Emotion modulates cognitive flexibility in patients with major depression.

BACKGROUND: Depression is associated with alterations of emotional and cognitive processing, and executive control in particular. Previous research has shown that depressed patients are impaired in their ability to shift attention from one emotional category to another, but whether this shifting deficit is more evident on emotional relative to non-emotional cognitive control tasks remains unclear.
METHOD: The performance of patients with major depressive disorder and matched healthy control participants was compared on neutral and emotional variants of a dynamic cognitive control task that requires participants to shift attention and response from one category to another.
RESULTS: Relative to controls, depressed patients were impaired on both tasks, particularly in terms of performance accuracy. In the neutral go/no-go task, the ability of depressed patients to flexibly shift attention and response from one class of neutral stimuli to the other was unimpaired. This contrasted with findings for the emotional go/no-go task, where responding was slower specifically on blocks of trials that required participants to shift attention and response from one emotional category to the other.
CONCLUSIONS: The present data indicate that any depression-related difficulties with cognitive flexibility and control may be particularly evident on matched tasks that require processing of relevant emotional, rather than simply neutral, stimuli. The implications of these findings for our developing understanding of cognitive and emotional control processes in depression are discussed.