Personality and the predisposition(s) to bipolar disorder: heuristic benefits of a two-dimensional model

The aim of this study was to model normal personality correlates of the predisposition(s) to bipolar disorder (BD), and in so doing explore the proposition that the tendency to bipolar depression [trait depression (T-Depression)] and the tendency to mania [trait mania (T-Mania)] can usefully be viewed as separable but correlated dimensions of BD predisposition.

A well student sample (n = 176, modal age 18-25 years, 71% female) completed the NEO Personality Inventory-Revised and the General Behavior Inventory.

A good-fitting model (normed chi2 = 0.60, significance of chi2 = 0.73) was identified in which T-Depression was determined solely by neuroticism, while T-Mania was determined by extraversion and (negative) agreeableness. The pathway from T-Depression to T-Mania was also significant (standardized regression weight = 0.80), with a weaker significant reciprocal path (coefficient = 0.27). A model in which bipolar vulnerability was represented as a single dimension (T-Bipolarity) also provided a good fit to the data, but provided less heuristic power.

Predisposition to BD can be usefully understood in terms of two reciprocally related dimensions of vulnerability (T-Depression and T-Mania), which can be separated on the basis of their personality correlates.