Independent dimensions of depression: A factor analysis of three self-report depression measures

Abstract

Covariance studies of objective depression measures have concentrated on total scores. This approach is relatively insensitive in specifying whether these instruments measure the same sub-aspects of depression. To investigate this question, a factor analysis was performed on the items of the Beck Depression Inventory and the Zung Self-Rating Depression Scale and lists A, B, C, and D of the Lubin Depression Adjective Check Lists. Ss were 91 college students and 29 correctional institution inmates. Four clearly interpretable multimeasure factors resulted from a Varimax rotation. The most salient factor was labeled „Depression: Affective Malaise.” Earlier studies also have shown this to be a dominant and reliable dimension of depression. The other factors were: „Suicidal Ambivalence,” „Appetite-Weight Loss,” and „Fatigability.” Females showed greater Fatigability associated with depression. Factors specific to the Beck and Zung measures also were found, which suggests that the different emphases of these instruments, intensity/severity vs. frequency of symptoms, may contribute very specific depression indicators. This may indicate that both intensity and frequency of symptoms ought to be considered to obtain a „best” objective measure of depression.