The heritability of melatonin secretion and sensitivity to bright nocturnal light in twins.

Full text for this resource is not available from the Research Repository.

Hallam, Karen, Olver, J. S, Chambers, V, Begg, Denovan P, McGrath, Caroline and Norman, T. R (2006) The heritability of melatonin secretion and sensitivity to bright nocturnal light in twins. Psychoneuroendocrinology, 31 (7). pp. 867-875. ISSN 0306-4530


The super-sensitivity of the neurohormone melatonin to light in patients with bipolar disorder provides evidence of the circadian nature of the disorder. This response has been proposed as an endophenotype for identifying people at risk of the disorder and guiding investigations of molecular genetic targets. However, before this response is used as an endophenotypic marker, the heritable nature of melatonin sensitivity in the normal population must be established. The aim of this study was to investigate the heritability of nocturnal melatonin secretion and sensitivity to light in monozygotic and dizygotic twins with no psychiatric history. This study investigated overall melatonin levels (between 2000 and 2400 h) and suppression by 500 lx of light (between 2400 and 0100 h) in 20 pairs of twins (nine monozygotic, 11 dizygotic). The results indicate that melatonin secretion is highly heritable with secretion in one twin being a significant predictor of secretion in their twin in both monozygotic and dizygotic pairs. In relation to light sensitivity, genetic loading appears to play a significant role with the greatest concordance between monozygotic twins, followed by dizygotic twins and finally low concordance in unrelated individuals. This provides additional support for the usefulness of melatonin sensitivity to light as a potential endophenotypic marker of bipolar affective disorder.

Item type Article
Subjects Historical > Faculty/School/Research Centre/Department > School of Social Sciences and Psychology
Historical > FOR Classification > 1109 Neurosciences
Keywords ResPubID16570, melatonin, light sensitivity, endophenotype, bipolar affective disorder, twin study, heritability
Citations in Scopus 73 - View on Scopus
Download/View statistics View download statistics for this item

Search Google Scholar

Repository staff login