Clinical Hypnosis

Mesmer and the Paris commissions

A 2024 overview of hypnosis in psychotherapy, psychosomatics and medicine traces the field through roughly 250 years. It places the practice of animal magnetism by Franz Anton Mesmer in the period from 1779 to 1784, and reports that in 1784 two scientific commissions in Paris concluded that the phenomena seen in his patients were caused by imagination and not by magnetism. The same overview describes a German Romantic revival of somnambulism between 1800 and 1848 that linked these practices to ideas about the unconscious.

Braid, Charcot and the nineteenth-century clinic

According to the same overview, James Braid introduced the term neurypnology in 1843, and the word hypnosis became established from that period. In the 1880s and 1890s Sigmund Freud studied hypnosis with Jean-Martin Charcot in Paris and with Hippolyte Bernheim in Nancy, Pierre Janet described dissociation and age regression in 1889, and Breuer and Freud published the Anna O. case in 1895. Freud stopped using hypnosis in psychoanalysis from about 1900, although he referred to it again during and after the First World War.

Twentieth-century clinical development

The overview reports that hypnosis developed alongside psychoanalysis and behavior therapy in the early and middle twentieth century, including use of imagination and relaxation in systematic desensitization. In the 1950s and 1960s the approach of Milton Erickson reintroduced the unconscious as a source of positive patient resources, while a 1969 work by Barber stressed social and cognitive factors. A 1995 meta-analysis by Kirsch is reported to have found that adding hypnosis to cognitive-behavioral therapy roughly doubled the effect size, a result the article says a 2021 update replicated.

The overview notes that Germany's Scientific Advisory Board for Psychotherapy recognized hypnotherapy as a method in 2006, that Austria has institutional recognition, and that insurance coverage varies by country. The sources reviewed for this page do not give dates for recognition of hypnosis by medical or dental associations, and none is asserted here.

The Division 30 definitions

Division 30 of the American Psychological Association, the Society of Psychological Hypnosis, publishes working definitions prepared by its Executive Committee in 2014. On its page, hypnosis is a state of consciousness involving focused attention and reduced peripheral awareness, characterized by an enhanced capacity for response to suggestion. A hypnotic induction is a procedure designed to induce hypnosis, and hypnotizability is an individual's ability to experience suggested alterations in physiology, sensations, emotions, thoughts or behavior during hypnosis. The Division describes the definitions as intentionally largely atheoretical.

The revised definition and the reasoning behind it were set out in a 2015 article in the International Journal of Clinical and Experimental Hypnosis, which describes the history, rationale and guidelines for developing it. Division 30 also uses the term hypnotherapy for the use of hypnosis to treat a medical or psychological condition or concern.

Clinical hypnosis as a professional label

The American Society of Clinical Hypnosis states that clinical hypnosis is used by licensed and trained doctors or master's-prepared individuals, including physicians, psychologists, dentists and other licensed clinicians such as nurses, social workers and marital and family therapists, who must practice within their training and licensing. The Society says it does not support hypnosis by people without health care training. In this sense the label refers to who delivers hypnosis and in what setting, not to a distinct form of hypnosis.

Reviews in anesthesia use the phrase therapeutic hypnosis for hypnosis offered alongside medical care. This page is a member of the Machipedia page Hypnotherapy, which covers the wider family, including hypnosis offered outside licensed healthcare roles; that material is not repeated here.

What a session involves in general terms

The sources reviewed describe hypnosis in general rather than procedural terms. By the Division 30 definitions, a session involves an induction, a procedure intended to produce the hypnotic state, followed by suggestions for changes in sensation, emotion, thought or behavior. The 2024 overview stresses that the therapeutic relationship remains essential and that hypnotizability is rarely measured in clinical studies. Scripts and induction wording are not described on this page.

The American Society of Clinical Hypnosis describes hypnosis as one tool that may be combined with other treatments, whose effect depends on the patient's motivation and the practitioner's training, and which can fail like any other clinical method. It adds that treatment length and cost vary and that many insurers cover only part of the cost, and only when a licensed professional provides the care.

Timing within medical care

In procedural medicine, trials differ in when hypnosis is used. A 2025 systematic review for anesthesia teams stratified its analyses by whether hypnosis was delivered before a procedure, during it or afterward, and found that timing changed which outcomes were affected. Hypnosis may also be combined with sedation or local anesthesia, or used alone, so reported results depend on the clinical context and cannot be carried from one setting to another.

Uses described by professional bodies

The American Society of Clinical Hypnosis describes clinical hypnosis as a tool with broad applications and says it can help people use more of their natural abilities and make change more quickly. The 2024 overview groups applications into psychotherapy, psychosomatics and medicine, and describes pain, surgery and procedures under local anesthesia as the best-studied medical areas.

Conditions covered by published reviews

A 2024 overview of 49 meta-analyses published between 2003 and 2022 organizes the literature by medical procedures, labor and childbirth, pain, cancer-related symptoms, irritable bowel syndrome, smoking cessation, obesity and mental or psychosomatic symptoms. These categories describe where hypnosis has been studied, and a topic's presence in this list does not mean the sources support a benefit for it. The sections below keep pain, procedures, anxiety and irritable bowel syndrome separate for that reason.

Overview of the review literature

A 2024 overview of 49 meta-analyses of randomized trials (261 distinct primary studies, with much overlap) reported effect sizes from -0.04 to 2.72. Few reviews reported certainty ratings, about two thirds of effects showed substantial heterogeneity, and 26 reviews were rated critically low on the AMSTAR 2 tool. The authors judged there is reasonable evidence for hypnosis, especially for medical procedures, pain and children, and called for head-to-head comparisons with established treatments. One author discloses membership of an Ericksonian society.

Pain

A 2026 systematic review included 106 randomized trials of hypnosis for clinical pain. A meta-analysis of 57 studies with 4,572 participants found lower post-intervention pain than with non-active controls (standardized mean difference -0.33), with no subgroup differences by pain type, control type or delivery mode. Hypnosis did not outperform active controls: -0.13 against relaxation (14 studies), -0.17 to -0.19 against pain education (7 studies) and -0.32 against cognitive-behavioral therapy (5 studies).

The authors describe the reductions as modest and comparable to other psychological interventions and say hypnosis should not be presented as a reliably superior pain treatment. Only the abstract was read for this page.

Procedures, surgery and anxiety

A 2025 systematic review in Anaesthesia identified 142 studies with 9,238 patients. Hypnosis before an intervention was associated with lower post-intervention pain (mean difference -0.88 cm on a visual analogue scale) and anxiety (standardized mean difference -0.76). Hypnosis during an intervention lowered pain during the procedure by 1.14 cm and was associated with lower risk of postoperative nausea and vomiting (risk ratio 0.43). Evidence on other outcomes was lacking, and the authors say the effect on most outcomes remains unknown.

A Cochrane review of interventions to increase acceptance of local anesthetic in children having dental treatment included 26 trials, one at low risk of bias. For hypnosis it found a single trial of 29 participants with less reported pain, rated very low certainty.

Irritable bowel syndrome

A 2025 network meta-analysis of behavioral therapies for irritable bowel syndrome included 67 trials with 7,441 participants. Versus a waiting list, gut-directed hypnotherapy (12 trials, 1,507 patients) was associated with less failure to improve global symptoms (relative risk 0.79, 95 percent confidence interval 0.66 to 0.95). The authors rated certainty low or very low, citing publication bias and risk of bias.

A separate 2025 review of 16 trials reports that 40 to 81 percent improved in abdominal symptoms and a pooled dropout of 8.0 percent across 12 studies; only its abstract was read. Results apply to this condition only.

Psychological conditions

The 2024 overview states that research on hypnosis in psychotherapy and psychosomatics remains limited and that hypnotizability is rarely measured. The sources read do not allow condition-by-condition conclusions for mental health problems.

Adverse events reported in trials

In the 49-review overview, only 8 reviews stated that no adverse events were reported, and 28 reviews contained no safety information. Where events were reported they were sparse: mild dizziness after a first session in one trial, one dropout after a panic attack during a session in another, and no significant differences in adverse events between hypnosis and control groups in trials in labor and childbirth. The authors call for systematic monitoring of harms in trials of behavioral interventions, so the absence of reported harm in the trials is not equivalent to evidence of safety. The Cochrane dental review found that no included trial reported adverse events.

Memory, regression and suggestion

A 2025 narrative review in Frontiers in Psychology states that research on hypnotic regression, which aims to recall early or repressed memories, is scarce and mainly anecdotal, and that the accuracy of recalled material is hard to verify. It reports that imagery and unintentional suggestion can lead to false memories, that hypnotic suggestion can inflate confidence in them, and that some studies attribute this to high hypnotizability and not to hypnosis itself, while others dispute that. Pre-hypnotic warnings may reduce false memories, though this is debated.

The authors advise caution with hypnotic regression and guided imagery, avoiding leading questions, and evaluating regression case by case. Practices that present hypnosis as retrieving past lives, such as Past Life Regression, are described on their own Machipedia pages; the sources reviewed here concern memory in clinical settings and make no claim about them.

Suitability and care boundaries

The sources reviewed do not set out a list of formal contraindications, and none is asserted here. They do state limits: hypnosis can fail, outcomes depend on the patient and practitioner, people with low hypnotizability generally do not benefit, and the 2026 pain review concludes that hypnosis offers modest, supportive effects and should not be presented as a reliably superior treatment. Hypnosis should not delay or replace necessary medical, dental or psychological care, which remains the responsibility of the treating clinician.

Training and professional registers

The American Society of Clinical Hypnosis runs a certification program for clinicians. Its page states that certified practitioners hold an advanced degree from an accredited institution, are licensed or certified to practice in their state or province, and complete peer-reviewed consultation, and that certification does not by itself establish competence.

In 2024 the American Psychological Association's Monitor reported that Division 30 was working on revised training standards with the Society for Clinical and Experimental Hypnosis, which runs its own certification program. No statutory training standard was sought; professional bodies' own programs are cited.