Verbal memory impairment in healthy siblings of patients with schizophrenia

Abstract

Cognitive deficits have been recognized as a core feature of schizophrenia (SZ) and are present in most patients. Verbal memory (VM), working memory (WM), and executive function (EF) are domains commonly impaired in patients with SZ. These latter domains have been related to the genetic risk of the disorder characterizing as possible endophenotypes. In order to study neurocognitive endophenotypes in a Brazilian population with elevated genetic risks to develop SZ, we measured VM (Hopkins Verbal Learning Test Revised), WM (Letter-Number Sequencing and Digit Span) and EF (Stroop Test) in 90 subjects (45 unaffected siblings of patients with SZ and 45 matched healthy controls). No differences were found in EF and WM (Letter-Number Sequencing and Digit Span). However, in VM, siblings of patients performed worse than controls on the immediate recall and delayed recall. Our results suggest that VM impairment could be considered an endophenotype of SZ.

Keywords: Endophenotypes; Executive function; Schizophrenia; Verbal memory; Working memory.