Common mental disorders and disability across cultures. Results from the WHO Collaborative Study on Psychological Problems in General Health Care.

OBJECTIVE To examine the impact of common mental illness on functional disability and the cross-cultural consistency of this relationship while controlling for physical illness. A secondary objective was to determine the level of disability associated with specific psychiatric disorders. DESIGN A cross-sectional sample selected by two-stage sampling. SETTING Primary health care facilities in 14 countries covering most major cultures and languages. PATIENTS A total of 25,916 consecutive attenders of these facilities were screened for psychopathology using the General Health Questionnaire (96% response). Screened patients were sampled from the General Health Questionnaire score strata for the second-stage Composite International Diagnostic Interview administered to 5447 patients (62% response). MAIN OUTCOME MEASURES Patient-reported physical disability, number of disability days, and interviewer-rated occupational role functioning. RESULTS After controlling for physical disease severity, psychopathology was consistently associated with increased disability. Physical disease severity was an independent, although weaker, contributor to disability. A dose-response relationship was found between severity of mental illness and disability. Disability was most prominent among patients with major depression, panic disorder, generalized anxiety, and neurasthenia; disorder-specific differences were modest after controlling for psychiatric comorbidity. Results were consistent across disability measures and across centers. CONCLUSIONS The consistent relationship of psychopathology and disability indicates the compelling personal and socioeconomic impact of common mental illnesses across cultures. This suggests the importance of impairments of higher-order human capacities (eg, emotion, motivation, and cognition) as determinants of functional disability.