Several studies have reported that dangerousness in the form of interpersonal violence increases when psychotic symptomatology is present. Some offenders also attribute their criminal behavior to symptomatology rather than contextual factors. For example, Camp (2009) studied a group of psychotic male prisoners who reported active psychotic symptoms at the time of committing a criminal offense. These prisoners attributed their criminal behavior directly to their psychotic symptoms or blamed their behavior on auditory hallucinations. Studies of prisoners have shown the prevalence of psychiatric diagnosis to be higher than anticipated, including schizophrenia, major depression, bipolar disorder, organic brain syndrome, substance abuse/dependence, and antisocial personality disorder.
Any illness with a psychological origin, manifested either in symptoms of emotional distress or in abnormal behaviour. Most mental disorders can be broadly classified as either psychoses or neuroses (see neurosis; psychosis). Psychoses (e.g., schizophrenia and bipolar disorder) are major mental illnesses characterized by severe symptoms such as delusions, hallucinations, and an inability to evaluate reality in an objective manner. Neuroses are less severe and more treatable illnesses, including depression, anxiety, and paranoia as well as obsessive-compulsive disorders and post-traumatic stress disorders. Some mental disorders, such as Alzheimer disease, are clearly caused by organic disease of the brain, but the causes of most others are either unknown or not yet verified. Schizophrenia appears to be partly caused by inherited genetic factors. Some mood disorders, such as mania and depression, may be caused by imbalances of certain neurotransmitters in the brain; they are treatable by drugs that act to correct these imbalances (see psychopharmacology). (Brende, :49)
The relationship among diagnosis, crime, and violence in psychiatric patients is, however, ambiguous. Early research reported that a diagnosis of personality disorder was related to higher recidivism rates in mentally disordered offenders. Other researchers posited that psychotic patients, especially those with a diagnosis of paranoid schizophrenia, were more dangerous on release. Severely violent offenders were found to have more delusional beliefs about specific targets and paranoid ideas about significant others being replaced by imposters. Conversely, other studies suggest that a diagnosis of schizophrenia does not increase the risk of violent reoffending and has been found to predict lower risk for future dangerousness than violent offenders without schizophrenia reported that the best predictors of violent recidivism across all groups of offenders were criminal history, antisocial personality or psychopathy, early antisocial behavior, and alcohol abuse. The presence of psychotic symptoms or schizophrenia at the time of the index offense or hospital admission was negatively related to risk. It may be difficult to separate the confounding impact of psychiatric diagnosis in predicting criminal behavior since past criminal offenses have proved to be the best single predictor of future criminal acts. One weakness of the Figley (2008) review is that the number of studies it surveyed containing both violent and mentally ill offenders was relatively small. However, despite the mixed research finding, we agree with Herman (2009) that there does appear to be a significant relationship between major mental disorder and violence, although the exact ...