More data point to mental illness as risk for criminality

Belfrage conducted a follow-up study on 1,056 Swedish mental patients diagnosed as having schizophrenia, affective psychosis, or paranoia. Of the patients, 893 were still alive at the time of the follow-up.

"Of those who were still alive ten years after discharge from mental hospitals in 1986, 28 percent were found to be registered for a criminal offense," Belfrage reports. "Among those who were 40 years old or younger at the time of discharge, nearly 40 percent had a criminal record as compared to less than 10 percent of the general [Stockholm] public." In addition, he notes, the most frequently commited crimes were violent ones.

According to Belfrage's data, schizophrenics had a higher rate of criminality than subjects with other forms of mental illness. All of the severely violent crimes committed by Belfrage's mentally ill subjects, including eleven cases of attempted murder or manslaughter, were committed by schizophrenic individuals.

Although the mentally ill patients committed many violent acts, Belfrage notes that for the most part their crimes were minor and typical of "social drop-outs"-for instance, shoplifting or making threatening remarks. "The most frequently occurring crimes in the study group do not reflect the type of criminality that is common in forensic psychiatric populations," he says, "that is, severe violent and sexual crimes."

Belfrage notes that his study has several limitations that would cause criminal behavior in the mental patients to be underestimated. Thus, he concludes, "the figures presented represent only an absolute minimum."

"A ten-year follow-up of criminality in Stockholm mental patients: new evidence for a relation between mental disorder and crime," Henrik Belfrage, British Journal of Criminology, Vol. 38, No. 1, Winter 1998, pp. 145-155. Address: Henrik Belfrage, Karolinska Institute, Stockholm, Sweden.