Prospects for epigenetic research within cohort studies of psychological disorder: A pilot investigation of a peripheral cell marker of epigenetic risk for depression

• Published in: Biological psychology Vol. 83; no. 2; pp. 159 - 165
• Main Authors: Olsson, C.A., Foley, D.L., Parkinson-Bates, M., Byrnes, G., McKenzie, M., Patton, G.C., Morley, R., Anney, R.J.L., Craig, J.M., Saffery, R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2010; Elsevier
• Subjects: Adolescent; Adult and adolescent clinical studies; Behavioral psychophysiology; Biological and medical sciences; Biomarkers; Cohort Studies; Depression; Depressive Disorder - diagnosis; Depressive Disorder - genetics; Depressive Disorder - psychology; DNA methylation; Epigenesis, Genetic; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Methylation; Mood disorders; Pilot Projects; Polymorphism genetic; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopathology. Psychiatry; Risk Factors; Serotonin Plasma Membrane Transport Proteins - genetics; Severity of Illness Index; Young Adult; DNA methylation; Depression; Polymorphism genetic; Adolescent; Cohort studies; Human; Mood disorder; Genetic determinism; Serotonin transporter; DNA; Cohort study; Risk factor; Genetics; Epigenesis; Psychopathology; Methylation; Polymorphism
• ISSN: 0301-0511; 1873-6246
• DOI: 10.1016/j.biopsycho.2009.12.003

Cohort studies have considerable
prima facie value for investigating epigenetic processes in psychological disorder; however, the future prospects for such studies will depend on valid peripheral markers. The purpose of this pilot study was to investigate association between buccal cell methylation and risk for depression. Epigenotyping was limited to promoter methylation of the serotonin transporter gene (
5HTT)
. A transcription limiting VNTR in the
5HTT promoter (
5HTTLPR) was also genotyped. A nested sample of 25 depressed and 125 non-depressed adolescents was drawn from an established longitudinal study of adolescent health. There was no association between depressive symptoms and either buccal cell
5HTT methylation or
5HTTLPR. However, depressive symptoms were more common among those with elevated buccal cell
5HTT methylation who carried
5HTTLPR short-allele (OR 4.9, CI 1.9–13,
p
=
0.001). Both complete and partial (as little as 10%) methylation of a 5HTT reporter gene in an expressing cell line reduced
5HTT activity. Replication is needed.