The Comparison of the Neurocognitive Functions between Dysthymic Disorder and Major Depressive Disorder

ABSTRACT

Neurocognitive research focusing on cognitive deficits in Depression has resulted in several important but yet potentially contradictory findings. Much literature documents the presence of significant neurocognitive impairments in depressive patients. Studies have shown that dysthymic disorder patients demonstrate a diffuse pattern of cognitive impairment which is frequently indistinguishable from that of focal braindamaged patients. Some reports have suggested that there is a focal pattern of deficit, such as anterior cingulate dysfunction, frontal lobe impairment, or dysfunction of the temporal-limbic cortex. The aim of this study is to evaluate the neurocognitive functions in dysthymic disorder patients, and to compare the functions with those of major depressive disorder patients. The subjects are 17 dysthymic disorder patients. And their neurocognitive functions are compared with those of 23 major depressive episode patients. Patients with a history of neurologic disease, alcohol dependence, substance abuse and mental retardation are excluded. They are assessed with a part of Vienna Test System which is computerized neurocognitive function tests and can evaluate attention, eductive ability, reproductive ability, visuoperceptual analysis, vigilance, visual immediate memory, the speed of information-processing, judgement, and fine motor coordinations. There are no other specific difference between two groups, except the result of cognitrone test. This study provides information about the neurocognitive functions and some difference between major depressive disorder patients and carefully diagnosed dysthymic disorder patients.