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.
Original language | English |
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Pages (from-to) | 102-110 |
Number of pages | 9 |
Journal | Schizophrenia Research |
Volume | 128 |
Issue number | 1-3 |
DOIs | |
State | Published - May 2011 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the NIMH through grants to Harvard University (RO1-MH065562), Mount Sinai School of Medicine (ROI-MH065554), University of California Los Angeles (RO1-MH65707), University of California San Diego (RO1-MH065571), University of Colorado (RO1-MH65588), University of Pennsylvania (RO1-MH65578) and the University of Washington (RO1-MH65558).
Keywords
- Endophenotype
- Schizophrenia
- Verbal declarative memory