SPECIFIC MAJOR MENTAL-DISORDERS AND CRIMINALITY - A 26-YEAR PROSPECTIVE-STUDY OF THE 1966 NORTHERN FINLAND BIRTH COHORT

Objective: The purpose of the study was to examine the quantitative ri sk of criminal behavior associated with specific mental disorders. Met hod: An unselected 1966 birth cohort (N=12,058) in Northern Finland wa s prospectively studied until the end of 1992. The investigation start ed during the mothers' pregnancy, and the data on the subjects' family characteristics, mental and physical development, living habits, psyc hiatric morbidity, and criminal records were gathered at various times . Results: The prevalence of offenses was the highest among males with alcohol-induced psychoses and male schizophrenic subjects with coexis ting alcohol abuse, and more than half of the schizophrenic offenders also had problems with alcohol. Eleven (7%) of the 165 subjects who co mmitted violent crimes were diagnosed as psychotic. Male schizophrenic subjects had a moderately high risk for violent offenses, but the ris k for other types of crimes was not elevated significantly. Odds ratio s for criminal behavior were adjusted according to the socioeconomic s tatus of the childhood family and were the same as or slightly lower t han the crude odds ratios for all disorders except schizophrenia and m ood disorders with psychotic features. Conclusions: The results indica te that the risk of criminal behavior was significant higher among sub jects with psychotic disorders, even though the socioeconomic status o f the childhood family was controlled. The higher risk for violent beh avior was associated especially with alcohol-induced psychoses and wit h schizophrenia with coexisting substance abuse. The results suggest t hat schizophrenia without substance abuse may also be associated with a higher risk of offenses, but this finding is tentative and requires further investigation.