BACKGROUND: Although it is well established that chronic somatic diseases are significantly associated with a wide range of psychopathology, it remains unclear to what extent subjects with chronic somatic diseases are at increased risk of experiencing mental disorders. The present epidemiological study investigates age- and sex-adjusted 12-month prevalence rates of mental disorders in patients with cancer, and musculoskeletal, cardiovascular and respiratory tract diseases, based on comprehensive physicians' diagnoses and compared with physically healthy probands.

METHODS: Prevalence rates were calculated from two large epidemiological surveys. These studies investigated inpatients and patients from the general population with cancer (n = 174) and musculoskeletal (n = 1,416), cardiovascular (n = 915) and respiratory tract diseases (n = 453) as well as healthy controls (n = 1,083). The prevalence rates were based on the Munich Composite International Diagnostic Interview, a standardized interview for the assessment of mental disorders.

RESULTS: Prevalence rates were very similar for inpatients (43.7%) and patients from the general population (42.2%). The adjusted odds ratios (OR) of patients with chronic somatic diseases were significantly elevated for mental disorders in comparison with healthy probands (OR: 2.2). Mood, anxiety and somatoform disorders were most frequent. The prevalence rates did not differ significantly between the somatic index diseases. The number of somatic diseases per patient had a higher association with mental disorders.

CONCLUSIONS: There is a strong relationship between chronic somatic diseases and mental disorders. A future task is to improve the care of mental disorders in patients with chronic physical illness, specifically with multimorbid conditions.