Chronic obstructive lung diseases and prevalence of mood, anxiety, and substance-use disorders in a large population sample.

Only a few population-based studies have examined prevalence of mental disorder in people with chronic respiratory conditions. Clinical studies have yielded mixed results. In this analysis, data from the 2002 Canadian Community Health Survey (CCHS) were used. This was a national health survey that included administration of the World Mental Health Composite International Diagnostic Interview to a sample of 36,984 subjects. Participants were asked about chronic medical conditions that had been diagnosed by a health professional. Chronic respiratory conditions were associated with major depressive disorder, bipolar disorder, panic disorder (including agoraphobia), social phobia, and substance dependence. Although the observed associations were statistically highly significant, the prevalence estimates were lower than previous reports from studies using clinical samples, suggesting that selection bias may have influenced some estimates.