Substance misuse, psychiatric disorder and violent and disturbed behaviour.

Abstract

Epidemiological studies suggest schizophrenia and substance misuse to be associated with a higher rate of violence and crime. The literature was evaluated to assess whether people with schizophrenia who use substances have an increased risk for violence and disturbed behaviour. A detailed Medline analysis was performed and relevant studies were reviewed. A large number of studies have linked substance misuse in schizophrenia with male gender, high incidence of homelessness, more pronounced psychotic symptoms, non-adherence with medication, poor prognosis, violence and aggression. The latter has been proved by clinical, epidemiological and longitudinal prospective studies of unselected birth cohorts. The increased risk for aggression and violent acts cannot be interpreted only as a result of poor social integration. Male gender, more severe psychopathology, a primary antisocial personality, repeated intoxications and non-adherence with treatment are important confounding variables. Substance misuse has been shown consistently to be a significant risk factor for violence and disturbed behaviour. Future research should try to evaluate possible pharmacological and psychosocial treatment approaches.