Green and Lynn (2000) conducted a meta analysis of 59 experiments investigating the efficacy of hypnosis on smoking cessation. Their conclusions were:
- There is mixed, inconclusive evidence for whether hypnosis is any better than placebos.
- Hypnosis treatments were generally confounded with educational interventions and cognitive/behavioral interventions, making it impossible to isolate hypnosis as the causal source of positive results.
In short, their conclusion is:
Hypnosis cannot, as yet, be regarded as a well-established treatment for smoking cessation
Barnes et al. (2010) ran a meta analysis ten years later, and came to the same general conclusion. There is no evidence that hypnotherapy for smoking cessation works better than no treatment at all. They found that claims of success in the literature are generally uncontrolled studies, and that:
The effects of hypnotherapy on smoking cessation claimed by uncontrolled studies were not confirmed by analysis of randomized controlled trials.
Barnes, J., Dong, C. Y., McRobbie, H., Walter, N., Mehta, M., & Stead, L. F. (2010). Hypnotherapy for smoking cessation. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD001008.pub2
Green, J., & Lynn, S. J. (2000). Hypnosis and suggestion-based approaches to smoking cessation: An examination of the evidence. International Journal of Clinical and Experimental Hypnosis, 48(2), 195-224.