Clozapine-associated reduction in arrest rates of psychotic patients with criminal histories.

OBJECTIVE The authors examined the relationship between treatment with clozapine and rates of arrest of psychotic outpatients with criminal histories. METHOD Patients who had been given a DSM-IV psychotic diagnosis were selected from an urban outpatient clinic database. Background checks performed on 360 patients identified 165 (45.8%) with positive criminal histories in Massachusetts. The authors reviewed the charts of these patients to determine several variables, including whether and when they had received clozapine. A Poisson regression model was used to regress arrest rates against the variables of age, sex, onset of illness, birth cohort, and clozapine treatment. Risk ratios (i.e., percent change in arrest rates) were then calculated by computing the exponential of the Poisson regression coefficients. RESULTS The 165 patients included in the analysis had a total of 1,126 arrests. The mean number of arrests was 6.8. Differences were found between the 65 patients who received clozapine and the 100 patients who did not in number of arrests, sex, and onset of illness. The regression revealed significantly higher arrest rate estimates associated with more recent birth cohort (4.8%) and with onset of illness (64.6%) and lower arrest rate estimates associated with higher levels of education (11.6%), receiving clozapine (32.6%), and receiving clozapine during specific periods of time (68.9%). CONCLUSIONS Clozapine's effect on arrest rates in this group of patients is large enough to warrant further investigation. The data indicate that clozapine may reduce recidivism in subjects with criminal histories who are in need of antipsychotic medication.