Can concreteness training alone reduce depressive symptoms? A randomized pilot study using an internet-delivered protocol

It has been shown recently that a specific intervention designed to modify the overgeneralization bias [i.e.; concreteness training (CNT)] can decrease depressive symptoms. The intervention, however, involves multiple components (e.g.; relaxation, problem solving), so it is not clear if the increase in concrete processing is the crucial mechanism in ameliorating depressive symptoms. Using a dismantling design, this online study examined whether targeting only concrete processing in the absence of a therapeutic context reduces depressive symptoms. Forty-two stable dysphoric participants were randomly allocated to either a waiting list or a 7-days concreteness training condition. Compared with the control group, concrete processing training resulted in a significant increase in the concreteness of thinking. No significant differences in autobiographical memory specificity, depressive symptoms, or rumination, however, were obtained post-intervention between the two groups. These findings suggest that concrete processing can be trained, but training effects may not generalize to untrained cognitive contents. The effectiveness of CNT as a standalone treatment for depression may be limited.