Genetic and environmental influences on different components of the Pittsburgh Sleep Quality Index and their overlap.
OBJECTIVE
To examine the extent to which genetic and environmental factors influence components of sleep quality; the degree to which these components co-occur; and genetic and environmental influences on this co-occurrence.


METHODS
Twin study.


METHODS
Population based twin registry across the U.K.


METHODS
Four hundred twenty monozygotic twins, 773 dizygotic twins, and 363 siblings (mode age = 20 years; range 18 to 27 years).


METHODS
N/A.


RESULTS
The Pittsburgh Sleep Quality Index (PSQI) assessed 7 components of sleep quality which overlap to varying degrees. Genetic influence on individual components ranged from 0% to 47%. The remaining source of variance was non-shared environment, except for "sleep duration", for which shared environmental influences were important. Phenotypic correlations between components ranged from 0.22 to 0.61. Bivariate analyses indicated substantial overlap between genes influencing phenotypes (10 of 15 correlations were > or = 0.69); and in general, genetic influence accounted for roughly half the association (> 40% in 9 of 15 correlations). Non-shared environmental influences were in general less correlated across variables (11 of 15 were < 0.4), but owing to their greater influence on each variable, still accounted for roughly half of each association (> or = 40% in 12 of 15 correlations).


CONCLUSIONS
Genetic and non-shared environmental factors are most important in explaining individual differences with regards to different components of sleep quality, although shared environment may influence sleep duration. The pattern of overlap in the genetic and environmental influences accounting for the associations between components of sleep quality is consistent with that seen in other areas of developmental psychopathology of general genes and specific non-shared environmental influences.
Barclay
Nicola L
NL
Department of Psychology, Goldsmiths, University of London, London, UK. ps701nh@gold.ac.uk
Eley
Thalia C
TC
Buysse
Daniel J
DJ
Rijsdijk
Fruhling V
FV
Gregory
Alice M
AM
D000293:Adolescent; D000328:Adult; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male; D035781:Siblings; D012890:Sleep / Q000235:genetics*; D012893:Sleep Wake Disorders / Q000235:genetics*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D006113:United Kingdom; D055815:Young Adult
Sleep. 2006 Aug;29(8):1063-7
16944675
Pers Individ Dif. 1999;27(5):853-60
11542386
Chronobiol Int. 2010 Jan;27(2):278-96
20370470
J Sleep Res. 2007 Mar;16(1):12-6
17309758
J Psychosom Res. 1998 Jul;45(1):5-13
9720850
J Am Acad Child Adolesc Psychiatry. 2002 Aug;41(8):964-71
12162632
J Psychosom Res. 2011 Oct;71(4):250-5
21911103
Sleep. 2006 Sep;29(9):1155-73
17040003
Sleep. 1983;6(3):179-85
6684786
Am J Respir Crit Care Med. 2001 Sep 15;164(6):949-52
11587976
Psychosom Med. 2007 Sep-Oct;69(7):621-4
17766685
Twin Res. 2000 Dec;3(4):316-22
11463153
Chronobiol Int. 1999 Jan;16(1):79-91
10023578
Psychiatry Res. 1989 May;28(2):193-213
2748771
Sleep. 2006 Jan;29(1):112-6
16453989
J Am Acad Child Adolesc Psychiatry. 2004 Mar;43(3):298-306
15076263
Sleep. 1990 Aug;13(4):318-35
2267475
Sleep. 1996 Apr;19(3 Suppl):S7-15
8723370
Int Rev Psychiatry. 2003 Feb-May;15(1-2):185-7
12745331
Arch Pediatr Adolesc Med. 2008 Apr;162(4):299-304
18391137
Arch Gen Psychiatry. 1975 Nov;32(11):1371-5
1239251
J Sleep Res. 1998 Dec;7(4):248-53
9844851
Sleep. 1997 Sep;20(9):715-23
9406323
J Fam Psychol. 2007 Mar;21(1):58-66
17371110
Science. 2003 Jul 18;301(5631):386-9
12869766
Am J Med Genet B Neuropsychiatr Genet. 2003 Aug 15;121B(1):35-8
12898572
Psychol Bull. 2009 Jul;135(4):608-37
19586164
Behav Genet. 1989 Jan;19(1):37-49
2712812
Sleep Med. 2008 Sep;9 Suppl 1:S10-7
18929313
J Sleep Res. 1999 Jun;8 Suppl 1:11-3
10389101
Psychiatr Genet. 2001 Jun;11(2):65-70
11525419