Hooked from the first cigarette

What happens in the brain after just one smoke?

As you would expect, long-term smokers have higher concentrations of nicotine receptors in the brain, according to autopsy studies,¹¹ but what happens to the brain after, say, just one cigarette? A study by Dr Abreu-Villaca and colleagues revealed that there is an increase in nicotine receptors in the brain the day after the first dose of nicotine. The take-home message: It only takes a day for the brain to remodel itself in response to one dose of nicotine.¹²

It’s time to revisit our beliefs about withdrawal

Just as we have been taught that people who smoke just a few cigarettes daily are rarely addicted, so too, have we been taught that occasional smokers are unlikely to experience withdrawal symptoms. Our understanding has been that smokers who experience withdrawal must smoke frequently enough to maintain nicotine in the blood throughout their waking hours. With nicotine’s two hour half-life, this typically requires 5 cigarettes per day. In fact, some years ago, The New England Journal of Medicine published a proposal that cigarettes could be rendered practically non-addictive if their nicotine content was lowered to the point where smokers would not be able to obtain as much nicotine as was delivered by 5 ordinary cigarettes.¹³

PATIENT HANDOUT

Hooked On Nicotine Checklist

Are you skeptical that addiction can begin so quickly, after just a few cigarettes? Then complete this checklist.

A Yes response to any of the questions means you are already addicted to cigarettes. The number of Yes responses indicates how dependent you are on them.

		Yes	No
1.	Have you ever tried to quit smoking, but couldn’t?
2.	Do you smoke now because it is really hard to quit?
3.	Have you ever felt like you were addicted to tobacco?
4.	Do you ever have strong cravings to smoke?
5.	Have you ever felt like you really needed a cigarette?
6.	Is it hard to keep from smoking in places where you are not supposed to, like school?

When you tried to stop smoking (or, when you haven’t used tobacco for a while):

7.	Did you find it hard to concentrate because you couldn’t smoke?
8.	Did you feel more irritable because you couldn’t smoke?
9.	Did you feel a strong need or urge to smoke?
10.	Did you feel nervous, restless, or anxious because you couldn’t smoke?

But a growing body of literature paints a different picture. We now know that tobacco withdrawal does, indeed, occur in those who do not smoke daily or who smoke fewer than 5 cigarettes per day.^6-8,14-20

In fact, a survey of adult smokers found that adults who smoked only a few cigarettes weekly found quitting to be difficult; they experienced withdrawal symptoms, which some rated as unbearable.²¹ Most of these self-described “social smokers” were addicted to tobacco.

Timing of withdrawal is different for novice smokers

Although the Diagnostic and Statistical Manual of Mental Disorders-IV-TR defines nicotine withdrawal as beginning within 24 hours of the last cigarette, the timing of withdrawal had been studied only in heavy smokers. It was surprising to find in an as yet unpublished survey that my colleagues and I conducted that some high school smokers experienced withdrawal symptoms that did not appear until a week after their last cigarette. This period of time is defined as the latency to withdrawal, or the time from the last cigarette to the onset of withdrawal.²² When novice smokers first experience withdrawal symptoms, the latency to withdrawal is very long, allowing them to remain comfortable for a week or more between cigarettes.

How could a single cigarette keep withdrawal symptoms at bay for far longer than the 12 hours it takes to eliminate nicotine from the body? We don’t know what the answer is for humans, but we do know that in rats, the first dose of nicotine increases noradrenaline synthesis in the hippocampus for at least 30 days after the nicotine is gone.²³ Given this information, it is quite plausible, then, that a few puffs from a cigarette could suppress withdrawal for many days, and perhaps even several weeks.

Research I conducted—and which I’ll describe in greater detail, in a bit—supports the notion that the latency to withdrawal period may shrink over time. The realization that the latency to withdrawal changes over time fundamentally alters our understanding of addiction.

Revisiting long-held beliefs of addiction and tolerance

The shortening of the latency to withdrawal is called dependence-related tolerance.²⁴ One can think of dependence-related tolerance as either a diminution in the duration of withdrawal relief afforded by one cigarette, or conversely, a requirement to smoke more frequently to maintain comfort. The latency to withdrawal cannot shorten if there is no withdrawal. Therefore, dependence-related tolerance develops only after withdrawal symptoms are present.