. METHODS: A total of 212 BD patients were recruited. Patients underwent MATRICS Consensus Cognitive Battery as well as a clinical evaluation to detect premorbid traits, comorbidities and clinical features. Performance on each basic emotion on the Emotional Recognition Task (ERT) and Reading the Mind in the Eyes Test were entered into hierarchical cluster analyses in order to determine the number of clusters and to assign subjects to specific clusters. We then compared subgroups on clinical factors and real-world community functioning. RESULTS: No differences between BD patients as a group and controls were found in EP performance. Two clusters of BD patients were found, one with "intact" performance (71.2%) that performed as healthy controls (HC) and other with "impaired" performance (28.8%) performing worse than HC and schizophrenic patients on basic emotion recognition. Patients in the "impaired group" presented higher rates of childhood trauma, schizotypal traits, lower premorbid IQ and education, poor psychosocial functioning and cognitive performance. LIMITATIONS: Cross-sectional data which limits our ability to infer directionality of our findings. CONCLUSION: These results suggest the presence of two subgroups regarding EP performance with unique clinical and neurodevelopmental profiles associated. Next steps will include using these data to identify a homogeneous group of patients to target these disabling symptoms with treatment.

Characterization of Mood Instability through Bipolar Disorders: A cluster-analytic approach using weekly prospective life-chart methodology.

BackgroundThe aim of this study was to characterize mood instability (MI) in Bipolar Disorder (BD) and to investigate potential differences between subtype I and II. MethodsLife-charts from weekly mood ratings of 90 patients were used to compute: weeks spent with symptoms, number of episodes, and MI. Regression analyses were conducted to assess the relationship between BD subtype and MI adjusting by all potential confounding factors. Hierarchical cluster analysis was performed to determine the appropriate number of clusters that described the data and to assign subjects to a specific cluster based on their MI. We then compared clusters on clinical and psychosocial outcomes. ResultsMedian follow-up was 5 years (IQR: 3.6-7.9). Patients spent 15.2%, 5%, and 3% of follow-up with depressive, manic, and mixed symptoms, respectively. BD type II presented higher MI (ß = 1.83, 95% CI: 0.66-3.00) and subsydromal symptoms than BD type I patients. No differences in functioning or recurrences were found between subtypes. Differences in MI between the two clusters mimicked those between type I and II but enhanced (ß = 3.86, 95%CI -4.72, -2.66). High MI (n = 43) patients presented poorer functioning and higher recurrences compared to Low MI patients (n = 43). ConclusionBD type II presented higher MI and subsyndromal symptoms than BD type I patients. However, these differences did not translate into clinically relevant outcomes. A classification based on MI may provide useful clinical insights.

Dopaminergic agents in the treatment of bipolar depression: a systematic review and meta-analysis.

OBJECTIVE: To systematically examine the effects of dopaminergic agents (modafinil, armodafinil, pramipexole, methylphenidate, and amphetamines) on bipolar depression outcomes. METHODS: Meta-analysis of randomized controlled trials was performed to assess the efficacy and safety of treatment with dopaminergic agents in bipolar depression. In a secondary analysis, findings from both randomized controlled trials and high-quality observational studies were pooled by means of meta-analytic procedures to explore dopaminergic treatment-related new mania. RESULTS: Nine studies (1716 patients) were included in our meta-analysis of randomized controlled trials. Treatment with dopaminergic agents for bipolar depression was associated with an increase in both response (1671 individuals, RR 1.25, 95% CI 1.05 to 1.50) and remission rates (1671 individuals, RR 1.40, 95% CI 1.14, 1.71). There was no evidence of an increased risk of mood switch associated with this treatment (1646 individuals, RR 0.96, 95% CI 0.49, 1.89). Our secondary analysis (1231 individuals) yielded a cumulative incidence of mood switch of 3% (95% CI 1.0, 5.0) during a mean follow-up period of 7.5 months. CONCLUSIONS: Preliminary findings suggest that dopaminergic agents may represent a useful alternative for the treatment of bipolar depression, with no evidence for a related increase in the risk of mood destabilization during short-term follow-up.

Are major depression and bipolar disorder neuropsychologically distinct? A meta-analysis of comparative studies.

BACKGROUND: Neuropsychological deficits are present in both major depression and bipolar disorder. So far, however, reports directly comparing these mood disorders with regard to cognitive outcomes have been scant and yielded inconsistent results. This work aims to combine the findings of comparative studies of cognition in major depression and bipolar disorder in order to explore whether these neuropsychiatric conditions present with distinct cognitive features. METHODS: The main online databases were extensively searched to retrieve reports assessing neurocognitive functioning in two groups of mood disorder patients, one with major depressive disorder and another with bipolar disorder, both in the same phase of illness. Between-group effect sizes for cognitive variables were obtained from selected studies and pooled by means of meta-analytic procedures. RESULTS: During euthymia, a significant overall effect size (Hedges'g=0.64, P<0.001) favoring major depressive disorder was found for verbal memory as assessed with list learning tests, whereas no significant between-group differences were found for the remaining variables analyzed. During depressive episodes, similar cognitive outcomes were observed between groups. CONCLUSION: At present, it is not possible to postulate specific neuropsychological profiles for major depression and bipolar disorder in light of available evidence. It remains to be ascertained whether the differences found for verbal memory constitute an expression of distinct underlying mechanisms or whether they are best explained by sample characteristics or differential exposure to variables with a negative impact on cognition.