The cohorts differed in terms of the diagnoses and the types of offenses. Distributing patients according to first psychiatric diagnoses showed that offender rates varied between the diagnostic categories, especially in the Stockholm cohort. In the latter, the variation in offender rate among diagnoses was sustained when diagnoses other than the first were taken into account and when the female cohort was part of the analyses. The high offender rates were confined to drug addicts, alcoholics, and a small group diagnosed as "pathological personalities." The remainder of the psychiatric inpatients had offender rates only slightly higher than the rest of the cohort. The high-rate psychiatric categories were small, but they were responsible for a considerable percentage of the cohorts total known offenses. This was especially true for certain types of offenses, for those older than 21, and for females. 8 tables, 6 notes, 9 references. (Author abstract modified)