Comorbidity and multimorbidity in patients with schizophrenia and bipolar disorder: similarities and differencies.

BACKGROUND There is a need for better understanding and research of the comorbidity structure in schizophrenia and bipolar disorder. OBJECTIVE To assess the prevalence of somatic and psychiatric comorbidity in schizophrenia and bipolar affective disorder treated at the University Hospital Centre Zagreb. METHOD This retrospective study compares the prevalence of comorbid diagnosis of somatic and psychiatric disorders in 192 patients with schizophrenia and 97 patients with bipolar disorder. The diagnoses were established according to ICD-10 criteria. The data were collected from hospital medical documentation. RESULTS Patients with bipolar disorder had more both somatic (67.1% vs. 50.6%) and psychiatric (29.9% vs. 10.9%) comorbidity than patients with schizophrenia. The three most prevalent somatic comorbidites in patients with bipolar disorders were cardiovascular (22.6%), endocrinological (22.6%), and gastrointestinal (16.4%) disorders while neurological (11.4%), gastrointestinal (10.9%) and endocrinological (9.3%) disorders were the most frequent in patients with schizophrenia. CONCLUSION The exact prevalence and nature of the somatic and psychiatric comorbidity in patients with schizophrenia and bipolar disorder is still unclear and further research is needed.