Verbal recall and recognition in twins discordant for schizophrenia.

TitleVerbal recall and recognition in twins discordant for schizophrenia.
Publication TypeJournal Article
Year of Publication2008
Authorsvan Erp, TGM, Therman S, Pirkola T, Tuulio-Henriksson A, Glahn DC, Bachman P, Huttunen MO, Lönnqvist J, Hietanen M, Kaprio J, Koskenvuo M, Cannon TD
JournalPsychiatry research
Date Published2008 Jun 30
KeywordsAdult, Control Groups, Diseases in Twins, Female, Finland, Hippocampus, Humans, Language Tests, Male, Memory Disorders, Mental Recall, Phenotype, Psychiatric Status Rating Scales, Psychotic Disorders, Recognition (Psychology), Schizophrenia, Schizophrenic Psychology, Twins, Dizygotic, Twins, Monozygotic, Verbal Learning

The nature, neural underpinnings, and etiology of deficits in verbal declarative memory in patients with schizophrenia remain unclear. To examine the contributions of genes and environment to verbal recall and recognition performance in this disorder, the California Verbal Learning Test was administered to a large population-based Finnish twin sample, which included schizophrenic and schizoaffective patients, their non-ill monozygotic (MZ) and dizygotic (DZ) co-twins, and healthy control twins. Compared with controls, patients and their co-twins showed relatively greater performance deficits on free recall compared with recognition. Intra-pair differences between patients and their non-ill co-twins in hippocampal volume and memory performance were highly positively correlated. These findings are consistent with the view that genetic influences are associated with reduced verbal recall in schizophrenia, but that non-genetic influences further compromise these abnormalities in patients who manifest the full-blown schizophrenia phenotype, with this additional degree of disease-related declarative memory deficit mediated in part by hippocampal pathology.

Alternate JournalPsychiatry Res