title: Sleep quality varies as a function of 5-HTTLPR genotype and stress.
abstract: OBJECTIVE
  To test the hypothesis that allelic variation in 5HTT gene-linked polymorphic region (5-HTTLPR) genotype was associated with sleep quality (Pittsburgh Sleep Quality Index, PSQI) as a main effect and as moderated by the chronic stress of caregiving. Serotonin (5HT) is involved in sleep regulation and the 5HT transporter (5HTT) regulates 5HT function. A common 44-base pair deletion (s allele) polymorphism in the 5-HTTLPR is associated with reduced 5HTT transcription efficiency and 5HT uptake in vitro.
  
  
  METHODS
  Subjects were 142 adult primary caregivers for a spouse or parent with dementia and 146 noncaregiver controls. Subjects underwent genotyping and completed the PSQI.
  
  
  RESULTS
  Variation in 5-HTTLPR genotype was not related to sleep quality as a main effect (p > .36). However, there was a caregiver X 5-HTTLPR interaction (p < .009), such that the s allele was associated with poorer sleep quality in caregivers as compared with controls.
  
  
  CONCLUSIONS
  Findings suggest that the s allele may moderate sleep disturbance in response to chronic stress.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. brummett@duke.edu
authors.forename: Beverly H
authors.initials: BH
authors.lastname: Brummett
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krystal
authors.forename: Allison
authors.initials: A
authors.lastname: Ashley-Koch
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Kuhn
authors.forename: Stephan
authors.initials: S
authors.lastname: Züchner
authors.forename: Ilene C
authors.initials: IC
authors.lastname: Siegler
authors.forename: John C
authors.initials: JC
authors.lastname: Barefoot
authors.forename: Edna L
authors.initials: EL
authors.lastname: Ballard
authors.forename: Lisa P
authors.initials: LP
authors.lastname: Gwyther
authors.forename: Redford B
authors.initials: RB
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D017028:Caregivers / Q000523:psychology; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000235:genetics* / Q000523:psychology*; D013315:Stress, Psychological
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin