Revealing negative thinking in recovered major depression: a preliminary investigation

Previous research suggests that formerly dysphoric individuals engage in effortful strategies (e.g., thought suppression) that may mask underlying depressive thinking. The addition of a cognitive load, such as recalling a 6-digit number, which interferes with effortful mental control, reveals depressive thinking in formerly dysphoric individuals. This preliminary study tested whether this effect of cognitive load on revealing negative thinking generalizes to formerly clinically depressed patients. Currently depressed patients, recovered depressed patients and never-depressed patients unscrambled sentences that could form either positive or negative statements, after random allocation to either cognitive load or no cognitive load conditions. The number of negative statements unscrambled was used as an index of negative thinking. Without a load, recovered depressed patients did not differ from never-depressed controls: both groups completed fewer negative statements than currently depressed patients. However, the cognitive load increased negative statements in the recovered depressed group, making them resemble the currently depressed group more than the never-depressed group. These preliminary findings extend previous demonstrations of cognitive load unmasking negative thinking in dysphoric students to a clinical population, suggesting that formerly depressed patients utilize effortful strategies to minimize the report of negative thinking, which is undermined by the addition of a cognitive load.