Evaluating cognitive impairment in depression with the Luria-Nebraska Neuropsychological Battery: severity correlates and comparisons with nonpsychiatric controls.

Depressed patients often complain of memory and attentional difficulties, and some research suggests an increased incidence of neuropsychological impairment in depression. Yet, many prior studies contain methodological problems, including the following: (1) inclusion of medicated patients, (2) small sample sizes, and (3) tests with unknown psychometric properties. We administered the Luria-Nebraska Neuropsychological Battery (LNNB) to 28 unmedicated inpatients who met Research Diagnostic Criteria for major depression. Twenty of the 28 patients were given additional cognitive measures (e.g., Wechsler Adult Intelligence Scale-Revised, Benton Tests). The depressed patients performed similarly to an age- and education-matched nonpsychiatric reference sample. When data for a subset of the most severely depressed patients were analyzed separately, these patients too were found to perform similarly to matched controls. There were no relationships between Hamilton rating scale measures of depression severity and any cognitive measures among the depressed patients. The results suggest that cognitive functioning in depressed patients does not differ significantly from that in carefully matched controls and is independent of symptom severity.