Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.

The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.

There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.

These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

The term “subjective response to antipsychotic” (SRA) refers to changes in the subjective state experienced due to antipsychotic (AP) exposition that is independent of the therapeutic or physical side effects of these drugs. This dimension of analysis has been extensively explored in schizophrenic disorders, finding that negative SRA is an early and independent predictor of compliance as well as a successful pathway to construct current theoretical frameworks of these disorders. There is an increasing use of AP in bipolar disorders’ treatment (BD) but no reviews on the topic have been published to date in this population. The aim of this work is to review published data of SRA in BD patients and to discuss their clinical and theoretical implications.

An extensive search in online databases was performed. Reports were reviewed and included if they described SRA in BD or included instruments aimed to assess it. Reports of cognitive, sexual, motor autonomic side effects were excluded. Findings were summarized in a narrative fashion.

Nine reports fulfilled the inclusion criteria and were included in the revision, reporting data from 1282 BD patients. Among these, three were prospective studies and three explored relations between SRA and treatment compliance.

There is an asymmetry between the increase in the use of antipsychotics in BD and the lack of data regarding the SRA. Phenomenologically, SRA in BD is similar to that found in schizophrenic subjects. Some of these symptoms may be misdiagnosed as depressive symptoms. The existing data show that SRA has a strong correlation with treatment compliance as well as a promising way to develop theoretical paradigms for these disorders.

The main aim of this study was to compare a large population of patients with bipolar disorder (BD) types I and II strictly defined as euthymic with healthy controls on measures of decision making. An additional aim was to compare performance on a decision-making task between patients with and without a history of suicide attempt.

Eighty-five euthymic patients with BD-I or BD-II and 34 healthy controls were included. All subjects completed tests to assess verbal memory, attention and executive functions, and a decision-making paradigm (the Iowa Gambling Task, IGT).

Both groups of patients had worse performance than healthy controls on measures of verbal memory, attention and executive function. No significant differences were found between BD-I, BD-II and healthy controls on measures of decision making. By contrast, patients with a history of suicide attempt had lower performance in the IGT than patients without a history of suicide attempt.

Patients with euthymic BD-I and BD-II had intact decision-making abilities, suggesting that this does not represent a reliable trait marker of the disorder. In addition, our results provide further evidence of an association between impairments in decision making and vulnerability to suicidal behavior.