Why people smoke
Symptoms of nicotine withdrawal
Much of the intractability of cigarette smoking is thought to stem from the problems of withdrawal symptoms —particularly irritability, restlessness, feeling miserable, impaired concentration, and increased appetite —as well as from cravings for cigarettes. These withdrawal symptoms begin within hours of the last cigarette and are at maximal intensity for the first week. Most of the affective symptoms then resolve over three or four weeks, but hunger can persist for several months. Cravings, sometimes intense, can also persist for many months, especially if triggered by situational cues.
Social and behavioural aspects
The primary reinforcing properties of nicotine ultimately sustain smoking behaviour: in experimental models, if nicotine is removed from cigarette smoke, or nicotine’s effects on the central nervous system are blocked pharmacologically, smoking eventually ceases. However, under normal conditions, the intimate coupling of behavioural rituals and sensory aspects of smoking with nicotine uptake gives ample opportunities for secondary conditioning. For a 20 a day smoker, “puff by puff” delivery of nicotine to the brain is linked to the sight of the packet, the smell of the smoke, and the scratch in the throat some 70 000 times each year. This no doubt accounts for smokers’ widespread concern that if they stopped smoking they would not know what to do with their hands, and for the ability of smoking related cues to evoke strong cravings.
Regulation of nicotine intake: actual and predicted intake per cigarette from
low tar cigarettes. Data from health survey for England, 1998
Social influences also operate to modulate nicotine’s effects.
Key points
- Smoking usually starts as a symbolic act of rebellion or maturity
- By age 20, 80% of smokers regret having started to smoke
- Nicotine from cigarettes is highly addictive —probably because it is delivered so rapidly to the brain
- Smoking a cigarette, especially the first of the day, feels good mainly because it reverses the symptoms of nicotine withdrawal
- Most smokers who switch to low tar cigarettes or reduce the number of cigarettes they smoke continue to inhale the same amount of nicotine, and hence tar, from the cigarettes they smoke
- Heavy dependence on nicotine is strongly related to socioeconomic disadvantage
- Smoking is a chronic relapsing addictive disease
The direction of this influence can be to discourage smoking —as,for example,with the cultural disapproval of smoking in some communities, the expectation of non-smoking that has become the norm in professional groups, or the effects of smoke-free policies in workplaces. Other factors encourage smoking, such as being married to a smoker or being part of social networks in socially disadvantaged groups, among whom prevalence is so high as to constitute a norm.
Regulation of nicotine intake
Smokers show a strong tendency to regulate their nicotine intakes from cigarettes within quite narrow limits. They avoid intakes that are either too low (provoking withdrawal) or too high (leading to unpleasant effects of nicotine overdose). Within individuals, nicotine preferences emerge early in the smoking career and seem to be stable over time. The phenomenon of nicotine titration is responsible for the failure of intakes to decline after switching to cigarettes with low tar and nicotine yields. Compensatory puffing and inhalation, operating at a subconscious level, ensure that nicotine intakes are maintained.
As nicotine and tar delivery in smoke are closely coupled, compensatory smoking likewise maintains tar intake and defeats any potential health gain from lower tar cigarettes.
Nicotine intake and social deprivation. Data from health survey for England
(1993, 1994, 1996)
Similar compensatory behaviour occurs after cutting down on the number of cigarettes smoked each day; hence this popular strategy fails to deliver any meaningful health benefits.