Prevalence of psychotic and non-psychotic disorders in relatives of patients with a first episode psychosis Kia Faridi a,b,c , Nicole Pawliuk a,c , Suzanne King b,c , Ridha Joober a,b,c , Ashok K. Malla a,b,c, ⁎ a Prevention and Early Intervention Program for Psychosis, Montreal, Quebec, Canada b Department of Psychiatry, McGill University, Montreal, Quebec, Canada c Douglas Mental Health University Institute, Montreal, Quebec, Canada article info abstract Article history: Received 11 August 2008 Received in revised form 29 June 2009 Accepted 6 July 2009 Available online 9 August 2009 Background: Family members of individuals with schizophrenia suffer from elevated rates of schizophrenia-spectrum disorders (SSD) and other forms of psychopathology. However, few studies have examined familial psychopathology in probands with a first episode of psychosis (FEP). We systematically evaluated family history in patients experiencing an affective or non- affective FEP. Methods: The Family Interview for Genetic Studies was used to obtain diagnostic information on all first- and second-degree relatives of probands admitted to a specialized FEP program. Probands were 94 previously untreated patients suffering from a first-episode of affective or schizophrenia spectrum psychosis, aged 14 to 30. The interview ascertained diagnoses of psychotic disorders, affective disorders, substance-use disorders (SUD), and schizophrenia- related personality disorders. Results: One in five probands (19.1%) had a history of psychosis among their first-degree relatives, while 34.0% had any relative with psychosis. Fewer probands had a family history of SSD (7.4% with a first-degree history and 18.1% with a history among any relatives). Over half (53.2%) of probands had a first-degree relative with Major Depressive Disorder, and 38.3% had a first-degree relative with a SUD. Overall, 69.9% of probands had a first-degree relative with a mental disorder. The proportion of probands with a family history of any of these diagnoses did not vary by proband diagnosis (affective or SS Psychosis), though probands with co-morbid SUD were more likely to have a family history of substance abuse. Conclusions: Diverse psychopathology is commonly present in families of FEP patients and may imply a generalized vulnerability to psychiatric disorders to be greater in such families compared to specific vulnerability to SS or affective psychosis. These findings may also have implications for provision of care for the probands. © 2009 Elsevier B.V. All rights reserved. Keywords: Schizophrenia First-episode psychosis Family history Familiality 1. Introduction The familial nature of schizophrenia is well documented, with the most robust evidence emerging from controlled epidemiologic studies (Kendler et al., 1985, 1993a; Tsuang et al., 1980). It has also been demonstrated that other psychotic disorders tend to aggregate in the families of probands with schizophrenia. Kendler used data from the Roscommon Family Study to support the existence of a Schizophrenia Spectrum, consisting of a shared liability between affective psychoses, non- schizophrenic non-affective psychoses, schizotypal and paranoid personality disorders, schizoaffective disorder, and schizophre- nia (Kendler et al., 1995). Most studies confirm that affective illnesses do not form part of the Schizophrenia Spectrum (Kendler et al., 1995; Tsuang et al., 1980), though some studies have reported an increased risk of non-psychotic affective illnesses in the relatives of probands with schizophrenia (Chang et al., 2002; Kendler and Gardner, 1997; Kendler et al., Schizophrenia Research 114 (2009) 57–63 ⁎ Corresponding author. McGill University, Douglas Mental Health Uni- versity Institute, 6875 Boul. Lasalle, Montreal, Qc, Canada H4H 1R3. E-mail address: ashok.malla@douglas.mcgill.ca (A.K. Malla). 0920-9964/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.schres.2009.07.007 Contents lists available at ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres