Association of subclinical psychosis with suicidal ideation: A twin study

Kirstie J M O'Hare, Tellervo Korhonen, Antti Latvala, Jaakko Kaprio, Richard J Linscott

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Subclinical psychosis, including schizotypal indicators and psychotic experiences, predicts future suicidal ideation. This relationship may reflect unmeasured confounding from environmental factors, genetic factors, or both. We used a genetically-informative twin design to understand if the association between subclinical psychosis and suicidal ideation is independent of shared genetic and environmental factors. We analysed cross-sectional associations of age-22 self-reported subclinical psychosis (positive, negative, and disorganised features) with suicidal ideation in twins participating in the FinnTwin12 study (maximum n = 1213). Then, we analysed the reverse association of age-14 suicidal ideation with age-22 subclinical psychosis. Associations were studied first among individuals and then within monozygotic (MZ) and dizygotic (DZ) pairs. Individual-level analyses showed that all subclinical psychosis factors were associated with suicidal ideation. In within-pair analyses, estimates of associations were lower for MZ pairs than DZ pairs, except for the negative schizotypy-suicidal ideation association where estimates were consistent across individual-level and within-pair analyses. Findings provide evidence that the association between negative features and suicide ideation is not explained by familial factors and may be causal, though the possibility of confounding by individual-specific environmental factors and reverse causation cannot be ruled out. The relationships of positive and disorganised subclinical psychosis features with suicidal ideation cannot be explained by confounding due to environmental factors shared between siblings, but their associations may be due to shared genetic factors.

Original languageEnglish
Pages (from-to)173-178
Number of pages6
JournalSchizophrenia Research
Early online date28 Jul 2020
Publication statusPublished - Sept 2020

Keywords / Materials (for Non-textual outputs)

  • Adolescent
  • Adult
  • Cross-Sectional Studies
  • Humans
  • Psychotic Disorders/epidemiology
  • Risk Factors
  • Suicidal Ideation
  • Twins, Monozygotic
  • Young Adult

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