Parents concordant for major depressive disorder and the effect of psychopathology in offspring

Background. Concordance for major depressive disorder (MDD) between parents could happen for different reasons. Regardless of the origin and the frequ ency of the concordance, the effect on offspring of having two parents affe cted with MDD may be serious. The sex of the affected parent and offspring may also be a important risk factor for MDD in offspring. Methods. We examined the increased risk of psychopathology among offspring of the four parental mating groups: both parents affected with MDD (N = 53) ; only mother affected (N = 31); only father affected (N = 65); and, neithe r parents affected (N = 33). Parents and offspring were assessed by direct interview, conducted blind and independently of each other. Results. Among the four parental mating groups, offspring of both parents a ffected had the highest risk of MDD, anxiety disorder and alcohol dependenc e, and the earliest age of onset for MDD. There were two exceptions: the hi ghest risk of conduct disorder and of drug dependence was in the groups whe re only the father was affected and where only the mother was affected, res pectively. Mother's MDD was a stronger predictor of MDD in male compared to female offspring. Father's MDD was a stronger predictor of MDD in female c ompared to male offspring. Conclusion. Having two parents with MDD increases the risk of psychiatric d isorders in offspring. A clear dose-response relationship between the numbe r of affected parents and psychiatric disorders in offspring was observed. The sex of the affected parent and of the offspring is important in determi ning the risk to offspring. For an examination of the risk to psychopatholo gy in offspring, diagnosis status of both parents should be considered.