Before addressing the relation between personality and depression, several conceptual issues regarding the construct of personality should be considered. First, personality has traditionally been conceptualized as having two components: temperament, which refers to biologically based, early-emerging, stable individual differences in emotion and its regulation, and character, which refers to individual differences due to socialization. However, the distinctions between these constructs are questionable, as a large body of evidence has accumulated indicating that personality traits have all the characteristics of temperament, including strong genetic and biological bases and substantial stability over the lifespan (Krueger & Johnson 2008, Watson et al. 2006). Hence, the terms “personality” and “temperament” are now often used interchangeably (Caspi & Shiner 2006, Clark & Watson 1999). As most research on personality in childhood has been conducted under the temperament rubric, in this review we refer to this work using the term “temperament” and reserve the term “personality” for discussing the literature on adolescents and adults. However, this is intended to reflect traditional usage rather than a conceptually meaningful distinction.
