Medical comorbidity in bipolar disorder: implications for functional outcomes and health service utilization

This is the first cross-national population-based investigation exploring the prevalence and functional implications of comorbid general medical disorders in bipolar disorder.

Data were extracted from the Canadian Community Health Survey (N = 36,984). Analyses were conducted to ascertain the prevalence and prognostic implications of predetermined comorbid general medical disorders among persons who screened positive for a lifetime manic episode (indicative of a diagnosis of bipolar disorder). Within the subpopulation of people who screened positive for a manic episode, the effect of medical comorbidity on employment, functional role, psychiatric care, and medication use was examined.

When the data were weighted to be representative of the household population of the ten provinces in 2002, an estimated 2.4 percent of respondents screened positive for a lifetime manic episode. Rates of chronic fatigue syndrome, migraine, asthma, chronic bronchitis, multiple chemical sensitivities, hypertension, and gastric ulcer were significantly higher in the bipolar disorder group (all p < .05). Chronic medical disorders were associated with a more severe course of bipolar disorder, increased household and work maladjustment, receipt of disability payments, reduced employment, and more frequent medical service utilization.

Comorbid medical disorders in bipolar disorder are associated with several indices of harmful dysfunction, decrements in functional outcomes, and increased utilization of medical services.