Mood-induced changes on the Implicit Association Test in recovered depressed patients.

A mood induction paradigm was used to examine dysphoria-related changes in two types of cognitive processing in individuals who had previously experienced depression. Formerly depressed patients (n = 23) and never-depressed controls (n = 27) completed the Dysfunctional Attitudes Scale, a self-report measure of effortful processing, and performed the Implicit Association Test, an automatic-reaction time task that measures evaluative bias, before and after a negative-mood induction. The formerly depressed group showed both an increase in endorsement of dysfunctional attitudes and a more negative evaluative bias for self-relevant information after the induction, relative to controls--however, there was no association between the mood-linked changes observed on these two measures. The shift in evaluative bias shown by the formerly depressed group was similar to that seen in a group of 32 currently depressed individuals. These findings suggest that even a mild negative mood in formerly depressed individuals can reinstate some of the cognitive features observed in depression itself.

Cognitive therapy for bipolar depression: a pilot study.

OBJECTIVE: While the efficacy of cognitive-behaviour therapy (CBT) for the treatment of acute unipolar major depression is well-documented, there is almost no data evaluating its utility in the treatment of bipolar depression. This pilot study compares the efficacy of CBT combined with mood-stabilizer pharmacotherapy for bipolar depression and CBT alone for unipolar depression. METHOD: A matched-case control design was used to evaluate outcomes following 20 sessions of CBT in 11 depressed bipolar patients and 11 matched recurrent unipolar depressed control subjects. RESULTS: Bipolar depressed patients achieved similar levels of reduction in depressive symptoms following CBT, as did the unipolar depressed group. However, on measures of more pervasive dysfunctional attitudes, bipolar patients did not improve to the same degree. CONCLUSIONS: Preliminary findings suggest that CBT warrants further investigation as an effective psychosocial intervention for depression in bipolar patients already receiving ongoing mood-stabilizing pharmacotherapy.

Differential cognitive response to a mood challenge following successful cognitive therapy or pharmacotherapy for unipolar depression.

This study examined the nature of cognitive reactivity to mood changes in formerly depressed patients. Patients who recovered either through cognitive-behavior therapy (CBT; N = 25) or through pharmacotherapy (PT; N = 29) completed self-reported ratings of dysfunctional attitudes before and after a negative mood induction procedure. In response to similar levels of induced sad mood, PT patients showed a significant increase in dysfunctional cognitions compared with patients in the CBT group. To evaluate the effects of such cognitive reactivity on the subsequent course of depression, follow-up analyses reassessed 30 patients several years after initial testing. Results indicated that patients' reactions to the mood induction procedure were predictive of depressive relapse. These findings argue for differential effects of treatment on cognitive reactivity to mood induction and for the link between such reactivity and risk for later depressive relapse.

A cognitive science perspective on kindling and episode sensitization in recurrent affective disorder.

A cognitive science analysis of the interaction between psychological stress and the neurobiology of affective illness highlights a number of mechanisms relevant to the study of recurrence in major depressive disorder. It builds on observations previously offered by Post (1992) regarding the importance of kindling and sensitization effects in determining activation of neural structures, and proposes a model of knowledge structure activation that follows similar parameters. Vulnerability to depressive relapse/recurrence is determined by the increased risk of particular negative patterns of information processing being activated in depressed states. As is found in studies of kindling and behavioural sensitization, the likelihood of cognitive patterns being activated is dependent on the frequency of past usage, and increased reliance on these patterns of processing makes it easier for their future activation to be achieved on the basis of increasingly minimal cues. This model suggests that the processes related to relapse/recurrence and episode onset may not be isomorphic and, as such, treatments that emphasize relapse prevention strategies should take this distinction into account.

Effects of self-generated sad mood on regional cerebral activity: a PET study in normal subjects.

This study investigated the cerebral regions modulated by self-generated sad mood in normal subjects. Eleven healthy men experienced a temporary sad mood by recalling sad personal memories. Two control states were used for comparison: a resting condition, and a condition involving the recall of affectively neutral personal events. Regional cerebral blood flow (rCBF) images were obtained using [15O]-H2O Positron Emission Tomography. A statistical comparison of the images during negative mood and neutral recall conditions revealed that sad mood was associated with a decrease in rCBF in the left dorsolateral prefrontal, left medial prefrontal, and left temporal cortex; no increase in activity was noted in this comparison. Our results are consistent with the noted left prefrontal decrease in metabolism found in depressed patients through a variety of methodologies; however, our results contrast with findings of increased left or bilateral prefrontal activity in transient induced negative mood states reported for women (George et al., 1995, Am J Psychiatry 152:341-341) and for mixed-gender (Pardo et al., 1993, Am J Psychiatry 150:713-719) subject groups. The study brings to light a number of methodological issues, including the crucial importance of the baseline condition used for the isolation of the emotional components of a given task.

A priming methodology for studying self-representation in major depressive disorder.

The authors investigated processing of self-descriptive emotional information in depression using a modified Stroop color-naming task. Depressed (n = 58) and nondepressed control (n = 44) participants were required to name the color in which positive and negative adjectives, differing in the degree to which they described the person, were presented. These target adjectives were primed by emotional phrases that also varied according to degree of self-reference. Analyses indicated that depressed participants showed slower color-naming latencies for self-descriptive negative targets primed by self-descriptive negative phrases than for any other prime-target condition. No effect of prime-target relation was found for positive material with depressed participants, and nondepressed controls showed no effect of prime-target relation for material in either valence. These results support the hypothesis that negative information about the self is highly interconnected in the cognitive system of depressed patients.