Suicide in prison in the North of Italy (1993-2022): a case-control study examining differences between suicides inside and outside prison

Prisoners constitute a group at suicide risk, showing higher relative rates of suicides than the general population. However, there is limited knowledge about the characteristics of those who die by suicide in Italian prisons. Based on the total sample of suicides of the Institute of Forensic Medicine of Milan (1993-2022), suicides in prison (N = 120) were matched by age and gender with cases that occurred outside prison (N = 300) and compared with them. The considered variables were sociodemographic, clinical, and suicide-related. Univariate analyses and logistic regression model were performed. In univariate analyses, suicides in prison showed higher rates of ethnicity different from white Caucasian, lower rates of depression, higher rates of alcoholism, addiction, respiratory system diseases, hepatitis, and amyotrophic lateral sclerosis, lower use of any medication, and in particular psychotropic medications, and a higher percentage of violent suicide method versus nonviolent compared to suicides outside prison. In the logistic regression model, ethnicity, depression, and addiction were the only features differentiating suicides in prison from ones outside prison. Particular attention should be paid to inmates with non-white ethnicity and those with addiction. Ensuring adequate access to psychiatric care and implementing comprehensive suicide prevention strategies within Italian prisons is crucial.