Most of the psychological and neuro-psychiatric research showed that there is a strong connection between mental illness and violent, criminal tendencies or behavior of the aggressor, which is intuitively socially agreed upon. The latest study of crimes realized on a sample of people with neurological and psychiatric dysfunctions showed that only 7,5 per cent of the cases were triggered by actual symptoms of their illness, according to American Psychological Association (APA).
The number of analyzed crimes is 429 committed by 143 subjects with three main types of mental illnesses and revealed that no more than 3 per cent of the crime rate was directly linked to symptoms of depressions, while 4 per cent were connected to symptoms of schizophrenia. Ten per cent of the cases were linked to bipolar disorder. The lead researcher, Jillian Peterson, PhD., confirmed that the results of the study were representative to the cases he has encountered during his career. ‘The vast majority of people with mental illness are not violent, not criminal and not dangerous’, he declared about both the study he conducted and the realities he has experienced as a professional.
The research consisted of a two-hour interview covering issues of their medical symptoms and criminal records for up to 15 years in their past. The study, which APA published in Law and Human Behavior, is one of the first to draw a correspondence between criminal behavior and mental illness on an extended period of time of the offender’s life. Another distinct trait of the study (besides the larger perspective) were the counter-intuitive conclusions. No predictable patterns connecting mental illness with criminal conduct were found concerning the evolution of the symptoms over time. Moreover, over two thirds of the subjects who committed crimes related to their symptoms were also found guilty for other crimes unrelated to their medical condition. The underlying conditions for the other felonies were unemployment, poverty, homelessness as well as drug abuse, as the study suggests. In most of the cases, the medical condition was one of the many contributing factors and not the main reason for the behavior, according to Peterson.
Another method used in the research was reviewing the criminal history and the social worker files in order to help rating the crimes based on the factual association with the medical symptoms of the disorders. The scale of the rating was from: ‚unrelated’ to ‚mostly unrelated’‚ mostly related’ and ‚directly related’. Qualifying a crime as ‚mostly (un)related’ to a symptom was based on the connection with the disease, without considering it as the unique factor for the abusive behavior. Whenever the qualification of the crime as being ‚directly related’ to the disease was combined to clues indicating a ‚mostly related’ causality, the percentage of mental illness inter-related to crimes became from 7,5 per cent to 18 per cent, or less than one in five of the analyzed situations. In order for the sample to be representative for the population with mental disorders who is imprisoned, two thirds of the subjects were male of an average of 40 years.
Serious offenses were not included in the study, since the offenders were not adjudicated by the mental health court, but the participants to the study did have the freedom to describe other prior violent crimes they committed. The study did not investigate the influence of drug abuse on the mentally ill offender in connection with their criminal behavior.
Cognitive-behavioral treatment about criminal thinking, anger management and other behavioral problems was recommended, however, in order to reduce recidivism for mentally ill offenders beyond the medical treatment they are currently administrated. Recidivism, as Peterson also suggests, could also be reduced by addressing basic needs of the offenders after the incarceration, including drug treatment, housing and employment support.
More than 1,2 million people with mental illness are detained in prisons in the United States of America, as the federal Bureau of Justice Statistics declared, while the situation of probation or parole is at two to four times higher than the rate for the clinically healthy population.