“Boost your immune system with hypnosis” is a popular promise. It sounds plausible: we know stress affects health, and hypnosis reduces stress. So what does the research say?
The mind and the immune system are connected
This part is not in doubt. The field of psychoneuroimmunology has shown that the nervous system and the immune system communicate.
- Chronic stress alters immune function.
- Stressed people catch more colds when deliberately exposed to a virus.
- Wounds heal more slowly under stress.
- Vaccines produce a weaker response in people under long-term strain.
The harder question is whether a psychological technique can push things the other way.
The major review
In 2001, Gregory Miller and Sheldon Cohen published a meta-analysis of more than 85 trials testing whether psychological interventions could change immune measures in humans.
Their overall conclusion was sobering. There was only modest evidence that such interventions reliably alter immune parameters.
Within that, some approaches did better than others:
- Relaxation showed little capacity to produce immune change.
- Stress management and emotional disclosure showed scattered evidence.
- Hypnosis with immune-related suggestions, and conditioning, produced the most consistent evidence, though results varied a good deal between studies.
So hypnosis came out ahead of the alternatives, in a field where the overall effects were small.
The exam studies
Some of the best-known work used medical and dental students, since exams reliably depress certain immune measures.
In research at Ohio State University, students who practised self-hypnosis in the run-up to exams were protected from much of the decline in measures of T-cell activity seen in students who did not. Other researchers in Britain reported similar findings, along with fewer winter infections in students who practised.
Skin reactions
A long line of small studies has looked at whether hypnotic suggestion can change skin reactions to allergens or to the tuberculin test. Some found that suggestion reduced the reaction; others did not. These studies are old, small and inconsistent, but they are part of why researchers take the question seriously.
The gap between a lab value and health
Here is the crucial point. Most of these studies measured immune markers in blood samples: counts of certain cells, or how those cells behave in a dish.
A change in a marker is not the same as being healthier.
- The immune system is a balance, not a dial. More activity is not always better; allergies and autoimmune diseases are overactivity.
- A small shift in a blood measure may make no difference to whether you get ill.
- Very few studies have tracked actual illness.
“Boosting immunity” is a marketing phrase, not a medical one.
What hypnosis cannot do
No good evidence shows that hypnosis can:
- Prevent or cure infections
- Treat cancer or slow its progress
- Treat autoimmune disease
- Replace vaccination
- Replace any medical treatment
Claims of this kind are not supported and can be dangerous if they lead someone to delay care.
What is reasonable to say
- Chronic stress is bad for immune function.
- Hypnosis reduces stress and improves sleep.
- In some studies, self-hypnosis has buffered the immune dip caused by a stressful period.
- So regular relaxation and good sleep may help you stay well during demanding times.
That is a modest claim, and it is the one the evidence supports.
What actually supports your immune system
The dull answers are the right ones:
- Enough sleep
- Regular physical activity
- A varied diet
- Not smoking, and moderate alcohol
- Staying up to date with vaccinations
- Managing long-term stress
- Social connection
Hypnosis can help with the first and the sixth.
A stress-buffering routine
For a demanding period, such as exams, a deadline or caring for someone:
- Ten minutes of self-hypnosis or relaxation daily.
- Slow breathing, then relax the body from head to toe.
- Imagine somewhere restful in detail.
- Suggest: “My body rests deeply and recovers well.”
- Finish with a suggestion for good sleep.
- Keep it up for the whole period. In the exam studies, those who practised more regularly did better.
The bottom line
Hypnosis can change some immune measures, and may soften the effect of stress on them. That is interesting science. It is not evidence that hypnosis prevents or treats disease, and anyone who claims so is going well beyond the data.
Next in the series: Hypnosis for Scans and Medical Procedures
This article is for general information and is not medical advice.