Prospective observational cohort study of 'treatment as usual' over four years for patients with schizophrenia in a national forensic hospital.

Change in response to multi-modal psychosocial programs (DUNDRUM-3) reduced a measure of violence proneness over four years. Forensic in-patients' ability to benefit from psychosocial treatment appears to be a function of the outcome measure used, unit of measurement employed, degree of cognitive impairment, psychopathology, and length of stay. Lower risk of re-offending may be partially attributable to participation and engagement in psychosocial interventions.