Mental-physical comorbidity in Te Rau Hinengaro: the New Zealand Mental Health Survey.

OBJECTIVE: To estimate the prevalence of chronic physical conditions, and the risk factors for those conditions, among those with 12 month mental disorder; to estimate the prevalence of 12 month mental disorder among those with chronic physical conditions.

METHOD: A nationally representative face-to-face household survey was carried out in October 2003 to December 2004 with 12,992 participants aged 16 years and over, achieving a response rate of 73.3%. Mental disorders were measured with the World Mental Health version of the Composite International Diagnostic Interview (CIDI 3.0). Physical conditions were self-reported. All associations are reported adjusted for age and sex.

RESULTS: People with (any) mental disorder, relative to those without mental disorder, had higher prevalences of several chronic physical conditions (chronic pain, cardiovascular disease, high blood pressure and respiratory conditions) and chronic condition risk factors (smoking, overweight/obesity, hazardous alcohol use). Around a quarter of people with chronic physical conditions had a comorbid mental disorder compared with 15% of the population without chronic conditions. Significant relationships occurred between some mental disorders and obesity, cardiovascular disease and diabetes for females, but not for males.

CONCLUSIONS: This paper provides evidence of substantial comorbidity between mental disorders and chronic physical conditions in New Zealand. This should be borne in mind by clinicians working in both mental health and medical services.