Treatment effectiveness of hypnosis and behaviour therapy in smoking cessation: a methodological refinement.

Studies in smoking cessation have generally failed to adequately control for active treatment effects and have assumed that measures of smoking behaviour (i.e., estimated smoking rate, self-monitoring and chemical analysis) are equally reliable measures. Sixty smokers were randomly assigned to one of four different smoking cessation treatment groups: hypnosis, focussed smoking, attention placebo and a waiting list control. Subjects were asked to estimate and monitor their own smoking behaviour. Blood samples were also taken for thiocyanate analysis before treatment. Smoking rates were similarly measured directly, at 3 months and 6 months after treatment. The results indicate that the three measures of smoking behaviour were all highly correlated. No significant differences were found between treatments, directly after treatment or at the 3- and 6-month follow-ups. These results suggest that active treatment effects may not be responsible for behavioural change in a smoking cessation program. The implications of these findings are discussed.