1. New evidence and theories about why people smoke
Robert West
University College London
March 2008

2. Outline Cigarette addiction in the UK
The common-sense model of why people smoke
A fuller understanding of human motivation
Mechanisms of addiction to cigarettes and the role of nicotine
Psychological factors in why people smoke
The process of smoking cessation
Implications for interventions to promote smoking cessation

3. Cigarette addiction in England
See

4. How can cigarette addiction be assessed in smokers? The FTND
1. How soon after you wake up do you smoke your first cigarette? (Circle one response)
Within 5 minutes
6-30 minutes
31-60 minutes
More than 60 mins 3 2 1
2. Do you find it difficult to stop smoking in no-smoking areas? (Circle one response) No
Yes
3. Which cigarette would you hate most to give up? (Circle one response)
The first of the morning
Other
4. How many cigarettes per day do you usually smoke? (Write the number on the line and circle one response)
_________ per day
10 or less
11 to 20
21 to 30
31 or more
5. Do you smoke more frequently in the first hours after waking than during the rest of the day? (Circle one response)
6. Do you smoke if you are so ill that you are in bed most of the day? (Circle one response)

5. The common sense model of smoking
People do what they most desire at a given moment
What keeps them smoking is that:
enjoyment of smoking and needs met by smoking put them off trying to stop despite the health concerns and cost
when they try to stop, the anticipated enjoyment of smoking or relief from unpleasant feelings overwhelm their resolve to remain abstinent
Nicotine is the addictive ingredient in cigarettes because it:
gives an enjoyable feeling
meets certain needs such as stress-relief
relieves withdrawal symptoms caused by nicotine depletion

6. Seven steps to a fuller understanding of human motivation
Many stimuli can generate the impulse to act without the person having any conscious desire or goal
Ability to inhibit impulses because of desires (such as the desire to stick to a plan or avoid unpleasant consequences) vary from person to person and over time as a function of internal and external factors
Desires (feelings of wanting or needing something) can apply as readily to an activity as the expected outcome of that activity
Desires and impulses to engage in an activity are typically more strongly established and resistant to extinction if they are rewarded only intermittently

7. Seven steps to understanding motivation
Beliefs about what is good or bad etc. probably only influence behaviour if they generate desires
Plans/intentions have to be remembered and activate sufficiently strong desires for them to have any effect on behaviour
The exercise of self-control (resisting or generating impulses to act because of desires borne out of plans) is effortful and uses up mental energy

8. The mesolimbic dopamine pathway
The central ‘reward’ pathway
Nucleus accumbens (NAcc)
Ventral tegmental area

9. Drug actions on the mesolimbic pathway

10. Multiple actions of nicotine
A small rapid increase in brain nicotine concentrations (from about 1mg in 10 minutes):
is slightly pleasant to some individuals if there has been no nicotine ingestion for an hour or more (through dopamine release in the NAcc shell)
causes activities that are associated with it to become desired (through dopamine release in the NAcc core)
A low dose of nicotine (about 1mg in humans) makes mildly rewarding stimuli that present at the time, more rewarding (probably through dopamine release in the NAcc shell)
Repeated administration of nicotine leads to:
increased responsiveness of the NAcc shell even if the nicotine is not response contingent
increased responsiveness of the NAcc core only if the nicotine is response contingent
reduction in sensitivity of the NAcc shell to other rewarding stimuli
reduction in tonic level of dopamine in the NAcc

11. What this means psychologically?
Nicotine per se is not particularly addictive: people do not inject it or take it using delivery systems that do not have other rewarding properties
Nicotine from a cigarette makes the cigarette addictive in a way that can only be partially substituted for by other nicotine delivery systems:
the activity of smoking a cigarette becomes desired, including inhaling the smoke
mildly rewarding features of smoking such as the taste and smell take on strongly rewarding properties
Nicotine substitution can relieve some of the need to smoke by raising the tonic depression of NAcc activity; they can do this without themselves being addictive

12. Mechanisms of cigarette addiction 1: Reward and the urge to smoke
When nicotine is absorbed it attaches to nicotinic acetylcholine receptors in the Ventral Tegmental Area (VTA) of the mid brain
This stimulates firing of neurons that project forward to the Nucleus Accumbens (NAcc)
This causes dopamine release in the NAcc
This results in an impulse (urge) to smoke in situations that have been associated with smoking

13. Mechanisms of nicotine addiction 2: Acquired drive
In many smokers, after repeated ingestion of nicotine, the motivational system is altered to create a ‘drive’, somewhat similar to hunger, except that it is for cigarettes
The drive increases in the minutes to hours since the last cigarette and is influenced by triggers, reminders, stress and distractions
The drive is experienced as a need to smoke
It usually reduces over weeks of not smoking but can re-emerge unexpectedly
Relief from this need can be pleasurable and memory of the pleasure makes smokers feeling that they ‘want’ to smoke: the expect to enjoy it

14. Mechanisms of nicotine addiction 3: avoidance and escape
After repeated nicotine exposure, abstinence results in unpleasant withdrawal symptoms including depression
Smokers also report that smoking helps them cope with stress
Adverse mood therefore comes to generate a need to smoke
Smoking intermittently reinforces this and this establishes a strong pattern of behaviour

15. Motivation to smoke
Smoking
Impulse to smoke
Cues/triggers
Anticipated pleasure/ satisfaction
Want to smoke
Need to smoke
Nicotine ‘hunger’
Unpleasant mood and physical symptoms
Anticipated benefit
Reminders
Positive evaluations of smoking
Smoker ‘identity’
Beliefs about benefits of smoking
Plan to smoke
Nicotine dependence involves generation of acquired drive, withdrawal symptoms, and direct simulation of impulses through habit learning

16. Mechanisms of nicotine addiction 4: Weakened impulse control
After repeated nicotine exposure, there may be a reduction in the ability to inhibit responses

17. Inhibition of smoking
Not smoking
Inhibition
Cues/triggers
Anticipated praise
Want not to smoke
Need not to smoke
Anticipated disgust, guilt or shame
Fears about health
Anticipated self-respect
Positive evaluations of not smoking; negative evaluations of smoking
Reminders
Beliefs about benefits of not smoking
Non-smoker ‘identity’
Plan not to smoke
Nicotine dependence probably also involves impairment of impulse control mechanisms undermining response inhibition

18. Smokers’ reasons for smoking
928 smokers in clinic asked to rate importance of various motives
Enjoyment, boredom relief and stress relief are highest
But none of them predict relapse
Enjoyment of smoking predicts not attempting to stop but is not related to ability to maintain abstinence

19. The basic principles of behaviour change
Initiation
Dissatisfaction with the present situation
Hope that an alternative will be better
Perceiving a path towards the better alternative
Maintenance
Sustaining desire for the new behaviour
Self-regulatory skills to enable that desire to control behaviour in the face of other desires

20. The process of cessation
Smokers feel varying levels of worry about their smoking
Usually this is not enough to provoke a quit attempt but often results in them trying to ‘cut down’
Occasionally a ‘trigger’ results in hem making a quit attempt
In half these cases the attempt is put into effect immediately; these appear more likely to be successful
Using ‘treatments’ to aid cessation can improve success rates up to 300 percent:
behavioural support
medication

21. The future Cultural shifts Reducing occasions when smoking is possible
Better use of NRT
preloading
combination therapy
Better medications for cessation
Alternatives to smoking