Mental health symptoms during imprisonment: a longitudinal study.

OBJECTIVE: Mental health problems are common in prison populations. Less is known about how mental health problems develop during imprisonment. The objective was to examine the longitudinal course of mental health symptoms during imprisonment and individual factors associated with the development of these symptoms.

METHOD: In a prospective cohort study, 1.664 Dutch male prisoners were questioned 3 weeks after their arrival in detention. Those still in custody were questioned again after 3, 9, and 18 months. Multilevel analyses were conducted to identify predictors of the course of mental health symptoms.

RESULTS: Prisoners reported continued elevated symptom levels compared to the general population. Inmates who entered detention with pre-existing mental health problems and problematic alcohol/drugs use showed mental health improvements during detention.

CONCLUSION: The high levels of prisoners' mental health problems highlight the importance of addressing mental health issues in prison. Imprisonment does not have an overall negative effect on mental health.