Lung function and respiratory diseases in people with psychosis: population-based study.

BACKGROUND There is little information on lung function and respiratory diseases in people with psychosis. AIMS To compare the respiratory health of people with psychosis with that of the general population. METHOD In a nationally representative sample of 8028 adult Finns, lung function was measured by spirometry. Information on respiratory diseases and symptoms was collected. Smoking was quantified with serum cotinine levels. Psychotic disorders were diagnosed utilising the Structured Clinical Interview for DSM-IV (SCID-I) and medical records. RESULTS Participants with schizophrenia and other non-affective psychoses had significantly lower lung function values compared with the general population, and the association remained significant for schizophrenia after adjustment for smoking and other potential confounders. Schizophrenia was associated with increased odds of pneumonia (odds ratio (OR) = 4.9), chronic obstructive pulmonary disease (COPD, OR = 4.2) and chronic bronchitis (OR = 3.8); and with high cotinine levels. CONCLUSIONS Schizophrenia is associated with impaired lung function and increased risk for pneumonia, COPD and chronic bronchitis.