It is a common view that mental illnesses are widely associated with dangerous, threat-posing behavior and law-breaking.

The paper analyzes the problem of law-breaking by the mentally disordered.

The analysis of cases concerning compulsory psychiatric treatment or confinement in a medical institution on the grounds of mental incompetence to commit an offence or mental unfitness to stand the trial obtained from the court and the public prosecutor’s office in Silesia Region from 2007 to 2009.

14 cases were analyzed. All the offenders were male, mean age was 44,6. All the offenders were diagnosed by psychiatrists, most of them with schizophrenia (n = 10 cases). Other diagnoses included paranoid personality disorder (n = 1), bipolar affective disorder with manic episode (n = 1), schizoaffective disorder (n = 1), delusional disorder (n = 1). 9 out of 14 offenders were diagnosed prior to the offence, some of whom were also hospitalized (n = 5). 8 of analyzed cases concerned use of violence, 3 concerned larceny, 2 concerned posing a threat to others’ life or health and 1 concerned fraud. 2 of the offenders were previously sentenced for other offences. 12 of the offenders were compulsory treated by psychiatrists, 10 out of whom is still hospitalized.

The small number of the cases analyzed (14 cases in the whole of 5000) suggests that mentally disordered persons do not break law often. There seems to be a higher risk associated with male gender, though. Also, the frequency of violent acts and offences committed despite previous treatment is disturbing.