Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Cognitive theorists hypothesize the existence of a causal cognitive vulnerability for depression that exists as either a continuously observable trait-like difference (i.e., the main-effects model) or a latent factor observable only in interaction with life events or mood (i.e., the interaction effects model). The current investigation examined the main-effects model and one form of the interaction-effects model that emphasizes current mood as the activator of latent cognitive vulnerability, the Differential Activation Hypothesis (DAH). When primed by sad mood, vulnerable individuals purportedly process environmental information in a manner similar to currently depressed individuals, making them more vulnerable for depression.;Studies of cognition in depressed, remitted and nondepressed subjects have been criticized for not priming subjects at test times or for using state-like symptom descriptor stimuli to assess trait-like differences. In the current investigation, depressed, remitted and never depressed women completed self-report questionnaires and two computerized tasks, a Stroop task and a deployment-of-attention task (DOAT). Care was taken to evaluate both stage-like and trait-like stimuli, as well as priming individuals, through mood inductions, before cognitive tasks.;Results indicated that subjects' self-reports were predicted only by main effects of mood or diagnostic history, thereby supporting the main-effects hypothesis. When the Stroop task was presented following the DOAT, further support for the main-effects hypothesis was obtained. A weighted reaction time analysis using subjects' self-referent ratings of stimuli was able to differentiate depressed and never depressed subjects' performance, but not previously depressed subjects' performance on the Stroop. Subjects' responses to the DOAT conformed to predictions made from both the main-effects model and the DAH for trait-like but not for state-like stimuli. Never depressed subjects and unprimed remitted subjects evidenced a protective bias by focusing attention away from trait-like negative-content stimuli, while primed previously depressed subjects and currently depressed subjects were unbiased.;Overall, modest support for the DAH was obtained while studies more consistently pointed towards support for the main-effects hypothesis. Important stimulus characteristics were identified, implications for understanding depression and limitations of the current investigation were discussed.



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