Why is rumination unhelpful in adolescents? Two studies examining the causal role of abstract processing.

Rumination is a common feature of depression in adolescents and adults and it is implicated in the maintenance of depression symptoms. In adults, the maladaptive consequences of rumination have been attributed to the abstract processing mode that characterises this thinking style. The question of whether the same is true in adolescents remains unanswered. Here we describe two experimental studies in which adolescents were trained to think in a mode either characteristic of or inconsistent with the abstract processing style observed in depressive rumination, and the effect on social problem-solving and negative future thinking was examined. The two experiments employed a similar design. 11-14 year olds scoring in the upper and lower quartile on a measure of depression were trained to engage in an abstract or concrete processing style and then carry out a social problem-solving (Study 1) or future thinking (Study 2) task. Adolescents were worse at social problem-solving and had more negative (but not fewer positive) future thoughts when engaging in abstract processing compared to concrete processing, regardless of their current level of depressive symptoms. The finding remained when controlling for state mood. Our findings suggest there may be value in targeting abstract ruminative processing as an early treatment for depression.