Navigation Links
Gene Mutation May Cause Some Cases of Seasonal Affective Disorder
Date:11/7/2008

Finding could help identify people who'd respond to light therapy, study says

FRIDAY, Nov. 7 (HealthDay News) -- A mutated gene in the eye may account for some cases of seasonal affective disorder, that annual bout of "winter blues" experienced by an estimated 6 percent of the U.S. population as the days get shorter.

"SAD [seasonal affective disorder] is a kind of major depression that recurs every year right around the fall," said lead researcher Ignacio Provencio, an associate professor of biology at the University of Virginia. "By the spring and early summer, it goes away."

Provencio noted that the treatment for SAD is light therapy, which usually takes about two hours a day. "Exposing patients to bright light can actually get rid of some of these symptoms and allow patients to function normally during the winter," he said.

Since light is the treatment for SAD, Provencio's group speculated that people with the condition may be less sensitive to light. "They can overcome that insensitivity by increasing the amount of light they're exposed to," he noted.

But only 50 percent of SAD patients respond to light therapy, Provencio said. "So it could be that this mutation could allow a way of predicting patients that may be responsive to light therapy," he added.

For the study, published in the November online edition of the Journal of Affective Disorders, Provencio's team looked at genes in 220 people. One hundred thirty of the people had been diagnosed with SAD, and 90 had no history of SAD or any other depressive disorder.

The researchers found that seven people had two copies of the mutated gene thought to be involved in SAD. All seven were in the group that had been diagnosed with the depressive condition. The researchers concluded that someone with two copies of the mutation was five times more likely to develop SAD, compared with someone without the mutation, Provencio said.

The gene is called the melanopsin gene, and it produces a light-sensitive protein found in photoreceptors in the eye's retina. The protein is not involved with vision, but it is linked to non-visual responses, such as circadian rhythms, hormones, alertness and sleep, Provencio said.

A mutation of the melanopsin gene may cause a change in responses to light, which can lead to symptoms of depression. Among SAD patients, about 29 percent have a family history of the condition, suggesting there may be a genetic component, according to background information in the study.

"Not all people with SAD have this mutation," Provencio said. "But, at least in our study, all the people who had two mutated copies of this gene were in the SAD group. We think we may have found a cause of SAD among a subset of patients."

Dr. Daniel F. Kripke, a professor of psychiatry emeritus at the University of California, San Diego, called the finding interesting, but said it only accounts for a small number of SAD cases.

"This is a responsible piece of work," Kripke said. "The finding is promising, but it needs to be repeated and may not be correct. If it is correct, it appears to explain only about 5 percent of the cause of SAD."

More information

To learn more about SAD, visit the U.S. National Library of Medicine.



SOURCES: Ignacio Provencio, Ph.D., associate professor, biology, University of Virginia, Charlottesville; Daniel F. Kripke, M.D., professor emeritus, psychiatry, University of California, San Diego; November 2008 Journal of Affective Disorders, online


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Risk of breast cancer mutations underestimated for Asian women, Stanford study shows
2. Genetic Mutations Linked to Deadly Cancers
3. Inherited form of hearing loss stems from gene mutation
4. Gene Mutation Puts Some Kids at Risk for Tobacco Addiction
5. Common Mechanisms May Contribute to Autisms Mutations
6. Gene Mutation Tied to Inherited Atrial Fibrillation
7. Migraine mutations reveal clues to biological basis of disorder
8. Caris Diagnostics Providing KRAS Mutational Analysis for Colon Cancer Patients
9. New research on mutation in yeast can enhance understanding of human diseases
10. Gene mutation improves leukemia drugs effect
11. Specific mutations in the IL2RA gene associated with juvenile idiopathic arthritis
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... ... June 27, 2016 , ... TherapySites, ... today its affiliation with Tennessee Counseling Association. This new relationship allows ... the Tennessee Counseling Association, adding exclusive benefits and promotional offers. , "TCA is ...
(Date:6/26/2016)... ... June 26, 2016 , ... On June 10-11, 2016, A Forever Recovery, a ... and World’s Longest Breakfast Table in Battle Creek, MI, where the rehabilitation facility is ... to some of the world’s leading providers of cereal and other breakfast foods. Its ...
(Date:6/25/2016)... ... 25, 2016 , ... Experts from the American Institutes for ... Meeting June 26-28, 2016, at the Hynes Convention Center in Boston. , AIR ... care planning, healthcare costs and patient and family engagement. , AIR researchers will ...
(Date:6/25/2016)... ... ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his Bachelors in ... School of Medicine at UCLA. He trained in Internal Medicine at Scripps Green Hospital ... at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to train in ...
(Date:6/24/2016)... ... June 24, 2016 , ... Those who have experienced traumatic events may suffer ... unhealthy avenues, such as drug or alcohol abuse, as a coping mechanism. To avoid ... healthy coping following a traumatic event. , Trauma sufferers tend to feel a range ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 2016  In a startling report released today, National Safety ... lacking a comprehensive, proven plan to eliminate prescription opioid overdoses. ... how states are tackling the worst drug crisis in recorded U.S. ... Kentucky , New Mexico , ... Of the 28 failing states, three – Michigan ...
(Date:6/23/2016)... DUBLIN , June 23, 2016 ... "Global MEMS Devices Medical Market Analysis 2016 - Forecast to ... The report contains up to date financial ... reliable analysis. Assessment of major trends with potential impact on ... dive analysis of market segmentation which comprises of sub markets, ...
(Date:6/23/2016)... Research and Markets has announced the addition of the ... offering. The current unmet ... for MedImmune to enter. The US ageing population creates a ... considerable growth for effective anti-influenza medications. The introduction of a ... development is still in its infancy. Key ...
Breaking Medicine Technology: