Temperament among offspring at high and low risk for depression.

The purpose of this study was to examine relationships between parental depression, offspring temperament, and offspring major depressive disorder (MDD), and to determine whether difficult temperament, as measured by the Dimensions of Temperament Survey (DOTS), mediates the relation between parental MDD and offspring MDD. Offspring (n=169) of depressed or never depressed parents were followed over approximately 20 years and were blindly assessed up to 4 times (Waves 1 to 4) using semi-structured interviews. Offspring completed the DOTS at the time of first or second assessment. The results showed: (1) high-risk offspring with one or more depressed parent were significantly more likely than offspring with neither parent depressed to have a difficult temperament; (2) offspring with a difficult temperament were more than twice as likely as those with an easy temperament to develop a MDD; and (3) difficult temperament explained more than 10% of the association between parental depression and new onsets of MDD in offspring. The findings suggest that offspring temperament is associated with development of MDD and that difficult temperament at least partially mediates the relationship between parental depression and offspring depression. When identifying those at greatest risk for MDD, measures of temperament could serve as a useful supplement to family psychiatric history of MDD.