REWARDS, NICOTINE, AND THE BRAIN
Shevlin Ryan 2006

There have been some questions concerning rewards lately. I've been doing research (actually, more like rooting around) into the neurochemical aspects of nicotine addiction and thought I'd share a bit here. It's a bit long so if you want the bottom line, just skip to the colored part and start there.

When you experience something pleasurable, certain areas of your brain called reward centers activate by releasing dopamine. The presence of dopamine is what causes the pleasurable feeling, the enjoyment, the ahhh.

Smoking causes an increase in the dopamine levels. The actual mechanism is debated, but fMRI studies confirm the increase occurs. As you continue to smoke, the dopamine levels remain high and the brain starts shutting down some of the reward centers in an attempt to return to normal. This causes the smoker to require more, which raises the dopamine levels, which causes the brain to shut down even more reward centers. A balance is eventually reached, typically at the point of a pack per day (about 20 mg of nicotine). This also applies to users of chewing tobacco and snuff.

So now a balance has been reached. The nicotine has raised dopamine levels and the brain has shut down reward centers to compensate. Heroin and cocaine users also reach this maintenance level where the fix no longer causes pleasure, but simply maintains normal. When the dopamine level begins to drop (30 60 minutes after the last smoke) the smoker begins to feel the need and has another fix which re-establishes the dopamine levels.

When the smoker quits the levels of nicotine fall rapidly, as do the dopamine levels. After three to five days the nicotine is out of the system. The brain, however, does not recover as quickly. Without the constant smoking stimulus, dopamine levels are far below where they were. Since reward centers were long ago shut down to compensate for the increased dopamine levels caused by smoking, the (now) ex-smoker is operating at a reward deficit. As a result, the ex-smoker feels depressed, ill-tempered, and sad (cries a lot). Those who use sleep as an escape mechanism will tend to sleep much more.

Another effect of this reward deficit is that ordinary, everyday rewards dont seem to work anymore. In reality, they do cause an increase in dopamine levels, but with so many reward centers deactivated the increase is barely noticeable, if it can be noticed at all. This is why we quitters need to reward ourselves often. The size of the reward isnt important, the quantity is. Essentially, we need to exercise our reward centers to rebuild them, just like muscles need to be exercised after a long period of disuse.

The research Ive dug into indicates it takes several months to over a year, (depending on who you read) for the brain to reactivate enough reward centers to approach the normal of never-smokers. Perhaps this is the root of the idea that you arent fully quit until youve experienced all the seasons. I suspect it is part of that idea. The other part is another topic.

So early in your quits, reward yourselves often. Little stuff is great. Window shopping, watching ducks at the park, special coffee after work, whatever. A reward doesnt have to be expensive, just enjoyable. Think free weights for the brain.

Don't smoke, everyone. It's bad for you.
Shevie
Quit May, 2005