Is Arson the Crime Most Strongly Associated With Psychosis?—A National Case-Control Study of Arson Risk in Schizophrenia and Other Psychoses

Abstract

The association of psychosis with certain serious crimes, such as homicide, has been clearly demonstrated, but it is uncertain to what extent psychotic disorders are associated with arson. We used a case-control design to investigate the association of being diagnosed with schizophrenia and other psychoses and committing arson. Data were obtained from Swedish national registers for criminal convictions, hospital discharge diagnoses (International Classification of Diseases, Ninth Revision [ICD-9], and International Classification of Diseases, Tenth Revision [ICD-10]), and sociodemographic factors for 1988-2000. We included all convicted arson offenders of both sexes in Sweden (N=1689) and compared them with a random sample of general population control subjects (N=40,560). After adjustment for sociodemographic confounders, arson offenders were more likely to be diagnosed with schizophrenia (in men, adjusted odds ratio [OR]=22.6, 95% confidence interval [CI]=14.8-34.4; in women, adjusted OR=38.7, 95% CI=20.4-73.5) or other psychoses (in men, adjusted OR=17.4, 95% CI=11.1-27.5; in women, adjusted OR=30.8, 95% CI=18.8-50.6). Individuals with schizophrenia and other psychoses have significantly increased risks of an arson conviction. These risk estimates are higher than those reported for other violent crimes and place arson in the same category as homicide as crimes that are most strongly associated with psychotic disorders.