Melanopsin Polymorphisms in Seasonal Affective Disorder
Abstract
Seasonal affective disorder (SAD) is characterized by winter depressive episodes and springtime remission. SAD may result from a genetically mediated abnormal response to low light availability during winter. One candidate gene for SAD is melanopsin, a non-visual, circadian photopigment. The present study determined the frequency of a genetic polymorphism in melanopsin (P10L) in individuals with SAD (n=36) compared to two groups: gender-matched controls with no history of depression and minimal seasonality (n=22), and a larger comparison group of samples obtained from NIH that have been delinked from identifying information (n=84). The proportion of SAD participants with P10L (28%) did not differ significantly from the comparison group (15%) or nondepressed controls (18%). A post-hoc power analysis revealed that a sample of 200 participants would be required in future studies. If a sufficiently sized sample that includes gender- and ethnicity-matched controls becomes available, then the study should be repeated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA435422
Entities
People
- Kathryn A. Roecklein
Organizations
- Uniformed Services University of the Health Sciences