Set shifting deficits in melancholic vs. non-melancholic depression: preliminary findings.

Twenty-two patients with major depressive disorder, 11 of them with melancholic features, and 11 controls were investigated with CANTAB subtests focusing in visual memory/learning and executive functions. Melancholic patients performed worse than the other groups in all tasks and manifested a significant impairment in set shifting. The results are discussed in association with prefrontal dysfunction.