Mental Illness, Social Exclusion, and Crime: A Criminological Examination of Psychiatric Disorders and Offending Behaviour

This preprint is a systematic narrative review of the relationship between psychiatric illness, social exclusion and criminal justice involvement. It synthesises peer-reviewed literature from criminology, psychiatry, psychology, social policy and public health, largely published between 2000 and 2025. The article argues that psychiatric illness alone is a weak and unreliable predictor of offending. The overrepresentation of people with mental illness in criminal justice systems is better explained by interacting factors: trauma and adverse childhood experiences, substance misuse, homelessness, poverty, stigma, and gaps in community mental health care. The review also shows that different diagnoses carry very different risk profiles, so “mental illness” should not be treated as a single category. It applies five theoretical frameworks (General Strain Theory, Labelling Theory, Social Control Theory, Social Learning Theory and Critical Criminology) within an integrated multi-level model. It concludes by recommending policy responses that prioritise community mental health services, integrated dual diagnosis treatment, Housing First, trauma-informed care, anti-stigma initiatives and diversion programs over punitive responses. The article was written for criminology, forensic mental health and criminal justice policy audiences. It has not been peer reviewed.