People with bipolar disorder vary significantly from their unaffected relatives, and from healthy controls, on several measures of personality, a study shows.
Furthermore, genetic analysis revealed suggestive linkage peaks for those traits that were heritable, potentially proving useful for the identification of genes underlying susceptibility to bipolar disorder.
“The results of our analyses suggest that personality dimensions may have utility in dissecting the genetic architecture of BD [bipolar disorder],” the researchers write in the Journal of Affective Disorders.
Personality scores on the Temperament and Character Inventory (TCI) were collected from 428 members of 101 families in which one or more people had a bipolar diagnosis or major depressive disorder. An independent sample of 53 control participants with no personal or family history of mental illness was also recruited.
The TCI is a self-administered true/false questionnaire that assesses personality in seven dimensions. It assesses four temperament dimensions – novelty seeking, harm avoidance, reward dependence and persistence – and three character dimensions – self-directedness, cooperativeness and self-transcendence.