Certain aspects of the personality may be associated with the vulnerability to develop depression. A sib-pair method has been used to examine the familiality of the 7 scales of the Temperament and Character Inventory (TCI) and whether this could be related to the genetic vulnerability to develop depression.
Probands with depression and their nearest-aged siblings from Wales were compared with healthy control probands and their nearest-aged siblings on the TCI and measures of depressed mood.
All 7 scales of the TCI were familial, and scores on 6 of the scales were similar to US population scores. However, the Welsh subjects' scores on the self-transcendence scale were markedly lower than the US mean, suggesting strong cultural or national influences on this measure. Harm avoidance scores were substantially influenced by current and past depression, but this scale also showed stable traitlike characteristics that are likely related to the genetic vulnerability to depression. Novelty seeking and self-directedness were also partly state-dependent and were negatively correlated with low mood; high scorers may be resilient to the development of depression. High reward dependence may also protect against the development of depression and is unrelated to mood state. The cooperativeness, persistence, and self-transcendence scales appear to have a limited relationship with the development of depression.
Harm avoidance, reward dependence, novelty seeking, and self-directedness have traitlike characteristics that are related to the familiality of depression. Cooperativeness, self-transcendence, and persistence are also familial, but this appears to be unrelated to depression.