Heterogeneity of violence in schizophrenia and implications for long-term treatment

Aims: Most patients with schizophrenia are not violent. However, persistent violent behaviour in a minority of patients presents a therapeutic challenge. Published treatment guidelines and most pharmacological and epidemiological literature on violence in schizophrenia treat overt physical aggression as a homogeneous phenomenon. The aim of this review is to address the subtyping of violent behaviour in schizophrenia, and to relate the subtypes to treatment. Method: Literature describing subtypes of violence in schizophrenia and the treatment of this problem was reviewed. 'Schizophrenia', 'violence', 'aggression', 'hostility' and 'personality disorders' were the principal search terms describing behaviours. Generic names of individual atypical antipsychotics and mood stabilisers were used in treatment searches. Results: There are at least three aetiological subtypes of violence in schizophrenia (i) that related directly to positive psychotic symptoms, (ii) impulsive violence and (iii) violence stemming from comorbidity with personality disorders, particularly psychopathy. Current treatment of violence in schizophrenia relies on antipsychotics and mood stabilisers. The evidence of effectiveness is relatively strong for clozapine, but inconsistent for other treatments. No systematic recommendations relating the treatment to aetiological subtypes of violence were found. Discussion: The inconsistent effectiveness of the current treatments of violent behaviour in schizophrenia is due, at least in part, to the aetiological heterogeneity of that behaviour. We should not expect that any given pharmacological treatment will be equally effective in reducing violent behaviour caused by psychosis, impaired impulse control or personality disorder. Conclusions: Violence in schizophrenia is aetiologically heterogeneous. This heterogeneity has therapeutic implications that impact clinical practice today and should be further explored in future studies.