Verbal Intelligence and Criminal Offending Among Men With Schizophrenia

Abstract

Background: There is consistent evidence for an association between schizophrenia and criminal offending. With better knowledge of the relation between schizophrenia and criminal offending, better and more cost-effective methods for prevention of criminal offending could be expected and public fear of mentally ill persons being reduced. The overall aim of the present study was to advance knowledge regarding risk factors or potential risk factors for criminal offending among males with schizophrenia. Specifically, one aim was to investigate the associations between low verbal intelligence and early-onset, persistent offending among males with schizophrenia. Another aim was to validate alcohol use typologies among males with schizophrenia. Methods: The study was based on data provided from the Comparative Study of the Prevention of Crime by Mentally Ill Persons, an international, multi-site follow-up study on patients from forensic psychiatry (n = 186) and patients from general psychiatry (n = 122), led by Professor Sheilagh Hodgins. All participants underwent extensive assessment at discharge. The instruments used were SCID, WAIS-R, PCL-R, PANSS, and NEO-PI-R. Information on background, criminality and follow-up data was collected from all available sources, including the participant and a family member, staff, and records. In Paper I, base-line data from discharge was used along with historical data. The participants of Paper I were men with schizophrenia spectrum disorders (n = 219). Data were analysed by uni-variate methods and by standard multiple regressions. In Paper II, base-line data, historical data and prospective measures from the follow-up were used. The participants of Paper II were men with schizophrenia spectrum disorders and alcohol use disorders (n = 139). Data were analysed by uni-variate methods and by k-means cluster analyses. Results: Low verbal IQ did not increase the risk for criminal offending among men with schizophrenia spectrum disorders, but among those who did offend it was associated with a younger age at first conviction for a non-violent crime (Paper I). Widely used uni-dimensional and multi-dimensional typologies of alcohol use disorders, developed in settings with non-mentally disordered individuals, were replicated and showed at least some degree of concurrent validity in a sample of men with schizophrenia spectrum disorders and alcohol use disorders although the predictive validity was weak (Paper II). Conclusions: The results of the study suggest that individuals with schizophrenia constitute a heterogeneous population. Treatment planning must be kept at an individual basis and set out from qualified and thorough assessments of individual needs. When assessing risk for criminal offending, the conditional nature of risk factors must be considered. Finally, programmes for crime prevention (risk management) should be individually designed as well, to ensure that all interventions include the necessary features and are kept at a proper level.

Criminal offending and distinguishing features of offenders among persons experiencing a first episode of psychosis

“…In the present study, African‐Caribbean ethnicity was associated with offending, as it was in a study that recruited patients experiencing a first episode of schizophrenia from 1965 to 1984 in the same neighbourhood 42 . However, this is the first study to our knowledge to observe associations between low IQ, or low verbal IQ, and offending among patients with SMI 43 . A meta‐analysis reported lower IQ among broadly defined ‘antisocial’ as compared with ‘non‐antisocial’ persons with schizophrenia 44 .…”

“…42 However, this is the first study to our knowledge to observe associations between low IQ, or low verbal IQ, and offending among patients with SMI. 43 A meta-analysis reported lower IQ among broadly defined 'antisocial' as compared with 'non-antisocial' persons with schizophrenia. 44 In the general population, lower than average verbal IQ is strongly and consistently associated with criminality that onsets in adolescence.…”

The Biology of Childhood Crime and Antisocial Behavior

“…Verbal de fi cits (which may result from posterior temporal and parietal lobe injury) may play a critical role in the development of self-control (Luria, 1966 ) by following verbal instructions and subsequent internalization of verbal-based self-control mechanisms (a process mediated by intact receptive speech, verbal memory, and verbal reasoning). Compromised development may produce a limited repertoire of appropriate verbally mediated behavior, impulsivity, aggression, and hostility (as the condition is exacerbated by environmental in fl uences; Teichner & Golden, 2000 ) , and ultimately socialization failure (Eriksson, Hodgins, & Tenström, 2005 ) . Juvenile offenders with compromised verbal development are generally characterized by reduced verbal intelligence, reading problems, speech delays, and verbal memory dysfunction.…”