Abnormal response to failure in unmedicated major depression

An aspect of neuropsychological impairment which has been linked specifically to depression is an abnormal response to failure. That is, a rapid deterioration of performance after receiving feedback that an error was made on the previous task. We aimed to examine this phenomenon in unmedicated, depressed outpatients.

Forty-four patients meeting DSM-IV criteria for major depression, all psychotropicmedication-free for at least six weeks, and 44 demographically matched, healthy control participants completed a computerised simultaneous/delayed matching-to-sample task (S/DMTS).

Patients with depression were significantly less accurate than controls on the S/DMTS task. Both groups augmented their performance after an error had been made. The probability of making an error following an error was significantly greater in depressed compared with control participants, even when total number of errors was controlled for. Response latencies reduced significantly after an error had been made for both groups.

Both groups made relatively few errors. This reduced the power of analysis particularly when examining the effect of delay.

The abnormal response to negative feedback previously identified in depressed samples was replicated in the current unmedicated, less severely depressed group. The impairment shown in the depressed sample may be due to a reduction in the motivating effect of an error compared with healthy controls. This has possible relevance to both neurobiological and psychological theories of depression.