Testing the Validity of Taxonic Schizotypy Using Genetic and Environmental Risk Variables

Sarah E. Morton, Kirstie J. M. O'Hare, Jaimee L. K. Maha, Max P. Nicolson, Liana Machado, Ruth Topless, Tony R. Merriman, Richard J. Linscott*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Web of Science)

Abstract

Background: Meehl regarded schizotypy as a categorial liability for schizophrenia that is the product of genes, environment, and gene-environment interactions. We sought to test whether schizophrenia-related genotypes and environmental risk factors predict membership in classes defined by taxometric analyses of positive (cognitive-perceptual), negative (interpersonal), and disorganized schizotypy. Methods: Participants (n = 500) completed the Schizotypal Personality Questionnaire (SPQ) and provided information on the following risk factors: cannabis use, pregnancy and obstetric complications, social adjustment, and family history of psychosis. Saliva samples were obtained so that the frequency of single-nucleotide polymorphism (SNP) alleles associated with risk for developing schizophrenia could be determined. Genotyped SNPs were rs1625579 (MIR137), rs7004633 (MMP16), rs7914558 (CNNM2), and rs12966547 (CCDC68). Sets of SPQ items were subject to multiple coherent cut kinetic (CCK) analyses, including mean above-minus-below-a-cut, maximum covariance, maximum eigenvalue, and latent modes analyses. Results: CCK analyses indicated latent taxonicity of schizotypy across the 3 item sets. The cognitive-perceptual class had a base rate of 25%, and membership was predicted by the rs7004633 SNP (odds ratio = 2.33, 95% confidence interval = 1.15-4.72 in adjusted analyses). Poor social adjustment predicted memberships in the interpersonal (16%) and disorganized (21%) classes. Classes were found not to be mutually exclusive. Conclusions: Schizotypy is taxonic and schizotypy class membership is predicted by genetic and environmental factors that predict schizophrenia. The findings hold the promise that a more complete understanding of schizotypy as a schizophrenia liability state will come from investigation of other genes and environmental factors associated with schizophrenia.

Original languageEnglish
Pages (from-to)633-643
Number of pages11
JournalSchizophrenia Bulletin
Volume43
Issue number3
DOIs
Publication statusPublished - 1 May 2017

Keywords

  • schizophrenia
  • maximum covariance analysis
  • psychosis
  • class structure
  • taxometrics
  • MMP16
  • social adjustment
  • SCHIZOPHRENIA-SPECTRUM DISORDERS
  • LATENT STRUCTURE
  • TAXOMETRIC ANALYSIS
  • OBSTETRIC COMPLICATIONS
  • BIPOLAR DISORDER
  • MAXCOV PROCEDURE
  • FAMILY-HISTORY
  • CANNABIS USE
  • PSYCHOSIS
  • PERSONALITY

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