Navigation Links
Brain chemical may explain why heavy smokers feel sad after quitting
Date:8/2/2011

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
media@camh.net
416-595-6015
Centre for Addiction and Mental Health
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:12/10/2016)... ... 2016 , ... Denver-based humanitarian aid organization, Saving Moses, is ... , The situation in Syria continues to worsen—deadly weapon explosions are increasing as ... disease. The situation is intensifying with winter coming and airstrikes increasing. , ...
(Date:12/9/2016)... (PRWEB) , ... December 09, 2016 , ... Cellairis is ... and affordable repairs on iPhone , iPad and Samsung Galaxy devices ... Pearland Walmart in order to maximize convenience and accessibility for customers. While customers ...
(Date:12/9/2016)... ... December 09, 2016 , ... Sober College, ... with the grand opening of the Sober College Robert Pfeifer Memorial Learning Center ... December 2-3, and was attended by an overwhelming amount of alumni, family, colleagues ...
(Date:12/9/2016)... ... December 09, 2016 , ... MEDI+SIGN®, a provider of fully-automated ... new solution for Emergency Departments (ED) has been added to their portfolio. Housed ... examination rooms, and with a simplified pallet of information available to the patient, ...
(Date:12/8/2016)... ... December 08, 2016 , ... The Florida Hospital ... and Hyperbaric Medical Society (UHMS), the leading authority in hyperbaric medicine. This accreditation ... a few hospitals and facilities have earned this distinction. This is the second ...
Breaking Medicine News(10 mins):
(Date:12/9/2016)... DUBLIN , Dec 9, 2016 ... Optical Transceiver Market 2016-2020" report to their offering. ... The report forecasts the ... during the period 2016-2020. The report covers the ... market for 2016-2020. To calculate the market size, the report considers ...
(Date:12/9/2016)... Mitsubishi Tanabe Pharma Corporation (Head Office: ... Dr. Masayuki Mitsuka ) has presented data that ... intravenously in 10-14 day cycles for 48 weeks experienced ... Functional Rating Scale-Revised (ALSFRS-R). The data were presented at ... Dublin, Ireland . In ...
(Date:12/9/2016)... -- Research and Markets has announced the addition of ... offering. ... global travel vaccines market to grow at a CAGR of 6.83% ... scenario and the growth prospects of the global travel vaccines market ... revenue generated from the sales of various vaccines administered to actively ...
Breaking Medicine Technology: