August 1993

The Roscommon Family StudyII. The Risk of Nonschizophrenic Nonaffective Psychoses in Relatives

Author Affiliations

From the Departments of Psychiatry and Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond (Dr Kendler); St Patrick's Hospital and the Western Health Board, Castlerea, Ireland (Drs McGuire and Spellman); Dave Garroway Laboratory for the Study of Depression, Pennsylvania Hospital, and Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia (Dr Gruenberg); The Health Research Board, (Ms O'Hare and Dr Walsh), and St Loman's Hospital (Dr Walsh), Dublin, Ireland.

Arch Gen Psychiatry. 1993;50(8):645-652. doi:10.1001/archpsyc.1993.01820200059006

Objective:  We sought to clarify the familial relationship between the nonschizophrenic, nonaffective psychoses (schizoaffective disorder [SAD], schizophreniform disorder, delusional disorder, and atypical psychosis) and schizophrenia and affective illness (AI).

Design:  A case-controlled epidemiologic family study using DSM-III-R criteria.

Results:  Compared with relatives of unscreened controls, the risk of nonschizophrenic, nonaffective psychoses was significantly elevated in relatives of probands with schizophrenia, SAD, schizotypal personality disorder, and psychotic AI. No significant elevation in risk to these disorders was seen in relatives of probands with nonpsychotic AI. The risk for SAD alone was significantly increased in relatives of probands with psychotic or bipolar AI.

Conclusions:  The nonschizophrenic, nonaffective psychoses have a significant familial relationship with both schizophrenia and schizotypical personality disorder. Schizoaffective disorder, as defined by DSM-III-R, shares familial etiologic factors with at least some forms of AI.