Executive functioning and verbal memory in young patients with unipolar depression and schizophrenia

Although neuropsychological studies have consistently reported executive de ficits in schizophrenia, studies of executive functions in depression have produced equivocal results. The aim of this study was to examine the profil e and the specificity of the executive impairment and its association with memory performance in young patients with unipolar depression. We compared patients with depression to normal control subjects and schizophrenics. Twe nty young inpatients with unipolar depression, 14 schizophrenics and 20 age -, education- and IQ-matched control subjects were assessed with a neuropsy chological battery including: (1) verbal memory task; (2) frontal tasks (WC ST, Cognitive Estimate, Verbal fluency, verbal and visuo-spatial span) and a new complex sorting test (Delis test). Depressed patients and schizophren ics exhibited executive deficits. Unlike schizophrenics, depressed patients did not show memory impairment. Deficits in several 'higher-level' functio ns combined to produce executive impairments in patients with depression in cluding complex integration for concept formation, spontaneous cognitive fl exibility and initiation ability. Impaired functions in schizophrenia and i n depressed patients were similar but were differently related to clinical variables. The pattern of memory failure in our schizophrenics is believed to reflect retrieval and encoding deficits. Our findings highlight the hete rogeneity of skills grouped under the term 'executive functions' that are v ulnerable in depression or schizophrenia. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.