The structure of Thalbourne's brief Manic-Depressive scale.

Data from 1376 respondents on a 1994 scale to measure depressive and manic experiences devised by Thalbourne, Delin, and Bassett (1994) were analyzed. Internal consistency reliability estimates for the Total scale (.66), the Depressive subscale (.63), and the Manic subscale (.45) were poor to marginal, and a confirmatory factor analysis did not support the two-subscale structure of the scale. These results, considered in conjunction with those of previous psychometric analyses of the Manic-Depressive Scale, cast doubt on its usefulness for research and clinical use.