Here is a list of conditions and the typical effectiveness of hypnosis/hypnotherapy:
Most improved: pain (acute and chronic), anxiety (including pre‑procedure and some phobias), some habit and symptom control (smoking, insomnia, headaches, irritable bowel symptoms), and procedural distress. Hypnosis is also effective for reducing nausea and vomiting (e.g., chemo) and for enhancing psychotherapy outcomes (e.g., accelerating exposure).
Least changed (poor or inconsistent evidence): core personality traits, long‑term stable psychiatric diagnoses as sole treatment (e.g., schizophrenia, severe bipolar), complex memory retrieval (hypnosis does not reliably recover accurate repressed memories and increases false memories), major cognitive disorders (dementia) and many kinds of severe substance use disorder when used alone.
Longer, evidence‑based overview I’ll break this into categories: where hypnosis has the strongest support, where it’s promising but mixed, and where it’s ineffective or risky. “Hypnosis” below means a therapeutic, suggestive hypnotic intervention delivered by trained clinicians, not stage hypnosis.
Strongest evidence (most improved)
Pain control
Acute procedural pain: strong, consistent evidence that hypnosis reduces pain, anxiety, and analgesic use during procedures (surgery, dental work, burn care, labor). Effects can be large when suggestions target pain reduction.
Chronic pain: good evidence for reducing pain intensity and improving coping for conditions like chronic low back pain, fibromyalgia, and headache. Not a cure, but clinically meaningful symptom reduction and improved function for many patients.
Anxiety and procedural distress
Preoperative and procedural anxiety reliably reduced by short hypnotic interventions; often faster and with fewer side effects than medication for mild–moderate anxiety.
Dental/phobic procedure distress: hypnosis reduces fear and lowers physiological arousal.
Nausea and vomiting
Chemotherapy-induced nausea and vomiting and postoperative nausea respond well to hypnosis, especially when combined with relaxation and expectancies.
Acute symptom control and behavioral symptoms
Headaches/migraines: many trials show fewer attacks and less intensity.
Irritable bowel syndrome: hypnosis (gut‑directed) shows fairly robust benefits for symptoms and quality of life.
Insomnia: hypnotic suggestions and hypnotherapy for sleep can shorten sleep latency and improve sleep quality in many patients.
Procedural tolerability and recovery (less pain, shorter recovery times in some surgery trials).
Supporting psychotherapy
Hypnosis can speed treatment response and increase effectiveness of cognitive‑behavioral therapy (CBT) for targeted problems (e.g., anxiety, phobias, somatic symptoms) when combined with evidence‑based therapy.
Good but mixed evidence (helpful for some people / contexts)
Habit change and addictions
Smoking cessation: small to moderate effects in some studies, but overall evidence is mixed and modest compared with most effective multi‑component programs. Hypnosis can help some smokers but is not a consistently reliable single therapy.
Alcohol and drug dependence: limited and inconsistent evidence; best used as adjunct to comprehensive treatment.
Depression
Short‑term symptom reduction may occur when hypnotic techniques are used with psychotherapies, but hypnosis alone is not a first‑line treatment for moderate–severe depression.
Performance, sports, and exam anxiety
Hypnosis can improve aspects of performance (focus, confidence, anxiety reduction) in many people, though effects vary by individual and trainer skill.
Little or no reliable effect / risky or ineffective uses
Core personality traits and stable temperament
Hypnosis does not produce lasting, broad changes to personality (e.g., make someone extraverted vs introverted).
Severe, chronic psychiatric disorders as sole treatment
Schizophrenia, severe bipolar disorder, severe major depressive disorder: hypnosis is not an established primary therapy and may be inappropriate as sole treatment. It can sometimes assist with symptom management as adjunctive care but should not replace evidence‑based psychiatric treatments.
Dementia and major neurocognitive disorders
Hypnosis cannot reverse neurodegeneration; effects are minimal and symptom relief is limited.
Memory recovery and “recovered” or repressed memories
Hypnosis increases suggestibility and can create false memories. It is unreliable and potentially harmful for forensic or investigative purposes; not recommended for recovering accurate long‑term memories.
Long‑term relapse prevention for many addictions when used alone
Hypnotic single‑session interventions rarely produce durable abstinence without comprehensive behavioral and medical support.
Complex medical cures
Hypnosis helps symptoms and coping, but it does not cure underlying organic disease (e.g., cancer, autoimmune disease).
Why effects differ
Mechanism: hypnosis primarily modifies perception, attention, expectation, and suggestibility. Conditions dominated by perception and physiological arousal (pain, anxiety, nausea, functional GI symptoms) respond best.
Suggestibility and skill: individual hypnotizability varies; higher responsiveness predicts better outcomes. Therapist skill, tailored suggestions, and integration with other therapies matter a lot.
Outcome type: subjective, rapidly modifiable symptoms (pain, anxiety) show stronger and faster effects than stable traits, structural brain disease, or factual memory retrieval.
Practical guidance
For pain, anxiety around procedures, IBS, headaches, insomnia, and nausea: hypnosis is a good option with good evidence; discuss with a trained clinician.
For smoking or addiction: consider hypnosis as an adjunct within a comprehensive program, not a stand‑alone miracle.
Avoid using hypnosis for forensic memory retrieval or as the only treatment for severe psychiatric or neurological disorders.
Effect size depends on patient hypnotizability, therapist experience, and whether hypnosis is combined with proven treatments (e.g., CBT, medical care).