Long regarded as a mysterious and sometimes controversial phenomenon, hypnosis has become increasingly accepted in clinical and therapeutic contexts. Its effects and abilities span a wide range of human experience, from perception and memory to emotional well-being and physical health. Although not all claims are equally substantiated, scientific studies, clinical literature, and therapeutic practice all provide enough evidence for appreciating the scope and validity of hypnosis.

1.  A Brief History of the Evolution of Hypnosis

The origins of hypnosis can be traced to ancient civilizations that employed trance-like states for healing purposes. In ancient Egypt, sleep temples, also known as dream temples, served as centres for healing. Patients would enter these unlit chambers to sleep, during which priests would induce trance-like states through chanting and other rituals. The interpretation of dreams during these sessions was integral to the therapeutic process. Similarly, in ancient Greece, Asclepian temples were established in honour of Asclepius, the god of medicine. These temples utilized a practice known as incubation, where individuals would sleep in the temple with the hope of receiving healing dreams. The focus was on the belief that divine intervention through dreams could lead to cures.

The modern history of hypnosis began in the 18th century with the work of Franz Anton Mesmer, an Austrian physician. Mesmer introduced the concept of "animal magnetism," proposing that an invisible fluid existed within the body and that imbalances in this fluid could lead to illness. He believed that he could manipulate this fluid to restore health—a practice he termed mesmerism. Mesmer's theories gained popularity, but they were met with scepticism from the scientific community. In 1784, King Louis XVI of France appointed a commission, including notable figures such as Benjamin Franklin and chemist Antoine Lavoisier, to investigate mesmerism. The commission concluded that the effects attributed to mesmerism were due to the imagination of the subjects, not any magnetic fluid. Despite this, mesmerism continued to influence subsequent developments in the field.

In the early 19th century, Scottish surgeon James Braid critically examined Mesmer's theories. Through his research, Braid discovered that individuals could enter a trance-like state through focused attention, such as gazing at a fixed point. In 1843, he coined the term “hypnotism” from the Greek word hypnos, meaning sleep, to describe this phenomenon. Braid emphasized that hypnosis was a psychological state—not a mystical or magnetic one—and he developed techniques for inducing and utilizing hypnosis therapeutically. In the latter half of the 19th century, French physician Ambroise-Auguste Liébeault, along with his colleague Hippolyte Bernheim, founded the Nancy School of Hypnosis. They proposed that hypnosis was a normal psychological phenomenon and that suggestion could be used to treat various ailments. Liébeault's work laid the foundation for modern hypnotherapy by emphasizing the power of suggestion and the mind-body connection.

The 20th century saw hypnosis gain acceptance as a therapeutic tool. During World War I, hypnosis was employed to treat soldiers suffering from shell shock, now recognized as post-traumatic stress disorder (PTSD). This application demonstrated the potential of hypnosis in addressing psychological trauma. In the 1930s, American psychologist Clark Hull conducted rigorous scientific research on hypnosis, culminating in his book Hypnosis and Suggestibility (1933). In the 1940s and 1950s, Dave Elman developed rapid induction techniques and applied hypnosis extensively in medical and dental settings. His 1964 book, Hypnotherapy, became a foundational text for practitioners. Simultaneously, Milton H. Erickson pioneered Ericksonian hypnosis, introducing indirect suggestion, metaphor, and storytelling as therapeutic tools.

In recent decades, hypnosis has been integrated into various therapeutic modalities. For instance, cognitive-behavioural therapy (CBT) has incorporated hypnotic techniques to treat conditions such as phobias, addictions, and anxiety disorders. This integration, known as cognitive hypnotherapy, combines conscious cognitive strategies with subconscious reprogramming to offer deeper and more lasting results. Indeed, advancements in neuroscience have provided empirical support for hypnosis. Specifically, brain imaging studies have shown that hypnosis can alter brain activity, thus supporting pain management, stress reduction, and the treatment of various psychological conditions.

2. Different Styles of Hypnosis

Hypnosis is not a single, uniform technique but a flexible practice with a range of styles suited to different goals, subjects, and contexts. From the brisk, dramatic inductions used in stage performances to the slow, gentle approaches employed in deep therapeutic work, these varying styles differ not only in method, but also in how the hypnotic state is accessed, the depth of trance achieved, and what outcomes can realistically be expected.

Stage hypnosis: Sensory overload/confusion induction

One of the most immediate and dramatic forms of hypnosis is through sensory overload or confusion induction. Often seen in stage hypnosis or rapid therapeutic interventions, this method typically takes only a few seconds to under a minute. It works by overwhelming or disrupting the conscious mind—commonly referred to as the critical faculty—through rapid verbal or physical input. Techniques such as sudden hand drops, misdirection, startling verbal commands, or breaking expected patterns can cause a momentary "short-circuit" in the analytical mind. In this brief opening, a suggestion may be implanted before conscious awareness reasserts itself.

The trance achieved through this method is usually light to medium in depth, suitable for immediate compliance with simple suggestions like "you are stuck to the chair." However, it is not ideal for deeper therapeutic work, introspection, or long-term change, as the hypnotically achieved trance state tends to be short-lived unless intentionally deepened. This type of quick, within-seconds induction is most effective in three contexts: entertainment settings like stage or street hypnosis; emergency situations where fast therapeutic action is needed (such as acute pain); and with highly suggestible or preconditioned individuals.

Directive hypnosis: Clinical hypnotherapy

A more structured and traditional approach to hypnosis is clinical hypnotherapy. This involves using clear, direct commands to guide the patient into a trance state that typically lasts 1–5 minutes. For instance, a clinical hypnotherapist may use straightforward instructions such as “Close your eyes, relax your body, and focus on my voice,” employ countdowns, or focus the patient's attention on their breathing or a visual point. This style assumes a degree of compliance and works efficiently within a structured framework. The depth of trance achieved is usually medium, though skilled practitioners can reach deeper states.

Directive hypnosis is particularly effective for behavioural change goals such as smoking cessation, habit reversal, or procedural applications like pain management. It also supports ego strengthening and performance enhancement. However, it may not be as effective with highly analytical or resistant individuals (who show higher beta activity), and its structured nature may cause the depth of trance to plateau unless supplemented with more creative or permissive techniques. This approach is well suited for clients who respond well to structure, those in time-limited sessions, or situations where deep insight is not required, such as phobia treatment or sports hypnosis.

Permissive hypnosis: Lulling into trance

At the other end of the spectrum is the permissive or lulling style of hypnosis. This method is typically used in deep therapeutic work, including trauma processing, regression therapy, or existential exploration. Sessions using this style often take ten minutes or longer, employing gentle, rhythmic, and indirect language to gradually bypass the critical mind. Techniques include progressive muscle relaxation, guided visualisation (such as imagining a peaceful walk or descending a staircase), and metaphorical storytelling, often drawing from Ericksonian traditions. Rather than commanding a state, this approach offers space for the subject’s internal experience to unfold naturally. For example, instead of saying “You are now relaxed,” the hypnotist might say, “You may notice a sense of ease beginning to spread.” This subtle, permissive style facilitates access to deep trance states, often reaching somnambulistic levels where unconscious material can surface and be integrated. It is particularly effective for uncovering the root causes of psychological patterns, engaging the imagination in problem-solving, and providing a deeply safe space for emotional processing. However, it is time-intensive and may not be suitable for individuals seeking rapid results or those who prefer a more structured approach.

Summary Table

The depth of the trance state does influence what can be achieved with the corresponding style of hypnosis. For example, light trance is enough for pain relief, habit change, and ego strengthening. Medium trance is useful for emotional release and desensitisation. Deep trance (somnambulism or Esdaile state) is reported to enable profound anaesthesia, age regression, and hallucinatory phenomena. The Esdaile state, particularly, involves a very deep trance, to the point that you can perform surgery on people without them noticing. Responsiveness to suggestion often determines the depth of trance level that one may experience.

3. Hypnotisability, Size of the Corpus Callosum, and Brainwave Frequencies

The corpus callosum is the thick band of nerve fibres connecting the left and right hemispheres of the brain, allowing communication between them. Several neuroimaging studies (e.g., using MRI) have shown that highly hypnotizable individuals tend to have a larger anterior corpus callosum. Case in point, one prominent study by Horton et al. (2004, NeuroImage) found that highly hypnotizable people showed greater structural integrity and volume in the rostrum and genu of the corpus callosum—regions involved in frontal lobe connectivity. This suggests that these individuals may exhibit greater hemispheric integration, allowing for a fluid shift between analytic and imaginative modes of processing. The enhanced interhemispheric communication might support greater dissociation, imagination, and absorption—key traits associated with hypnotizability. It may also allow the critical faculty (left hemisphere) to loosen its dominance, allowing imaginative right-hemisphere processes to guide experience more freely. Thus, the individual becomes so absorbed in their internal experiences and fantasies that they relegate the experiences of their immediate external environment to the subconscious mind.

Apart from the size of the corpus callosum, the level of hypnosis one reaches is also determined by the frequency range of one's brainwaves:

High hypnotizables often show increased theta activity during trance, especially in the frontal and central midline regions. Theta is associated with imagination, memory, and deep absorption—hallmarks of the hypnotic state. Alpha activity also increases in early trance or relaxation stages, particularly in medium-hypnotizable individuals. By contrast, low hypnotizables tend to retain higher beta activity, which reflects cognitive vigilance and resistance to trance.

4. Self-Hypnosis vs. Trance vs. Meditation

“Trance” is a general term for altered states of consciousness characterized by deep focus, reduced awareness of the external world, and increased internal awareness. A light trance state can occur even naturally (e.g., during driving or daydreaming). However, deeper trance states, such as during guided hypnosis, intense dancing, or shamanic rituals, involve a more significant dissociation of consciousness. Thus, both meditation and self-hypnosis are modes of entering a trance state, but with different results.

On the one hand, self-hypnosis is a self-induced, focused state of attention used to influence the subconscious mind, usually with a specific goal (e.g., habit change, pain management). It primarily involves suggestion (often scripted or memorized affirmations) to access the subconscious. Also, self-hypnosis may involve induction techniques to reach the trance state (e.g., counting down, body scans). Thus, when engaging in self-hypnosis, one is usually goal-focused and generally conscious of the process.

On the other hand, meditation is a mental practice of focusing attention or awareness, often to cultivate mindfulness, concentration, or a sense of presence. It can be passive (mindfulness, open awareness) or active (concentration on breath or repeating a mantra). One often engages in meditation with the goal of developing calmness, insights or spiritual growth. Due to the need to centre one's awareness during meditation, you are typically more alert and observant than in self-hypnosis.

In a 2016 paper, Lush, Naish, and Dienes report finding that “meditators score lower on hypnotisability scales than non-meditators and that highly hypnotisable people score lower on trait mindfulness scales than low hypnotisables.” On the basis of this finding, the scholars posit that “hypnotic response and meditation involve opposite processes.” The following is a diagram from their paper depicting the vast difference between high hypnotizables and meditators in the time they took to judge their intentions.

5. Summary of Claimed Effects and Abilities of Hypnosis

This section summarizes some of the claimed effects and abilities attributed to hypnosis. These claims fall into five categories—cognitive impacts; emotional and physiological benefits; pain management; behavioural changes; and posthypnotic effects.

Cognitive Impacts

One of the central features of hypnosis is increased suggestibility, that is, a heightened openness to accepting and responding to suggestions. This trait is strongly supported by research and is considered a cornerstone of the hypnotic state. Another well-documented cognitive effect is an altered perception or reality, where one may experience hallucinations, distorted sensory input, or the inability to perceive certain body parts. Enhanced focus and concentration could also be the case, with some claims of subjects demonstrating sustained attention that surpasses their normal capabilities. However, the evidence here is somewhat context-dependent.

Emotional and Psychological Benefits

Hypnosis is widely used to reduce stress and anxiety, often demonstrating comparable efficacy to CBT or relaxation techniques. Similarly, it plays a role in trauma processing, especially when used carefully within a broader therapeutic framework. Other emotional benefits include improved mood, with some individuals reporting a general uplift in emotional state, greater confidence, and decreased depressive symptoms. Hypnosis is particularly effective in the treatment of phobias, especially when combined with exposure-based therapies. Furthermore, it is used to enhance motivation and self-esteem, although outcomes in this area vary significantly depending on the individual's personality and the depth of the hypnotic state.

Pain Management

Hypnosis has also demonstrated strong efficacy in pain management, including applications in chronic pain conditions, surgical procedures without anaesthesia, and childbirth. It also shows moderate support in influencing autonomic nervous system responses, such as lowering blood pressure or heart rate, and altering skin temperature. One well-established application is in the treatment of irritable bowel syndrome (IBS). Gut-directed hypnotherapy protocols have been validated in multiple clinical trials and show strong support. For example, the Manchester Protocol involves using imagery and metaphors related to the gut to help patients manage their symptoms.

Behavioural Changes

Regarding behavioural changes, hypnosis has shown moderate to strong efficacy in smoking cessation, although results vary based on the individual and the specific protocol used. Weight loss through hypnosis is moderately supported, particularly when integrated with lifestyle and behavioural changes. Hypnosis has also been found to help with sleep improvement, aiding in the reduction of insomnia and improving overall sleep quality. It is commonly used for addressing tics and habitual behaviours such as nail-biting or stuttering, especially in children or highly suggestible adults, with moderate levels of success.

Posthypnotic Effects

Finally, posthypnotic suggestions, where instructions given during trance are carried out after the session ends, are strongly supported and widely used in therapeutic practice. These can be simple behavioural prompts or complex psychological anchors. Anchoring emotional or mental states to specific cues—like a gesture or word—can help a client access desired states more easily in daily life.

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https://www.verywellmind.com/what-is-hypnosis-2795921 

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