Medical comorbidity in patients with schizophrenia and bipolar disorder is associated with poor psychiatric treatment outcome and,for inpatients, with increased length of stay (LOS) -either by increasing psychiatric symptomatology or by being the focus of medical attention.

To assess the impact of medical comorbidity that receives medical attention (as opposed to lack of concurrent medical problems or to stable comorbidity) on clinical outcomes and LOS within two psychiatric populations.

To estimate the prevalence of comorbid medical conditions in schizophrenia and bipolar disorder. To test for differences, primarily in LOS and psychiatric treatment outcome, between inpatients who received care for physical problems and those who did not need to.

This was a retrospective study of consecutive voluntary admissions of 106 patients suffering from schizophrenia and 110 patients suffering from bipolar disorder (type I or II). Our main independent variable was whether or not inpatients received treatment for a medical condition after referral from the attending psychiatrist. We used GAF and CIRS-SA assessments.

Most reported problems for schizophrenia patients were cardiovascular/respiratory (notably hypertension) and for bipolar patients endocrine/metabolic. Patients who received medical treatment did not differ in LOS or psychiatric outcome from those who did not receive, in either diagnosis group. 84% of bipolar patients who reported a psychiatric comorbidity received treatment for a medical problem.

Medical care for comorbid physical problems does not impact on LOS, diagnosis being a better predictor of the latter. In bipolar disorder significant medical burden appears to be drug-induced.