Prevalence rates of mental disorders in Chilean prisons.

OBJECTIVE: High rates of mental disorders have been reported for prison populations worldwide, particularly in low- and middle-income countries (LMICs). The present study aimed to establish prevalence rates of mental disorders in Chilean prisoners. METHOD: A nationwide random sample of 1008 prisoners was assessed in 7 penal institutions throughout Chile. Twelve-month prevalence rates were established using the Composite International Diagnostic Interview (CIDI) and compared to the prevalence rates previously published for the general population. RESULTS: Prevalence rates were 12.2% (95% CI, 10.2-14.1) for any substance use disorder, 8.3% (6.6-10.0) for anxiety disorders, 8.1% (6.5-9.8) for affective disorders, 5.7% (4.4-7.1) for intermittent explosive disorders, 2.2% (1.4-3.2) for ADHD of the adult, and 0.8% (0.3-1.3) for non-affective psychoses. Significantly higher prevalence rates among prisoners as compared to the general population in Chile were seen for major depression (6.1% vs. 3.7% males, Z=2.58, p<0.05) and illicit drug use (3.3% vs. 0.6% males with drug abuse, Z=2.04, p<0.05; 2.6% vs. 0.1% females with drug abuse, Z=5.36, p<0.001; 3.4% vs. 1.1% males with drug dependence, Z=3.70; p<0.001). Dysthymia (6.5% vs. 15.6%, Z=-2.39, p<0.05), simple (3.3% vs. 11.5%, Z=-3.13, p<0.001) and social phobias (3.9% vs. 9.7%, Z=2.38, p<0.05) were significantly less frequent in the female prison population than in the general population. One-year prevalence rates of alcohol abuse (2.3% vs. 3.9%; Z=-2.04; p<0.05) and dependence (2.7% vs. 8.2%; Z=-5.24; p