The participants were all ages 14-24 years (average 19.2 years) and were inmates of a prison for youthful male offenders. Sixty-one of the inmates with mental disorders and 74 of the 150 inmates without mental disorders had committed violent crimes, indicating a trend toward fewer violent crimes among those without mental disorders. No statistically significant differences existed in the violent and nonviolent groups in most diagnostic categories, the Beck Hopelessness Scale, the IQ scale, the MMPI scores, job stability, and whether or not they were treated by a psychiatrist. However, some significant differences existed. Those who had committed violent crimes were significantly younger than those who had committed nonviolent crimes, regardless of psychiatric versus nonpsychiatric category. All of the small number of inmates with a diagnosis of paranoid schizophrenia had committed violent crimes, while all those with depression had committed nonviolent crimes. Further research is recommended on several issues. Tables and 10 references (Author abstract modified)