Genetic factors and gene-environment interactions together contribute over 80% of the liability for developing schizophrenia. Schizophrenia runs in families and there are significant variations in the incidence of schizophrenia, with urbanicity, male gender, and a history of migration being associated with a higher risk for developing the illness.

To collect anamnestic data on 100 schizophrenic clients attending our psychiatric outpatient services.

To investigate the possible implications of psychiatric familiarity on the severity of the illness.

We defined two distinct subgroups of patients on the basis of familiarity and matched patients for age and illness onset. We estimated the global severity of symptoms on the basis of psychometric results and number of hospitalizations during the last three years. We correlated psychometric scores with familiarity for a psychiatric disease.

We confirmed a higher prevalence of psychiatric diagnoses among patients' families compared to the general population: 29% of our patient sample was found to have at least one parent or brother with a reliable psychiatric diagnosis. Surprisingly, we found that patients with a positive familiarity did not show a worse psychopathological profile compared to patients with a silent familiar history.

Families with a complex psychiatric history, in which more than one component attends our services, are strictly supervised in order to prevent stressful life events, generally more frequent in problematic families. This accurate monitoring may have contributed to the slighter intensity of symptoms found in schizophrenic patients with a positive familiarity for psychiatric diagnoses.