To explore the types of cognitive changes that result from cognitive therapy (CT) for depression, the authors assessed whether people engaging in CT showed changes in maladaptive beliefs and/or their use of CT techniques for coping with negative thinking, and whether these changes related to improvements in depressive symptoms.
The Ways of Responding Scale (WOR) assesses people’s responses to six hypothetical, adverse scenarios and was used in the study to examine people’s ability to apply CT coping techniques. Maladaptive beliefs were measured using both a self-report measure (the Dysfunctional-Attitude Scale; DAS) and a computer-based test of reaction times to different words that the authors adapted to measure how valued participants believed they were to others (the Valued-Implicit Association Test; Valued-IAT). The Hamilton Rating Scale for Depression (HRSD) and the Beck Depression Inventory-2nd Edition (BDI-II) were used to assess depressive symptoms.
86 people were recruited from the community but 19 were excluded (primarily for not having a diagnosis of major depressive disorder) and 23 did not complete the study. A demographically-matched sample of 44 people without a history of depression were also recruited.
The authors made three predictions: (1) participants with depression would show poorer coping skills and more maladaptive beliefs than people without depression; (2) participants engaging in CT would show improvements on the WOR, IAT and DAS; and (3) these improvements would be associated with improvements in depressive symptoms.
The first prediction was tested with a non-experimental design; comparing the two samples at baseline. The second prediction was tested using a repeated-measures design; using the t-statistic to assess outcomes of participants with depression before and after 16 weeks of CT. The third prediction was tested using a regression design; examining outcomes through therapy using hierarchical-linear modelling.
The results supported the first prediction. However, the second and third predictions were only partially supported. There was a large, significant pre- to post-therapy improvement in WOR scores and a medium, significant improvement in DAS scores, both of which were related to greater improvements in depression symptoms. However, there was not a significant change in Valued-IAT scores which, in contrast to the DAS results, suggested maladaptive beliefs persisted after CT therapy.
Despite acknowledging the limitations, the authors concluded the results highlighted the therapeutic importance of patients learning coping skills in CT.