Family History of Mood Disorders as a Risk Factor for Recurrent Depressive Disorder and Bipolar Disorder: Results of Cross-Sectional Study

Abstract

Background: affective disorders (AD) are often aggregated in families among relatives of several generations. It suggests the presence of genetic risk factors for recurrent depressive disorder (RDD) or bipolar affective (BD) disorders.The objective: to assess the risks of affective disorders in individuals with a positive family history, as well as to analyze the clinical characteristics of RDD and BD in family cases.Participants and method: this family cross-sectional study included 36 families with affective disorders (36 probands with AD and 68 relatives), as well as 23 families for the comparison group (23 probands without affective disorders and 53 relatives). The final sample size was 180 people. The study used a case report form developed by the authors, as well as a semi-structured MINI interview (Mini International Neuropsychiatric Interview).Results: it was revealed that a family history of AD is a significant risk factor for RDD or BD in probands. The risks of AD based on the assessment of familial recurrence risk in probands with a burdened family history were also higher than in the general population. When comparing probands with AD with their relatives who had RDD or BD diagnoses, it was found that the age at onset of the underlying disease was significantly less in patients with BD, and probands with BD had significantly longer hypo-/manic episodes. This fact may indicate an aggravation of the course of these pathologies in persons with a positive family history.Conclusion: a burdened family history is an important clinical predictor of the development of AD and their subsequent course. Further multicenter family studies on the Russian population are needed to increase the sample size and analyze the features of aggregation in families of RDD and BD separately using modern molecular genetic methods.