Nicola L. Barclay

I am interested in investigating the factors accounting for the individual variation in sleep quality observed in the general population. Using quantitative genetic techniques, my research investigates i) the magnitude to which genetic and environmental factors influence sleep quality and associated phenotypes (such as diurnal preference/ circadian rhythmicity); ii) specific social determinants of sleep quality; and iii) the possibility of statistical gene-environment interaction (GxE). Using molecular genetic techniques, I am interested in identifying specific genetic polymorphisms associated with sleep disturbance and indices of circadian rhythmicity, and investigating measured GxE in the onset of sleep problems.

Much of my research to date focusses on data from the G1219 study - a longitudinal population based twin registry in the UK. G1219 twins and siblings have provided data on numerous phenotypes, including anxiety, depression, life events, friendships, relationships and sleep, amongst other things. This has allowed me to explore the possible associations between a host of environmental factors and sleep. Recently, DNA has been obtained from the study participants, allowing us to investigate genetic polymorphisms associated with behaviour, as well as measured GxE.

My research is conducted in collaboration with researchers from numerous institutions, including Goldsmiths (UK); The Institute of Psychiatry (UK); the University of Surrey (UK); the University of Sheffield (UK); the University of Pittsburgh (USA); and the University of Washington (USA).

Publications

Barclay, N.L. (in press). Sleep quality: A behavioural genetic perspective. Encyclopedia of Sleep and Dreams. [Invited Article]

Zavos, H.M.S., Barclay, N.L., Wong, C.C.Y., Keers, R., Mill, J., Gregory, A.M., Eley, T.C. (in press). Gene-environment interplay in association between anxiety sensitivity and later anxiety. British Journal of Psychiatry.

Barclay, N. L., Gregory, A. M. (in press). Quantitative genetic research on sleep: a review of normal sleep, sleep disturbances and associated emotional, behavioural and health-related difficulties. Sleep Medicine Reviews.

Barclay, N. L., Gregory, A. M. (under review). Sleep and Psychopathology: Quantitative and Molecular Genetic Research on Comorbidity. Behavior Genetic Series.

Barclay, N.L., Eley, T.C., Buysse, D.J., Maughan, B., Gregory, A.M. (2012). Nonshared environmental influences on sleep quality: A study of monozygotic twin differences. Behavior Genetics, 42, 234-244.

Gregory, A. M., Buysse, D. J, Willis, T.A., Rijsdijk, F. V., Maughan, B., Rowe, R., Cartwright, S., Barclay, N.L., Eley, T.C. (2011). Associations between sleep quality and anxiety and depression symptoms in a sample of young adult twins and siblings. Journal of Psychosomatic Research, 71, 250-255.

Barclay, N.L., Eley, T.C., Mill, J., Wong, C.C.Y., Zavos, H.M., Archer, S.N., Gregory, A.M. (2011). Sleep quality and diurnal preference in a sample of young adults: Associations with 5HTTLPR, PER3 and CLOCK 3111. American Journal of Medical Genetics: Part B: Neuropsychiatric Genetics. 156, 681–690.

Barclay, N.L., Eley, T.C., Rijsdijk, F.V., Gregory, A.M. (2011). Dependent negative life events and sleep quality: An examination of gene-environment interplay. Sleep Medicine, 12, 403-409.

Barclay, N.L., Eley, T.C., Maughan, B., Rowe, R., Gregory, A.M. (2011). Associations between diurnal preference, sleep quality and externalising behaviours: A behavioural genetic analysis. Psychological Medicine, 41, 1029-1040.

Barclay, N.L., Eley, T.C., Buysse, D. J., Rijsdijk, F. V., Gregory, A.M. (2010). Genetic and environmental influences on different components of the Pittsburgh Sleep Quality index and their overlap. Sleep, 33, 659-668.

Barclay, N.L., Eley, T.C., Buysse, D. J., Archer, S.N., Gregory, A.M. (2010). Diurnal preference and sleep quality: same genes? A study of young adult twins. Chronobiology International, 27, 278-296.

Barclay, N.L., Gregory, A.M. (2010). The presence of a perseverative iterative style in poor vs. good sleepers. Journal of Behavior Therapy and Experimental Psychiatry, 41, 18-23.

Gregory, A.M., Barclay, N.L. (2009). Too stressed to sleep. Psychologist. [Invited Article].