Study of family history in seasonal affective disorder

Objective: In our investigation we assessed the risk of morbidity for psych iatric disorders among the first-degree relatives of patients with seasonal affective disorders (SAD) and compared it with a control group of patients suffering from nonseasonal mood disorders (NSMD). Methods: Over a period o f 12 months (June 1994 to May 1995) we recruited patients consecutively adm itted to our psychiatric university outpatient clinic in a prospective stud y. All patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, revised 4th edition. A total of 344 patients pr esented themselves with a diagnosis of affective disorder. Out of these, 36 were diagnosed as having SAD. From the same group of 344 patients, we sele cted a matched control group of 36 patients suffering from NSMD. The experi mental and control groups were matched according to sex, age, severity of i llness and number of siblings. Results: There was no significant difference concerning the lifetime prevalences for psychiatric disorders among the fi st-degree relatives in both groups (SAD = 16.5% and NSMD = 19%). Conclusion : It seems that there is no difference in familiarity for psychiatric disor ders between SAD and NSMD. Copyright (C) 2001 S. Karger AG, Basel.