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Uncertainty remains about the long-term effects of acupuncture on smoking cessation, in the absence of sufficient evidence from rigorous trials.1 There is even less evidence involving ‘hard to reach’ smokers, and we know of no previous studies involving smokers with drug dependence. In her linked paper,2 Stuyt reports the provision of auricular acupuncture as an option in a residential drug rehabilitation unit for 231 patients, many with drug dependence and personality disorder (dual diagnosis). Those who chose acupuncture showed several apparent benefits in comparison with those who did not, including improved programme completion rates and increased long-term smoking cessation. It should be emphasised that the study was naturalistic with all the advantages that brings (eg, patients’ behaviour and choices are not distorted by rigid trial procedures), but also with several limitations from an evidence-based aspect, including non-randomisation of patients and no chemical validation of smoking cessation.
The 10% quit rate for smoking cessation at 1 year seems to be a highly respectable figure in this population with high dependence on chemical substances, and further research is justified to replicate the effects in a randomised controlled trial (RCT). Stuyt's paper also highlights other variables that modify the effect and must be taken into account in such studies, including personality disorder, motivation and use of other simultaneous interventions and other mood-altering substances. Additionally, the effect of acupuncture might be small, and definitive studies will require large samples. But funding in this area is difficult, especially until the plausibility of acupuncture is better established. Where do we go from here?
Another intervention for smoking cessation provides a fascinating parallel for acupuncture: physical activity and exercise.3 Exercise has similar potential, and also has plausible mechanisms in general terms, including distraction and psychophysiological processes. The principal targets of exercise and acupuncture are similar—that is, the cravings and other withdrawal symptoms, and (if treatment is continued) weight gain after stopping smoking. Both have similar associated benefits such as improved sleep that could be highly relevant; similar uncertainties about whether doses used in studies are of sufficient intensity; and uncertainties about scheduling the intervention, including whether any effects might accumulate over time. Even the state of the evidence is somewhat similar, in that a reasonable number (15) of RCTs, with at least a 6 month follow-up on smoking outcomes, qualify for inclusion in the Cochrane Review of exercise (compared with 11 for acupuncture), but many are small and use highly diverse methods, dose of intervention and co-interventions. Three studies show an effect of exercise at the end of treatment, and one of these shows a borderline effect at 12 months. Several others show trends. Just as for acupuncture, readers are left with the suspicion that the research fails to test the intervention adequately, mainly stumbling over methodological problems.
Publications on exercise contain one research model that might be applicable to acupuncture research—namely, the use of acute experiments in smokers who have abstained overnight, testing the immediate effects of exercise on withdrawal symptoms and/or cravings. In a recent review of the effects of exercise, data for individual participants were obtained from 15 studies that had used the same measure of urge or strength of urge to smoke, and a meta-analysis helped to identify a strong effect of exercise on cravings compared with a passive control condition.4 A related review showed that the effects were greater for moderate and vigorous intensity exercise, compared with light or no exercise, but no other variable (eg, change in affect) moderated or mediated the effects.5 The latter review was particularly important since moderate intensity exercise may be more appealing than vigorous exercise and the evidence is now clear that exercise does not have to be vigorous to be a useful aid for managing cravings. These studies were nearly all carefully controlled studies in which cravings were increased through required temporary abstinence, and no other nicotine use. So we know that when cravings are high, exercise is clearly valuable. In the few studies in which smokers were attempting to quit and using nicotine replacement therapy, the effects were not so great because baseline cravings were lower.
A number of acute studies have also attempted to identify the mechanisms related to reduced cravings after exercise, using technology such as functional MRI6 ,7 and attentional bias methods.8 ,9 The effects appear to be mostly unrelated simply to distraction, and may be due to changes in the way we process information/images about addictive substances, especially in a state of wanting. But one major lesson from exercise studies is that smokers are most likely to learn to appreciate the potential benefits of managing cravings if they exercise when urges to smoke are at their strongest. Exercising just after smoking or while using nicotine products such as patches or e-cigarettes is unlikely to be perceived to have any benefit if cravings are low anyway, and in this case exercise uptake and adherence could be low.
This is again paralleled by the strong suggestion in the updated acupuncture review1 that continuous auricular stimulation, where needles or beads can be pressed whenever cravings occur, does have an effect. Caution is needed because the effect is not seen when the analysis is restricted to studies with needles, which presumably administer a higher ‘dose’ than beads, and because the analysis is technically a subgroup analysis and therefore only hypothesis-generating. Such laboratory-based studies would be relatively easy to organise and require small sample sizes, and could quickly provide evidence on the potential value of acupuncture, and optimal dosing. These acute studies using a ‘proof-of-concept’ approach with cravings as a surrogate outcome and control participants who only need to receive a placebo or inactive condition are much more feasible than chronic studies in which it is ethically challenging to deny usual care.
Competing interests AW has received editorial fees, lecture fees and travel expenses from the British Medical Acupuncture Society, but not in relation to this work. AT no competing interests.
Provenance and peer review Commissioned; internally peer reviewed.
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