Previous studies have demonstrated that family history is associated with earlier age at onset, severity of positive and negative symptoms, and the duration of untreated illness. Hereditary factors may contribute a vulnerability for antisocial and/or violent behaviour per se, and for other stable characteristics such as aggressive behaviour.

To analyze the impact of family history of schizophrenia and aggressive behavior among members of family on severity of disease and aggressive behavior of patients.

The study population consisted of 120 male schizophrenic patients classified into non-aggressive (n = 60) and aggressive (n = 60) groups, based on indication for admission in hospital (aggression/anything else but aggression). For severity of disease, we assessed psychopathology using the Positive and Negative Syndrome Scale (PANSS), the number of hospitalizations and the total equivalent dose of therapy (collected from medical record). The presence of a family history and aggression in family was assessed using a semi-structured interview of patients and, when available, family members.

Twenty-seven (22.5%) participants were determined to have at least one family member with schizophrenia or another psychotic disorder, with no difference between aggressive (10%) and non-aggressive (12.5%) group. There was no significant interaction between family history and severity of disease (PANSS, number of hospitalizations, total equivalent dose of therapy). Aggressive behaviour in first-degree family member had no influence on aggressive behaviour of patients with schizophrenia.

Family history of schizophrenia does not affect the severity of disease nor aggressive behaviour.

The authors have not supplied their declaration of competing interest.