Evidence suggests that persons with psychiatric diagnosis born in late 1940s and 1950s are at higher risk for violent behavior than other psychiatric patients from two reasons: 1/ these generations received inappropriate mental health care associated with deinstitutionalization; 2/ their individual characteristics may have differed because of factors, which affected their prenatal and perinatal period. The fact that between 1949 and 1989 Czech socialist health care system ignored the deinstitutionalization policy provides the opportunity for us to test this theory.

During our previous work we collected data on prevalence of violence in four cohorts of schizophrenic in years: 1949,1969, 1989 and 2000. Using the chart records all 572 patients were re-diagnosed. Only those patients (N=404) meeting the DSM IV criteria for schizophrenia were included in the study. For the purposes of this study we divided all 404 patients to the three groups: Patients born before 1946 (N=249), patients born in late 1940s and 1950s - between 1946 and 1959 - (N=84), and patient born after 1959 (N=71).

We tested the association of categorical year of birth (< 1946, 1946-1959, > 1959) and found no association (unadjusted and adjusted for cohort, observation years and gender) of year of birth and violent behavior (Pearson chi2 = 0.2798, Pr = 0.869).

Our findings suggest that only organizational changes are responsible for increase risk of violence.