Mental illness as a factor in criminality: A study of prisoners and mental patients

Abstract

Data were collected on two samples of patients admitted to New York State Psychiatric centres and two samples of inmates admitted to New York State prisons to assess the relationship between mental disorder and arrest. Differences in criminality were looked for among four groups: prisoners with no state mental hospitalisations before admission; prisoners with previous mental hospitalisations, patients with previous arrests, and patients with no previous arrests. Both types of patients were at lower risk of arrest than prisoners and there was a fairly consistent ordering in the rates and probabilities of subsequent criminality (prisoners with no previous hospitalisation history > prisoners with previous mental hospitalisations > patients with previous arrests > patients with no prior arrests) . The ordering of arrest data could be due to pre‐existing differences among the groups, the nature of the treatment received, or some combination of the two.