Neuropsychological test performance among major clinical subtypes of depression

Thirty-six patients with diagnoses of major depression were administered the Luria-Nebraska Neuropsychological Battery. Comparisons were made on six dichotomous subtypes of depression: agitated-nonagitated, endogenous-nonendogenous, primary-secondary, psychotic-nonpsychotic, retarded-nonretarded, and unipolar-bipolar. The psychotic depressives were more impaired than the nonpsychotics on the Profile Elevation and Impairment scales. No differences were found for other subtype comparisons on these global measures of neuropsychological dysfunction. Analysis of age effects indicated that older depressives performed more slowly on timed performance items and significant subtype differences on these items occurred for subtype diagnoses of psychotic, primary, and retarded depression. Localization and Lateralization scales revealed significant impairment for the psychotic and retarded patients, with less impairment for other subtypes. The relevance of these findings for neuropsychological evaluation are discussed, particularly with regard to the potentially confounding effects of depression on test performance.