Nicotine receptors take over a month to normalize after quitting
Monday, November 16, 2009
Jonathan Foulds, MA, MAppSci, PhD
In the study, 19 heavy smokers and 20 non-smokers underwent brain scans using single photon emission topography (SPECT) which can measure the density of beta-2 nicotine receptors. The smokers were also scanned at various time-points after quitting smoking. During the first 4 weeks after quitting, the ex-smokers had 20-30% more nicotine receptors, but the number had normalized to that of never-smokers by weeks 6-12. The time-course of these changes is similar (though not identical) to that consistently found for studies of nicotine withdrawal symptom severity, and may reflect a readjustment process in the brain.
Studies like this one are technically difficult and expensive to do, as brain-scanning itself is an expensive business, and some of the methods for assessing specific nicotine receptor numbers have only recently been developed. But the evidence from this and similar studies supports the idea that nicotine withdrawal is related to the number of vacant nicotine receptors, and that it takes just over a month after quitting for these to normalize.
Of course, this doesn’t mean that nicotine addiction is all over six weeks after the last cigarette. It just means that the acute nicotine withdrawal phase is largely gone within that time frame.
A nice summary of the study with a picture of the brain scans can be found at:
http://www.nida.nih.gov/NIDA_notes/NNvol22N4/Abstinent.html
Reference
Cosgrove KP, Batis J, Bois F, Maciejewski PK, Esterlis I, Kloczynski T, Stiklus S, Krishnan-Sarin S, O'Malley S, Perry E, Tamagnan G, Seibyl JP, Staley JK. Beta-2 nicotinic acetylcholine receptor availability during cute and prolonged abstinence from tobacco smoking. Arch Gen Psychiatry. 2009 Jun;66(6):666-76
Labels: brain imaging, jonathan foulds, nicotine, nicotine withdrawal, receptors, SPECT
9 Comments:
At Mon Nov 23, 06:31:00 AM 2009,
Georgene said…
Does it follow, a smoker who has quit is still suffering from nicotine withdrawal for up to 12 weeks?
At Mon Nov 23, 10:46:00 AM 2009,
Jonathan Foulds, MA, MAppSci, PhD said…
Georgene,
We know from studies of reported withdrawal symptoms (e.g. irritability, poor concentration etc) that these have, on average, normalized within 4 weeks. But of course that is the average and we are all a little different. Because PET scans are rather labor-intensive and expensive to do, this new study had only a relatively small number of people at each follow-up point. My guess is that if the study could be done on a larger number of quitters (hundreds rather than tens) that the final result in terms of time for receptors to normalize, would likely be closer to 4 weeks also. But thats just my hunch. We have data on reported withdrawal symptoms in thousands of smokers, suggesting these have typically normalized within 4 weeks.
At Tue Dec 15, 11:52:00 AM 2009,
Debrazgalaxy said…
Will my brain EVER learn to produce its OWN 'happy chemicals'?
6 weeks of minimal nicotine replacements... and two weeks of NO nicotine. I was born to smokers and have a 35 yr addiction. I do NOT ever want to go back to smoking~ I keep telling myself that 'tomorrow' I will feel like a normal useful person again.
HELP~
deb~
At Wed Dec 16, 09:56:00 AM 2009,
Jonathan Foulds, MA, MAppSci, PhD said…
Debrazgalaxy,
We are all a little different, but the evidence suggests that for the vast majority of ex-smokers, their mood has returned to normal within about 4 weeks of last nicotine use, and thereafter most smokers rate themselves as LESS stressed (generally) than while they were smoking. My advice right now is to to treat yourself to some indulgence or activity...the kind of thing that in the past has been fun or lifted your mood..a nice meal, a social event, a trip to the hairdresser, you name it. This way you might lift your mood and start feeling your normal self more quickly.
At Thu Dec 17, 06:54:00 AM 2009,
Debrazgalaxy said…
I appreciate your information and your human heart that responded with such care.
Knowing that millions have survived quiting helps, and knowing that there are people who are willing to be helpful eases some of the pressure. I do HAVE more good moments than bad at this point, so I know I am going in the right direction~
Quiting makes one evaluate many facets of future and past~ and brings us a new strength.
Thank YOU.
Merry Christmas too~ Savor each moment~
At Fri Dec 25, 06:49:00 PM 2009,
jc19934 said…
What's the best way to quit without disrupting the receptors that cause anxiety?
At Mon Dec 28, 03:34:00 PM 2009,
Debrazgalaxy said…
JC19934~ I am not the kind doctor ~ however I wish to help you.No matter which method you choose ..you will have some stress. Just KNOW that anxiety is JUST a feeling. OWN it as such and do NOT let it disable your senses. KNOW that it passes if you do NOT let it fester, bubble and GROW.
The angst and sadness that you overcome will empower you in MANY areas of your life friend.
IT IS worth it!!
(35 yr smoker~10 wks quit~ 4 wth no nicotine...)
At Mon Feb 01, 03:24:00 AM 2010,
Ryan said…
Thank you for putting this up!
At Mon Feb 01, 09:12:00 AM 2010,
Anonymous said…
Ryan~
there is another very helpful site that I found a couple days ago~ WISH I HAD it in the begining!! IT verified what I LEARNED about caffeine effects NOW that we don't smoke. Caffeine IS MORE POTENT with out nicotine to curb it some~ decreasing to 1/4 of my caffeine HELPED A LOT~
(read : CURE)
www.whyquit.com
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