Plain English Summary
Background and study aims
Scientists believe that hypnosis may help people stop smoking, but studies show unclear results. At the same time, people who want to give up smoking are not always able and willing to attend several sessions of therapy or to use medication. Therefore, we are investigating whether a single hypnosis session helps smokers quit smoking.
Who can participate?
You are invited to participate in the study if you are older than 18 years, if you smoke at least five cigarettes per day, if you want to quit and if you are not trying to give up smoking in any other way.
What does the study involve?
You will attend a 40-minutes session of motivational training then you will be randomly allocated to attend a 40-minute group session of either hypnosis or relaxation. You will attend the session together with 10-15 other people. A trained hypnotherapist and relaxation instructor will lead the session.
What are the possible benefits and risks of participating?
There are no risks for you because hypnosis has hardly any side effects in healthy people. The results will provide information to tobacco prevention organisations in Switzerland on whether or not to recommend hypnosis as a method to stop smoking.
Where is the study run from?
Institut für Sucht- und Gesundheitsforschung (ISGF) (Switzerland).
When is the study starting and how long is it expected to run for?
The study ran from April 2011 to June 2012.
Who is funding the study?
Tobacco Control Fund (Switzerland).
Who is the main contact?
Dr Michael Schaub
Dr Michael Schaub
Smoking cessation through group hypnosis: a randomised controlled trial
A one-time session consisting of mental preparation followed by hypnosis or relaxation in a group setting helps smokers quit smoking. We hypothesise that 6 months following the intervention, at least 30% of participants in the hypnosis group and at least 18% of participants in the relaxation group will be abstinent.
Cantonal Ethical Committee of Zurich, 25/08/2010
Single-centre randomised controlled double-blind study with repeated measurements
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Patient information can be found at http://www.isgf.ch/index.php?id=94&no_cache=1&tx_ttnews[tt_news]=27&tx_ttnews[backPid]=9&cHash=859b89b6fa6ac5bd25fa181c4e58ae97%20 [German]
Public health, smoking, hypnosis, smoking cessation
Two groups to be compared:
1. Participants receive 40 minutes of motivational training followed by 40 minutes of hypnosis in a group session (8 to 15 participants)
2. Participants receive 40 minutes of motivational training followed by 40 minutes of relaxation in a group session (8 to 15 participants)
Motivational training: the intention of the participants to quit smoking is reinforced in an oral presentation given by a trained instructor. The presentation focuses on participants life after smoking cessation.
Group hypnosis: deep relaxation is induced through repetitive statements and soft background music. During the hypnosis, suggestions reinforcing cigarette abstinence are made by a trained instructor.
Group relaxation: relaxation is induced through soft music. During the relaxation, suggestions reinforcing cigarette abstinence are made by a trained instructor.
All participants are contacted 2 weeks and 6 months following the intervention in order to check their smoking status, mental and physical health.
Primary outcome measure
1. Number of participants smoking 2 weeks after each intervention (smoking defined as 5 or more cigarettes per day) (inter-subject design)
2. Number of participants smoking 6 months after each intervention (inter-subject design)
3. Changes in the number of daily cigarettes smoked from baseline to 2 weeks after the intervention (intra-subject design)
4. Changes in the number of daily cigarettes smoked from baseline to 6 months after the intervention (intra-subject design)
5. Changes in salivary cotinine levels from baseline to 6 months after the intervention (intra-subject design)
Secondary outcome measures
1. Depression (BDI-V, Schmitt et al. 2003; 2006) at baseline, 2 weeks and 6 months after the intervention
2. Anxiety (BAI, Beck et al. 1988, German version by Margraf & Ehlers) at baseline, 2 weeks and 6 months after the intervention
3. Expected self-efficacy in situations of high smoking temptation (Tönjes et al., 2007) at baseline and 2 weeks after the intervention
4. Adverse events (headache, insomnia, gastrointestinal problems etc.) 2 weeks and 6 months after the intervention
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged between 18 and 65 years
2. Smoking five or more cigarettes per day
3. Not taking any medication or following another program for smoking cessation
4. Willing to stop smoking
5. Not suffering from alcohol dependence or psychotic disorders
6. No intake of stimulating medication such as methylphenidate (Ritalin) or venlafaxine (Effexor®)
Target number of participants
Participant exclusion criteria
Does not meet inclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Tobacco Control Fund (Switzerland)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24365274
Dickson-Spillmann M, Haug S, Schaub MP, Group hypnosis vs. relaxation for smoking cessation in adults: a cluster-randomised controlled trial., BMC Public Health, 2013, 13, 1227, doi: 10.1186/1471-2458-13-1227.