Disproportionality of Depressive Reactions and the Process of Change in Cognitive Behavioral Therapy for Depression.

Background: The proportionality of depressive reactions to stress was long considered an essential feature of clinical depression. Although judgments of the proportionality of depressive reactions have been effectively removed in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), important empirical questions remain about the information that such judgments might convey.

Methods: In Study One, we tested the factor structure of a brief self-report measure of disproportionality, the Proportionality of Depressive Reactions-Self-Report (PDR-S) and evaluated its relationship with measures of adaptive and maladaptive coping in a sample of 616 undergraduate students. In Study Two, we evaluated the role of disproportionality in understanding the impact of cognitive change procedures on client's experience of cognitive change. We evaluated this in a sample of 126 clients participating in CBT for depression.

Results: In Study One, evaluation of the PDR-S revealed good model fit for a single factor solution. The PDR-S was positively related to cognitive reactivity and maladaptive coping responses; it was negatively related to adaptive coping. Most relations were still significant when neuroticism and depressive symptoms were included as covariates. In Study Two, disproportionality moderated the relation between cognitive change procedures and cognitive change, with a stronger positive relationship when participants self-reported a more disproportionate depressive reaction.

Conclusions: Our findings support the use of the PDR-S as a brief measure of disproportionality. Initial evidence shows that the effect of cognitive change procedures on cognitive change is stronger among those self-reporting a more disproportionate depressive reaction.