Practical ways of reducing cigarette cravings. Robert West Cancer Research UK and UCL UK National Smoking Cessation Conference June 2005

Transcription

1 Practical ways of reducing cigarette cravings Robert West Cancer Research UK and UCL UK National Smoking Cessation Conference June 2005

2 Outline What are cravings? The role of cravings in addiction What causes cigarette craving? Managing cigarette craving Conclusions

3 Cravings A term loosely used to describe feelings of need, urge or desire Has been used in addiction research to refer to more abstract concepts: Automatic processes the motivate drug seeking behaviour A cluster of psychological and physical withdrawal symptoms and signs Better to stay with terms that people understand: desire and urge

4 What is the target of cigarette cravings? Desires and urges to smoke Seem out of proportion to the pleasure that smoking provides or the unpleasantness of withdrawal symptoms Seem to focus on the sensations and activity associated with smoking more than the pharmacological effect per se Seem to follow the temporal pattern of a homeostatic drive such as hunger but with more cue-reactivity

5 Five levels of motivation Plans: mental representations of future actions + degree of commitment p r i m e West, R. (2005) Theory of Addiction, Blackwells, Oxford. Responses: Starting stopping and modifying actions Impulses/inhibitions: can be consciously experienced as urges Motives: can be consciously experienced as desires/wants Evaluations: evaluative beliefs

6 The motivational system Emotional states (e.g. happiness distress) Arousal Drives (e.g. hunger) Stimuli/information Evaluations (e.g. beliefs) Motives (e.g. wants) Impulses/inhibitions (e.g. urges) Responses (starting, modifying or stopping an action) Delaying factors Initiating factors Delaying factors Initiating factors Plans (mental representations of actions plus commitment)

7 Cravings and the p.r.i.m.e. theory Need to focus on motivation to smoke At any one time whether a person starts to smoke a cigarette depends on the strength of the impulse to smoke compared with inhibitory force The impulse to smoke can be experienced as an urge but can be unconscious/automatic The inhibitory force can be felt as effortful restraint Impulses can derive from cues, drives or desires

8 Origins of the impulse to smoke Direct response to a trigger or cue because nicotine in the presence of the cue has reinforced the activity (urge) Direct response to an acquired drive arising from chronic nicotine intake (urge) Response to motives (desires) in which smoking or its effects are sought after Response to beliefs and potentially beneficial effects (evaluations)

9 The importance of expectation Dols et al, Addiction. 2002;97: daily smokers ratings of craving using visual analogue scale in presence or absence of smoking cues with or without expectation of smoking cues increased craving only in smokers expecting to smoke

10 Nicotine-free cigarettes Eid et al Pharmacol Biochem Behav. 2005, 81: Up to 4 hours of abstinence 8 heavy smokers conventional cigarettes (1.1mg) versus denicotinised cigarettes (0.07mg) Nicotine-free cigarette reduced craving measured by QSU and Schu-Stitzer scale to similar degree to conventional cigarettes But a similar result was obtained with heart rate: either this is also subject to conditioning or the cigarettes did deliver nicotine

11 Nicotine gum Shiffman et al Psychopharm 2003; 166: smokers after 3 days of abstinence Cue-elicited craving measured using 5-item scale Cue was holding lit ownbrand cigarette Only some smokers reacted to cues Active and placebo gum both initially reduced craving in reactors but active gum reduced it more after 15 minutes

12 Nicotine patches Teneggi et al Psychopharm 2002; 164: volunteers 21 mg versus placebo patches in cross-over design with 10 day washout No difference in craving between smoking and NRT; both lower than placebo

13 Nicotine patches Tiffany et al J Consult Clin Psychol. 2000;68: smokers abstaining during one day 21mg patch versus placebo Patch reduced craving but had no differential effect on cue-elicited craving

14 Nicotine nasal spray Hurt et al Psychopharm 1998;140: smokers, overnight abstinence 1mg nasal spray, 4mg gum and matching placebos Visual analogue scales Active spray was only condition showing significant reduction in craving Open squares: Placebo spray Open circles: Placebo gum Closed circles: Active gum Closed squares: Active spray

15 Comparing forms of NRT West et al (unpublished) 159 smokers abstinent for 1 week 16mg patch vs 2mg gum/microtab/lozengevs nasal spray Measures taken at end of week Top panel: urges to smoke less strong on patch than oral or nasal (p<.01) Bottom panel: units used good for patch, low for oral and spray Units per day Rating (1-6) Difficulty not smoking Strength of urges Patch Oral Nasal Time (mins) Patch Oral Nasal spray Time (mins)

16 Melatonin Zhdanova et al.pharmacol Biochem Behav. 2000; 67: smokers, 20+ cigs per day Crossover design 0.3mg melatonin versus placebo; peak at 13h Visual analogue craving scale Significant reduction in craving

17 Glucose tablets West CNS Drugs. 2001; 15:261-5 Smokers who light up within 30 min of waking Overnight abstinence - tested pm the next day Top panel (N=38): 12g of glucose vs Nicomed placebo Bottom panel (N=51): 12g vs 6g glucose vs placebo Rating strength of desire to smoke every 5 minutes for 20 minutes Both studies: significant reduction in desire to smoke Rating Rating Time (mins) Placebo Glucose Placebo Low High Time

18 Glucose solution Berlin et al Psychopharm 2005; 178: smokers; abstinent overnight; cross-over design 75g vs 32.5g vs placebo in 200ml of water Both glucose doses (filled markers) decrease craving relative to placebo Confirms the concept but the glucose dose is very high (10 to 20 glucose tablets)

19 Walking Taylor et al Psychopharm 2005 In press 15 smokers overnight abstinent self-paced 1-mile walk reduced desire to smoke during (T2), immediately after (T3), 10 minutes after (T4) and 20 minutes after (T5)

20 Muscle tension Ussher et al, unpublished 60 dependent smokers overnight abstinence Isometric muscle exercise reduced desire to smoke Mean change in ratin Pre Post 5 min 10 min 15 min 20 min Time point Isometric exercise Muscle Focusing Control

21 Methods that could be tested Escaping the situation Re-interpreting the feeling of urge Performing a distracting activity Drinking water Eating a healthy snack Manipulating an object Calling a helpline Self-labelling (smoking is not an option)

22 Making sense of the evidence Early in the quit attempt the urge to smoke at any given time stems from: desires and impulses to smoke arising from an acquired drive state that is present throughout the day but declines over time Solution: patches, bupropion, glucose emotional states (e.g. stress) that modulate the desires and impulses Solution: avoidance or coping mechanisms environmental factors that draw attention to the drive or fail to draw attention away from it. Solution: avoid reminders and keep busy impulses to smoke in the presence of particular cues arising from habitual stimulus-response links. Solution: acute nicotine replacement products, nicotine-free cigarettes desire to smoke arising from explicit memories of pleasure of smoking. Solution: change the way the smoker views smoking desire to smoke arising from beliefs about benefits of smoking for particular purposes (e.g. stress relief). Solution: educate the smoker about the genuine effects of smoking

23 The future Services are well placed to study methods of reducing with desires and urges that people try Needs good documentation and standardised measures Could get rapid answers to important practical questions In the meantime: patch/zyban plus oral/nasal NRT should deal the drive and cue-reactive impulses isometric exercise or walking offers promise for reducing desire to smoke glucose or sucrose may be useful with acute desire to smoke