The article is devoted to the analysis of aggressive criminal behaviour in mentally ill persons.

To develop effective measures to prevent committing dangerous assaultive acts in mentally ill persons.

To study personal, social and clinical characteristics of the disease in mentally ill persons who have committed dangerous assaultive acts.

We examined 25 mentally ill persons that had committed dangerous assaultive acts and have been found insane as regards their offence. The research involved clinical psychopathological study and follow-up.

In 19 cases (76%), schizophrenia was diagnosed; in 3 cases (12%), organic cerebral lesions of traumatic or mixed etiology; in 1 case (4%), epilepsy; and in 2 cases (8%), delirium tremens.

Of the subjects, 21 (84%) had a high education level; 3 (12%), a higher education level (university); and 1 (4%), incomplete high education.

At the time of committing the offence, 9 subjects (36%) had a permanent job; 3 subjects (12%) had seasonal jobs; 10 subjects (40%) didn’t have any job at all; and 3 (12%) subjects were recognized as mentally disabled.

At the time of committing the offence, 13 subjects (42%) were not registered in a public psychiatrist's office.

The personal and social characteristics of the mentally ill offenders have clearly demonstrated the prevalence of poorly educated, socially maladapted persons among them. Most of the subjects had not been registered in a psychiatrist's office. A vast majority of dangerous assaultive acts are committed by schizophrenics in an acute stage of the disease.