Prevalence of mental illness among Aboriginal and Torres Strait Islander people in Queensland prisons

Objective: To estimate the prevalence of mental disorder in a representative sample of Aboriginal and Torres Strait Islander people in Queensland prisons. Design, setting and participants: Cross-sectional assessment of mental health using the Composite International Diagnostic Interview (CIDI) and clinical interviews, conducted by Indigenous mental health clinicians who undertook specific training for this purpose, with support from forensic psychiatrists when indicated. We assessed adults who self-identified as Indigenous and were incarcerated in six of the nine major correctional centres across Queensland (housing 75% of all Indigenous men and 90% of all Indigenous women in Queensland prisons) between May and June 2008. Main outcome measures: Diagnoses of anxiety, depressive and substance misuse disorders using the CIDI; diagnosis of psychotic illness determined through psychiatrist interviews supplemented by a diagnostic panel. Results: We interviewed 25% of all Indigenous men (347/1381; mean age, 31.5 years) and 62% of all Indigenous women (72/116; mean age, 29.2 years) incarcerated at the time of our study. The recruitment fraction was 71% for men and 81% for women. Among the 396 individuals who completed both the interview and the CIDI, the 12-month prevalence of mental disorder was 73% among men and 86% among women. This comprised anxiety disorders (men, 20%; women, 51%); depressive disorders (men, 11%; women, 29%); psychotic disorders (men, 8%; women, 23%) and substance misuse disorders (men, 66%; women, 69%). Conclusions: The prevalence of mental disorder among Indigenous adults in Queensland custody is very high compared with community estimates. There remains an urgent need to develop and resource culturally capable mental health services for Indigenous Australians in custody