Mental health in prison populations. A review - with special emphasis on a study of Danish prisoners on remand

Objective: To review the literature on mental health and psychiatric morbidity in prison populations and relate findings to a Danish study on remand prisoners. Method: The literature is reviewed and subdivided in the following section: validity of psychometrics in prison populations, prevalence of psychiatric disorders prior to imprisonment, incidence of psychiatric disorders during imprisonment, psychopathy related to psychiatric comorbidity, dependence syndromes with special emphasis on different administrations of heroin use (smoke vs. injection). The results are compared with a longitudinal Danish study on remand prisoners in either solitary confinement (SC) or non-SC. Results: Many factors must be taken into consideration when dealing with prisoners and mental health, e.g. international differences, the prison setting, demographics and methodological issues. The prison populations in general are increasing worldwide. Psychometrics may perform differently in prison populations compared with general populations with the General Health Questionnaire-28 having a low validity in remand prisoners. Psychiatric morbidity including schizophrenia is higher and perhaps increasing in prison populations compared with general populations with dependence syndromes being the most frequent disorders. The early phase of imprisonment is a vulnerable period with a moderately high incidence of adjustment disorders and twice the incidence in SC compared with non-SC. Prevalence of psychopathy is lower in European than North American prisons. Medium to high scores of psychopathy is related to higher psychiatric comorbidity. Opioid dependence is the most frequent drug disorder with subjects using injection representing a more dysfunctional group than subjects using smoke administration. Many mentally ill prisoners remain undetected and undertreated. Conclusion: There is a growing population of mentally ill prisoners being insufficiently detected and treated.