The Bipolar Comprehensive Outcomes Study (BCOS): baseline findings of an Australian cohort study

The Bipolar Comprehensive Outcomes Study (BCOS) is a 2-year, observational study of participants with bipolar I or schizoaffective disorder examining clinical, functional, and economic outcomes associated with naturalistic treatment.

Participants prescribed mood stabilisers were assessed using various measures, including the Young Mania Rating Scale (YMRS), 21-item Hamilton Depression Rating scale (HAMD21), Clinical Global Impressions-Bipolar Version Severity of Illness scale (CGI-BP), and the EuroQol instrument (EQ-5D).

240 participants were recruited from two sites. On average, participants were 41.8+/-12.7 years of age (mean+/-SD), 58.3% were female, and 73.3% had a diagnosis of bipolar I disorder at study entry. The majority of participants were moderately ill, with an average CGI-BP Overall score of 3.8+/-1.3. Most participants had subthreshold mania and depression symptoms, indicated by HAMD21 Total 13.4+/-8.6, CGI-BP Depression 3.2+/-1.3, YMRS Total 8.2+/-8.5 and CGI-BP Mania 3.0+/-1.6 average scores. For bipolar participants, 94.6% of hospitalisations for psychiatric treatment in the past 3 months were single admissions (vs. 65.2% for schizoaffective participants, p=.002). Bipolar participants rated their overall health state higher (EQ-5D scores: 68.2+/-18.8 vs. 61.6+/-22.7, p=.023), had a higher mean weekly wage ($500-$999, 21.3% vs. 6.3%), lower unemployment (22.2% vs. 48.4%), and higher romantic relationship status (47.1% vs. 26.6%).

The observational design and small sample size may have limited the causal relationships and generalisability within the current findings.

Participants were characterised by social and occupational dysfunction at entry, but schizoaffective participants appeared to be more severely affected. Effective treatment is required to address both clinical and functional impairment.