Endorsement of dysfunctional beliefs depends on current mood state.

In two studies we tested the hypothesis that endorsement of dysfunctional beliefs depends on current mood state for persons who are vulnerable to depression. The first study showed that reports of dysfunctional beliefs vary with spontaneous diurnal mood fluctuations in 47 depressed psychiatric patients. The effect of mood state was highly significant (p less than .01); dysfunctional thinking increased when mood was worst and decreased when mood was best. The second study conceptually replicated this finding in a population of asymptomatic subjects. As predicted, reports of dysfunctional beliefs varied as a function of mood state in 14 persons who had experienced a depressive episode but not in 27 who had never been depressed. These findings support the cognitive theory of depression, which proposes that dysfunctional beliefs are vulnerability factors for depression but also that reporting of dysfunctional beliefs depends on current mood state.