Aims: The aims of this study were to examine the prevalence and severity of aggression in patients with first-episode psychosis and to identify the association between aggression and sociodemographic and clinical factors. Methods: Consecutive patients with first-episode psychosis admitted to the Early Psychosis Intervention Programme, Singapore, were assessed for a history of aggressive acts. Diagnosis was confirmed using the Structured Clinical Interview for DSM-IV and psychopathology was assessed using PANSS.

Results: Of the 146 patients, 63.0% had no history of aggressive acts, 13.7% demonstrated severe aggression (defined as weapon use, sexual assault or victim injury) and 23.3% had lesser aggression (all other acts of aggression). Patients with aggression had a significantly longer duration of untreated psychosis (DUP) than those with no history of aggression (p ¹/4 .01). The mean total PANSS scores did not differ significantly among the three groups. However, the General Psychopathology scores and the scores for ‘hostility’, ‘poor impulse control’, ‘lack of insight and judgement’ and ‘somatic concern’ were all significantly elevated in patients with aggression (p < .05).

Conclusion: The significant association between aggression and longer DUP once again reiterates the need for early detection and effective management of first-episode psychosis.