Group and site differences on the California Verbal Learning Test in persons with schizophrenia and their first-degree relatives: findings from the Consortium on the Genetics of Schizophrenia (COGS).

TitleGroup and site differences on the California Verbal Learning Test in persons with schizophrenia and their first-degree relatives: findings from the Consortium on the Genetics of Schizophrenia (COGS).
Publication TypeJournal Article
Year of Publication2011
AuthorsStone, WS, Giuliano AJ, Tsuang MT, Braff DL, Cadenhead KS, Calkins ME, Dobie DJ, Faraone SV, Freedman R, Green MF, Greenwood TA, Gur RE, Gur RC, Light GA, Mintz J, Nuechterlein KH, Olincy A, Radant AD, Roe AH, Schork NJ, Siever LJ, Silverman JM, Swerdlow NR, Thomas AR, Tsuang DW, Turetsky BI, Seidman LJ
JournalSchizophrenia research
Volume128
Issue1-3
Pagination102-10
Date Published2011 May
ISSN1573-2509
KeywordsAdult, Analysis of Variance, Endophenotypes, Female, Humans, Learning Disorders, Male, Mental Recall, Middle Aged, Neuropsychological Tests, Psychiatric Status Rating Scales, Psychometrics, Schizophrenia, Siblings, Verbal Learning, Young Adult
Abstract

Genetic studies of schizophrenia focus increasingly on putative endophenotypes because their genetic etiology may be simpler than clinical diagnosis. The Consortium on the Genetics of Schizophrenia (COGS), a multisite family study, aims to identify the genetic basis of several endophenotypes including verbal declarative memory (VDM), a neurocognitive function that shows robust impairment in schizophrenia. We present data on one type of measure of VDM, the California Verbal Learning Test, Second Edition (CVLT-II), in schizophrenia probands (n=305), their full biological siblings (n=449) and parents (n=232), and in community comparison subjects (CCS; n=509) across seven sites. Probands performed more poorly on each of five CVLT-II measures compared to related sibling and parent groups and CCS. Siblings and parents performed significantly worse than CCS on one measure (Discriminability), but with smaller effect sizes and less impairment than observed previously. The results raise questions about the homogeneity of VDM as an endophenotype, about methodological issues related to sampling, and about psychometric issues that impact the utility of the CVLT for detecting VDM deficits in nonpsychotic relatives of persons with schizophrenia.

DOI10.1111/j.1399-5618.2012.00989.x
Alternate JournalSchizophr. Res.