Abnormal response to negative feedback in depression

Background. Recent studies have suggested that subjects with depression suf fer a diagnosis-specific motivational deficit,. characterized by an abnorma l response to negative feedback that endures beyond clinical recovery. Furt hermore, it has been suggested that negative feedback may motivate non-depr essed controls, but not depressed patients, to improve their performance in neuropsychological tests. Methods. We describe two studies. The first compared performance on the sim ultaneous and delayed match to sample (SDMS) task from the CANTAB neuropsyc hological test battery, in 20 patients with severe depression with 20 with acute schizophrenia, 40 with chronic schizophrenia and 40 healthy controls. The second examined the performance of depressed patients with diurnal var iation in symptoms and cognitive function. Results. All patients groups showed impairments on the simultaneous and del ayed match to sample task compared to controls. Depressed patients did not show an abnormal response to negative feedback. Controls did not show a mot ivational effect of negative feedback. Depressed patients with diurnal vari ation showed no variation in their response to perceived failure. There was no evidence of abnormal response to negative feedback in any patient group using the 'runs test' or of a motivational effect in controls. Conditional probability analysis was not independent of the total number of errors mad e in the SDMS task. Conclusions. Further studies are suggested to examine whether an abnormal r esponse to negative feedback characterizes particular subgroups of patients suffering from depression.