Major Depressive Disorder and Emotion-Related Impulsivity: Are Both Related to Cognitive Inhibition?

Previous studies indicate that emotion-relevant impulsivity is related to depression and relatedly, suicidal ideation and behavior. Little is known, however, about underlying mechanisms driving this impulsivity. We hypothesized that participants diagnosed with depression would show difficulties with emotion-related impulsivity and inhibition compared to controls, and that there would be a link between inhibition deficits and emotion-relevant impulsivity. To test these hypotheses, 60 participants diagnosed with lifetime major depressive disorder (MDD; 47 full-remission, 8 current MDD, 5 partial remission) and 100 nondepressed controls completed measures of impulsivity and current depressive symptoms, underwent a negative mood induction, and completed tasks that assessed components of inhibition: the ability to suppress pre-potent responses (antisaccade task) and the ability to resist interference (word-naming task). Although people with a history of MDD did not show cognitive inhibition deficits, they did endorse more emotion-related impulsivity, which in turn related to difficulty suppressing pre-potent responses. Limitations, as well as implications for future research and treatment are discussed.