Genetic analysis of activity, brain and behavioral associations in extended families with heavy genetic loading for bipolar disorder

Psychol Med. 2021 Feb;51(3):494-502. doi: 10.1017/S0033291719003416. Epub 2019 Dec 9.

Abstract

Background: Disturbed sleep and activity are prominent features of bipolar disorder type I (BP-I). However, the relationship of sleep and activity characteristics to brain structure and behavior in euthymic BP-I patients and their non-BP-I relatives is unknown. Additionally, underlying genetic relationships between these traits have not been investigated.

Methods: Relationships between sleep and activity phenotypes, assessed using actigraphy, with structural neuroimaging (brain) and cognitive and temperament (behavior) phenotypes were investigated in 558 euthymic individuals from multi-generational pedigrees including at least one member with BP-I. Genetic correlations between actigraphy-brain and actigraphy-behavior associations were assessed, and bivariate linkage analysis was conducted for trait pairs with evidence of shared genetic influences.

Results: More physical activity and longer awake time were significantly associated with increased brain volumes and cortical thickness, better performance on neurocognitive measures of long-term memory and executive function, and less extreme scores on measures of temperament (impulsivity, cyclothymia). These associations did not differ between BP-I patients and their non-BP-I relatives. For nine activity-brain or activity-behavior pairs there was evidence for shared genetic influence (genetic correlations); of these pairs, a suggestive bivariate quantitative trait locus on chromosome 7 for wake duration and verbal working memory was identified.

Conclusions: Our findings indicate that increased physical activity and more adequate sleep are associated with increased brain size, better cognitive function and more stable temperament in BP-I patients and their non-BP-I relatives. Additionally, we found evidence for pleiotropy of several actigraphy-behavior and actigraphy-brain phenotypes, suggesting a shared genetic basis for these traits.

Keywords: Actigraphy; activity; bipolar disorder; brain; cognitive function; sleep.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actigraphy
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bipolar Disorder / genetics*
  • Bipolar Disorder / physiopathology*
  • Bipolar Disorder / psychology*
  • Brain / pathology*
  • Cognition
  • Family
  • Female
  • Humans
  • Inheritance Patterns / genetics
  • Linear Models
  • Male
  • Memory, Short-Term
  • Middle Aged
  • Pedigree
  • Phenotype
  • Sleep*
  • Temperament
  • Young Adult