It is a common assumption, that whenever a brutal, violent or senseless crime is committed, it is by someone who is mentally ill or sick. Blaming violent and senseless crime on mental disorders may be comforting but it is not necessarily accurate.
Introduction
Crime by mentally ill people has become a matter of heightened public concern in recent years. The inpatient population of mental hospitals in the United States shrunk from a peak of 550,000 in 1955 to 70,000 in 2000. As a result, many severely mentally ill people who in earlier decades would have spent much of their lives as mental hospital patients now live elsewhere. Many cycle through periods of homelessness, brief psychiatric hospitalization, and incarceration in jail or prison (American Psychiatric Association, 2000). The relationship between crime and mental illness is complex. Most crime is committed by people who are not mentally ill. Similarly, most people with mental illness do not engage in criminal behavior.
For a small percentage of people, mental illness so distorts their perception or judgment that it causes them to commit crimes. Most crimes caused by mental illness are public order offenses such as vagrancy and public intoxication, minor property destruction, and minor assaults. Unfortunately, infrequent and highly publicized violent offenses by mentally ill people capture the public imagination and distort perceptions of mentally ill offenders and mentally ill people generally.
A stereotype has developed of the 'insane mass murderer' largely due to the media, however, research evidence suggests that this stereotype is far from accurate. Much research on the link between crime [specifically to this discussion, violent crime] and mental disorder has been conducted, however there are different factors that need to be taken into account when examining this link. Definition of mental disorder is a major one, along with possible uneven sample distributions. Also, there have been changes in mental health and criminal justice policies that have increasingly made hospitalisation restricted to those who are more socially disruptive or dangerous. With these considerations in mind, research evidence can be then be examined. (Patel 2003:195)
Mental Disorders and Crime
Direct measures of the relationship between crime and mental illness are unavailable, because much crime and mental illness go undetected (American Psychiatric Association, 2000). The most authoritative information comes from two types of studies: (1) psychological screening of jail and prison inmates and (2) interviews with the general population. The results of these studies reveal that although people who suffer from serious mental illness are more likely to be arrested than members of the general public, the offenses for which they are arrested are similar to those resulting in arrest among the general public. Mentally ill, homeless people who also use alcohol and illegal drugs are particularly likely to be arrested because their functioning may be severely impaired and they may engage in bizarre or threatening public behavior. About half the people who are homeless are also mentally ill (Lamb and Bachrach, ...