Navigation Links
Brain chemical may explain why heavy smokers feel sad after quitting

August 2 (Toronto) Heavy smokers may experience sadness after quitting because early withdrawal leads to an increase in the mood-related brain protein monoamine oxidase A (MAO-A), a new study by the Centre for Addiction and Mental Health (CAMH) has shown. This finding, which was published in the Archives of General Psychiatry, may also explain why heavy smokers are at high risk for clinical depression.

Using an advanced brain imaging method, a team led by Senior Scientist Dr. Jeffrey Meyer discovered that MAO-A levels in the brain regions that control mood rose by 25 per cent eight hours after withdrawal from heavy cigarette smoking. These levels were much higher than in a comparison group of non-smoking study participants. All 48 participants filled out questionnaires, and smokers with high brain MAO-A levels during withdrawal also reported greater feelings of sadness.

"Understanding sadness during cigarette withdrawal is important because this sad mood makes it hard for people to quit, especially in the first few days. Also, heavy cigarette smoking is strongly associated with clinical depression," said Dr. Meyer, who holds a Canada Research Chair in the Neurochemistry of Major Depression. "This is the first time MAO-A, a brain protein known to be elevated in clinical depression has been studied during cigarette withdrawal."

MAO-A "eats up" chemicals in the brain, such as serotonin, that help maintain a normal mood. When MAO-A levels are higher as in early cigarette withdrawal, it means that this removal process is overly active, making people feel sad. For this study, MAO-A was detected using a brain imaging technique called positron emission tomography (PET). CAMH has the only PET scanner in the world dedicated solely to mental health and addiction research.

A specific substance in cigarette smoke, called harman, may be responsible for these changes, the researchers note. During active smoking, harman attaches to MAO-A. During early withdrawal in heavy smokers who had 25 or more cigarettes a day, MAO-A levels rose rapidly to a level beyond that seen in the healthy comparison group.

"This study opens new ways to prevent sad mood during cigarette withdrawal to make it easier to quit smoking. For example, it may be possible to improve the existing cigarette filters that partially screen out harman, or regulate the amount of tryptophan contained in cigarettes, since tryptophan becomes harman when it burns," said Dr. Meyer, who is also head of the Neurochemical Imaging Program in Mood Disorders at CAMH's Research Imaging Centre, and professor of psychiatry at the University of Toronto. "We also identified MAO-A as a target to shut down during the early critical stage of withdrawal with a short course of medication, but this requires further study."

"This finding may explain why heavy smokers are at high risk for clinical depression," says Dr. Anthony Phillips, Scientific Director of the Canadian Institutes of Health Research's (CIHR's) Institute of Neurosciences, Mental Health and Addiction, which funded this study.


Contact: Michael Torres
Centre for Addiction and Mental Health

Related medicine news :

1. Smoking, Diabetes, Obesity May Shrink Your Brain
2. New CMU brain imaging research reveals why autistic individuals confuse pronouns
3. Concussion Project Finds Disease in Two Autopsied Brains
4. Brain Injury Appears to Boost Stroke Risk
5. The brains connectome -- from branch to branch
6. Children and adolescent mobile phone users at no greater risk of brain cancer than non-users
7. New imaging technique captures brain activity in patients with chronic low back pain
8. Researchers aim for direct brain control of prosthetic arms
9. Eliminating protein in specific brain cells blocks nicotine reward
10. Fatty Comfort Foods May Alter Brains Response to Sadness
11. Brain autopsies of 4 former football players reveal not all get chronic traumatic encephalopathy
Post Your Comments:
(Date:11/25/2015)... ... November 25, 2015 , ... Medical Solutions, ... again for its stellar workplace culture with the company’s Cincinnati office being named ... Solutions’ Cincinnati office was named a finalist in Cincinnati Business Courier’s 13th annual ...
(Date:11/25/2015)... Friendswood, TX (PRWEB) , ... November 25, 2015 , ... ... through the companies’ “ Two Organizations, One Beat ” campaign. The partnership between the ... its services to aid in MAP International’s cause. , MAP International was founded in ...
(Date:11/25/2015)... Boca Raton, Florida (PRWEB) , ... November 25, ... ... on-site diagnostic testing for physicians and athletic programs, launches new Wimbledon Athletics ... the importance of testing young athletes for unsuspected cardiac abnormalities. About 2,000 people ...
(Date:11/25/2015)... ... November 25, 2015 , ... Beddit® has launched a new Android ... The new app features a more intuitive SleepScore™ that rates sleep quality on a ... The SleepScore is created by a proprietary algorithm. Beddit analyzes the data to provide ...
(Date:11/25/2015)... LOUIS, Missouri (PRWEB) , ... November 25, 2015 ... ... Project HEAL, will provide scholarships for people struggling with eating disorders as a ... Proceeds from the second annual event, held at Fox Run Golf Club in ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... ) has ... Future Horizons and Growth Strategies in the ... Shares, Country Segment Forecasts, Competitive Intelligence, Emerging ... --> ) has announced the ... and Growth Strategies in the German Drugs ...
(Date:11/26/2015)... Nov. 26, 2015 Research and Markets ( ... "Advanced Wound Care Market by Type (Dressings, Therapy Devices, ... (In-Patient Facility, Out-Patient Facility), and Geography - Global Forecast ... --> --> The purpose ... and forecast of the global advanced wound care market. ...
(Date:11/26/2015)... , November 26, 2015 ... --> adds "Global Repaglinide ... "Investigation Report on China Repaglinide Market, ... forecasts data and information to its ... . --> ...
Breaking Medicine Technology: