Background: The present study sought to determine the prevalence of substance abuse, mental illness, sociodemographics and clinical characteristics of mentally ill offenders. These data were compared to data from the prison population in the United Kingdom.
Method: This is a cross-sectional study of male, mentally ill offenders in two prisons in Jamaica, and four prisons in England and Wales. For the Jamaican sample, a psychopathology and forensic survey instrument was developed by the research personnel to extract specific information from the diagnostic interview. Data extraction was done over a one-year period. For the England and Wales sample, the participants were interviewed and assessed using various structured instruments.
Results: The results indicate that approximately 18% of persons within the Jamaican prison population under study had a mental illness. Of this number, 57% of these persons had been previously diagnosed with a Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM IV-TR) Axis 1 disorder. Substance abuse was the most frequently diagnosed DSM-IV Axis I disorder within both populations. The prevalence of mental illness found in the Jamaican prison population was approximately four times greater than the rate in the comparison population of England and Wales.
Conclusions: There was an over-representation of mentally ill offenders in the Jamaican prison population. This is most likely linked to the lack of appropriate diversion programmes and a forensic mental hospital in Jamaica.