title: 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).
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.
authors.affiliation: Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, MA 02215, USA. wstone@bidmc.harvard.e
authors.forename: William S
authors.initials: WS
authors.lastname: Stone
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Giuliano
authors.forename: Ming T
authors.initials: MT
authors.lastname: Tsuang
authors.forename: David L
authors.initials: DL
authors.lastname: Braff
authors.forename: Kristin S
authors.initials: KS
authors.lastname: Cadenhead
authors.forename: Monica E
authors.initials: ME
authors.lastname: Calkins
authors.forename: Dorcas J
authors.initials: DJ
authors.lastname: Dobie
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Faraone
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authors.lastname: Freedman
authors.forename: Michael F
authors.initials: MF
authors.lastname: Green
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Greenwood
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Gur
authors.forename: Ruben C
authors.initials: RC
authors.lastname: Gur
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Light
authors.forename: Jim
authors.initials: J
authors.lastname: Mintz
authors.forename: Keith H
authors.initials: KH
authors.lastname: Nuechterlein
authors.forename: Ann
authors.initials: A
authors.lastname: Olincy
authors.forename: Allen D
authors.initials: AD
authors.lastname: Radant
authors.forename: Andrea H
authors.initials: AH
authors.lastname: Roe
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Schork
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Siever
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Silverman
authors.forename: Neal R
authors.initials: NR
authors.lastname: Swerdlow
authors.forename: Alison R
authors.initials: AR
authors.lastname: Thomas
authors.forename: Debby W
authors.initials: DW
authors.lastname: Tsuang
authors.forename: Bruce I
authors.initials: BI
authors.lastname: Turetsky
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Seidman
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D058068:Endophenotypes; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000209:etiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012559:Schizophrenia / Q000150:complications* / Q000235:genetics*; D035781:Siblings; D014706:Verbal Learning / Q000502:physiology*; D055815:Young Adult