High prevalence of mental disorders in primary care.

OBJECTIVE: To determine the prevalence of common mental disorders in an adult primary care population.

DESIGN: Cross-sectional survey in randomly selected subjects, using the PRIME-MD questionnaire.

SETTING: Eighty-six general practices in Belgium.

SUBJECTS: A total of 2316 randomly selected patients, aged 18 years or older and consulting their general practitioner for other than administrative reasons alone, with slightly more women (58.1%) than men (41.3%). MAIN OUTCOME RESULT: Prevalence rates of mental disorders most commonly seen in primary care practice (mood, anxiety, somatoform, eating and alcohol disorders).

METHODS: To facilitate data collection and processing, the entire PRIME-MD questionnaire was programmed on a handheld computer. Patient answers and physician assessments were immediately electronically recorded during the interview. All investigators were trained on the use of the PRIME-MD. The recruitment period lasted 6 weeks: from 15 February to 25 March 1999, and patients were randomly selected for the interview based on a computerized procedure.

RESULTS: Although only 5.4% of all patients consulted for a psychiatric reason, a threshold/subthreshold psychiatric disorder was detected in 42.5% of all patients. Most commonly detected disorders were mood disorders in 31.0% (major depressive disorder, 13.9% and dysthymia, 12.6%), anxiety disorders in 19.0% (generalized anxiety disorder, 10.3%), somatoform disorders in 18.0% and probable alcohol abuse/dependence in 10.1%. The results also showed the important rate of comorbidity between these disorders.

CONCLUSION: The present study confirms the high prevalence of mental disorders in a general practice setting, and their frequent association. Prevalence rates of our study are even higher than those obtained in previously conducted trials. Our study also demonstrates the utility of the PRIME-MD as a screening tool for mental disorders in primary care. In addition the use of the handheld computer software version of the PRIME-MD allowed us to screen for mental disorders in patients who are unable to attend the GP office and are seen during 'home' visits.