Hypnosis has been explored as a therapeutic intervention for anxiety and stress reduction (Valentine, Milling, Clark, & Moriarty, 2019) and the management of impulsive behaviours. Scientific studies have investigated its effects on cortisol levels—a biomarker for stress—and various forms of impulsivity, including eating behaviours and decision-making processes. Chronic stress is associated with elevated cortisol levels, which can lead to various health issues. While specific studies directly measuring the impact of hypnosis on cortisol levels are limited, hypnosis has been recognized for its potential in stress management (Fernandez et al., 2021, Schmidt et al., 2024).

Impulsivity, characterized by actions taken without forethought, is a trait linked to various behavioural issues, including overeating and substance abuse. Research indicates that hypnosis can play a role in mitigating impulsive behaviours. A randomized controlled trial assessed the impact of Ericksonian hypnosis combined with self-hypnosis training on eating disinhibition among adults with obesity and high impulsivity. Improvements in weight, BMI, and susceptibility to hunger were observed, suggesting that hypnosis can positively influence eating behaviours and contribute to weight loss (Lemyre, Sheeran, & Bélanger, 2022).

In summary, while direct evidence linking hypnosis to reduced cortisol levels is limited, its efficacy in stress reduction implies potential benefits for cortisol regulation. Moreover, empirical studies demonstrate that hypnosis can effectively reduce various forms of impulsivity, highlighting its promise as a therapeutic tool for managing stress and impulsive behaviours.

Inducing positive emotions in laboratory settings presents unique challenges compared to evoking negative emotions. While negative emotions are easily triggered using standardized methods like the International Affective Picture System (IAPS) or false feedback techniques (e.g. Schmidt, Warns, Hellmer, Ulrich, & Hewig, 2018), which reliably produce feelings of fear, sadness, or frustration, inducing positive emotions is less straightforward (Ekman & Davidson, 1994). Negative emotions are evolutionarily geared toward avoiding harm and addressing immediate survival threats, creating a potent and direct response pathway in the brain (LeDoux, 2000). In contrast, as articulated by Barbara Fredrickson’s Broaden-and-Build Theory, positive emotions serve a subtler function: they encourage exploration, creativity, and learning, ultimately building long-term resources such as resilience and healthy coping mechanisms (Fredrickson, 2004).

Hypnosis, however, emerges as a promising tool for evoking positive emotions in a controlled setting. Hypnosis typically begins with inducing relaxation, which naturally primes the brain for positive emotional experiences by reducing stress-related physiological arousal (Wark, 2008). Once relaxed, individuals are more receptive to positive suggestions, which can elicit emotions like joy, gratitude, and contentment—emotions often associated with healing and improved well-being (Hammond, 2010). Beyond transient mood enhancement, these positive emotions foster psychological growth and resilience, potentially leading to lasting improvements in emotional regulation and mental health. Thus, hypnosis facilitates the induction of positive emotions and amplifies their therapeutic benefits, providing a valuable resource for affective research and mental health treatment (Kirsch, 1994).

The induction of a “safe place” is a foundational technique in hypnosis, widely used to help clients achieve a state of calm and security, which is essential for progressing in therapeutic interventions. This approach involves guiding participants to imagine a place where they feel entirely safe, often a comforting or peaceful environment tailored to their preferences. The safe place induction is critical in building trust and lowering defensive barriers, particularly in treatments addressing trauma and anxiety. By creating an internalized sense of safety, clients can access deeper levels of relaxation, reducing physiological arousal associated with stress responses (Fernandez et al., 2021, Schmidt et al., 2024).

This technique serves as a preparatory phase for more intensive therapeutic work, such as trauma reprocessing or exposure to anxiety-provoking stimuli. It allows clients to return to this mental “safe place” whenever distress arises, fostering a sense of control and emotional stability that is invaluable in therapy (Hammond, 2010). Research also suggests that this safe place induction can enhance emotional regulation, a vital skill for individuals dealing with anxiety disorders or PTSD (Lang, Bradley, & Cuthbert, 2008).

Notably, the safe place induction aligns with principles of affective neuroscience by engaging brain regions associated with positive emotional processing, such as the prefrontal cortex, helping the client to anchor their experience in a positive, secure mental framework and reduce pain (Laureys, Maquet, & Faymonville, 2004). Overall, this induction is a powerful tool that supports clients in building a foundation of trust, which is crucial for the success of subsequent therapeutic interventions.

Hypnosis has emerged as a powerful method for stress reduction, showing both immediate and long-lasting effects on individuals’ ability to cope with stress. Recent research highlights how hypnosis, particularly through posthypnotic safety suggestions, can significantly enhance individuals’ resilience to stress by fostering an enduring sense of calm and security (Schmidt et al. 2024). These posthypnotic suggestions enable participants to activate feelings of safety even after hypnosis sessions, providing a self-regulatory tool for managing stress responses long-term. Schmidt and colleagues found that these suggestions help participants downregulate their physiological stress responses, enhancing the brain’s capacity to manage emotional and physical reactions to stress (Schmidt et al., 2024).

A central aspect of hypnosis for stress reduction is the “safe place” imagery technique, which allows participants to imagine themselves in a secure and comforting environment. This method provides immediate stress relief and enhances emotion regulation skills, creating a mental sanctuary that participants can return to whenever they feel overwhelmed. Research by (Karrasch, Bongartz, Behnke, Matits, & Kolassa, 2022) emphasizes that safe place induction helps people maintain emotional detachment from stressors, which can improve their ability to cope with anxiety-inducing situations over time. By helping individuals “step back” from their stress, safe place imagery facilitates a more grounded perspective, fostering resilience in everyday life and high-stress environments.

Additionally, imagining a safe place during hypnosis has aided in emotion regulation by detaching oneself from stressful events. Drujan, Fallgatter, and Fuhr (2023) explored the use of safe place imagery combined with detachment interventions, finding that participants experienced reduced stress levels and improved emotional resilience. These detachment interventions offer participants mental distance from their stressors, allowing them to regulate emotional responses more effectively. This approach is particularly helpful for individuals with chronic stress, as it promotes sustained stress relief through a manageable and self-directed technique (Drujan et al., 2023).

Furthermore, a systematic review by (Fisch, Brinkhaus, & Teut, 2017) concluded that hypnosis is effective in reducing perceived stress across a wide range of applications, from work-related stress to chronic anxiety. The review found that hypnosis sessions focusing on relaxation and self-regulation significantly reduced self-reported stress levels. Importantly, the benefits of hypnosis are not just immediate; they extend over the long term, as individuals who practice hypnosis and integrate these techniques into daily life report lasting improvements in their overall stress management capabilities (Fisch et al., 2017).

In conclusion, hypnosis provides a robust framework for stress reduction, leveraging techniques such as posthypnotic safety suggestions and safe place imagery to empower individuals in managing their stress responses. By cultivating a mental “haven,” participants learn to activate feelings of calm and security independently, extending the benefits of hypnosis well beyond the therapy session. Studies by (Schmidt et al., 2024, Karrasch et al., 2022, Drujan et al., 2023), and (Fisch et al., 2017) collectively illustrate how hypnosis not only reduces immediate stress but also builds lasting resilience, making it a valuable tool for enhancing mental health and emotional well-being.

Hypnotic suggestions designed to evoke feelings of safety are effective, as shown through participants’ subjective ratings of increased calmness, relaxation, and security. These experiences are self-reported and can be objectively measured through physiological responses in both the brain and body. Studies show that safe place suggestions during hypnosis can reduce heart rate and lower cortisol levels, indicating stress reduction. Neuroimaging techniques reveal activation in brain regions associated with positive emotional regulation, such as the prefrontal cortex, highlighting the tangible impact of safety-focused hypnosis on physiological and neurological markers of well-being.

The prefrontal cortex plays a pivotal role in processing and evaluating sensory input from other brain regions. Botvinick and Braver (2015) describe the prefrontal cortex as the “conductor” of the brain’s sensory orchestra, coordinating cognitive and affective control by integrating motivation, emotion, and goal-directed behaviour to guide adaptive responses. This region integrates and prioritizes information, determining which sensory signals require attention and which can be subdued. By regulating neural responses, the prefrontal cortex supports goal-directed behaviour, emotional regulation, and decision-making. It modulates inputs from the amygdala, which processes emotions like fear, and the sensory cortex, which handles perception. This orchestration allows us to focus, regulate impulses, and respond appropriately, ensuring a balanced “performance” where essential signals are highlighted while others are quieted (Dixon, Thiruchselvam, Todd, & Christoff, 2017). The prefrontal cortex comprises key functional networks crucial for cognition and behaviour. The Default Mode Network (DMN) supports self-referential thinking and memory (Raichle et al., 2001). The Central Executive Network (CEN), involving the dorsolateral PFC, manages working memory and decision-making (Seeley et al., 2007). The Salience Network (SN) detects relevant stimuli and switches between networks (Menon, 2011). The Limbic Network (orbitofrontal and ventromedial PFC) integrates emotion and reward (Rolls, 2004). The Frontoparietal Network (FPN) modulates attention and cognitive flexibility (Miller & Cohen, 2001). These networks enable adaptive behaviour, and dysfunction may underlie psychiatric disorders.

To illustrate the implications of hypnosis in the re-evaluation of sensory content, I refer to my first hypnosis EEG study that convinced me about the power of hypnotic suggestions. In this study, I had low, middle and high suggestible participants in two conditions: hypnosis and control. In every condition, they sat in the EEG chamber with the EEG cap on and looked at a big screen where we presented visual stimuli. The participants saw big symbols on the screen, one after the other. The symbols were bright colours: triangles, circles, and squares. Participants’ task was to count the number of squares that were the oddball stimuli, only occurring in 10 per cent of trials. Eyes were open the whole time. In the control condition, it was an easy task that all participants could perform. In the hypnosis condition, I induced a state of hypnosis and told participants that there was a wooden board in front of their eyes that blocked their vision on the screen Fig. 1A) illustrates the suggestion.

The results show that the typically occurring P3b response in the brain to the rare to-be-counted visual stimuli was drastically reduced in the hypnosis condition compared to the control condition. Participants’ counting performance was also significantly reduced. Participants reported that they did not see the stimuli in the hypnosis condition, so they could not count them. Interestingly, the early sensory evoked potentials like the N1 and the P2 amplitudes were unchanged, so the visual input entered the brain like in the control condition. However, the later P3b sensory evoked potentials were drastically reduced. Fig. 2 shows the results of the study. The results are in line with previous EEG-studies on a hypnosis-induced visual blockade by (De Pascalis, 1994; Spiegel & Barabasz, 1988; Spiegel, Cutcomb, Ren, & Pribram, 1985) and (Barabasz et al., 1999).

In a follow-up analysis, we examined how different brain areas worked together by measuring the timing and strength of connections between EEG electrodes representing frontal, parietal, and occipital brain regions. This analysis showed that, when processing target stimuli, there was a decrease in the flow of information from parietal regions (which handle attention) to frontal regions (which manage executive functions). Parietal brain regions, particularly the posterior parietal cortex, play a crucial role in attention by filtering, prioritizing, and directing focus toward relevant sensory information in the environment (Corbetta & Shulman, 2002). Certain forms of attention and executive control are implemented by the interactive coordination between specific frontal and parietal regions, where the prefrontal cortex helps with top-down control of attention and goal-directed behaviour, while the parietal cortex processes sensory input and directs attentional resources to relevant stimuli (Corbetta and Shulman, 2002, Miller and Cohen, 2001). This interaction allows for the flexible allocation of cognitive resources based on task demands and environmental cues. The findings of our study suggest that hypnotic suggestions creating a “visual block” may disrupt the usual coordination between frontal and parietal areas, which is important for top-down brain control (Franz, Schmidt, Hecht, Naumann, & Miltner, 2021). In two further studies, I did similar study designs in two further sensory domains: pain and auditory stimulation. In the hypnosis-pain study, we applied pain stimuli to participants’ hands and suggested during hypnosis that they have a numbing glove on their hand (Schmidt, 2022). In the hypnosis-audio study, we suggested that participants have earplugs so they cannot hear sounds. Participants had to press a button whenever they heard a rarely occurring sound. We found that the auditory P3 brain response to the rarely occurring sound was again drastically reduced in the hypnosis condition with suggested earplugs (Franz et al., 2020).

Transferred to how the feeling of being in a safe place manifests in our brain, the results suggest that processing initial sensory inputs can be drastically modified with hypnotic suggestions. We do not need a real safe place to feel safe; instead, we can use our imagination. Moreover, blocking disruptive external stimulation and creating an inner safe place is even easier during hypnosis.

Concerning other physiological responses in the body that show the effect of safe place suggestions, we can measure salivary cortisol that reacts to acute stress. We found that participants who associated feeling at a safe place during hypnosis with an eliciting stimulus, the Jena Safety Anchor, showed no significant cortisol increase in an acute stress task (Schmidt et al., 2024). The central principle of the Jena Safety Anchor approach involves inducing hypnosis to evoke a robust sense of safety, which is then anchored post-hypnotically. This process enables the transfer of the safety response to contexts outside the hypnotic state, facilitating its accessibility in everyday situations. Here you can read the part where the Jena Safety Anchor is established:

“Please slowly open your eyes now. That’s good. In front of you lies a blank white sheet of paper and a pencil. Please pick up the pencil now and write the letter S, for safety, on this paper. By writing this letter, the paper — which was previously neutral and white — takes on the meaning of the feeling of safety.

Imagine how, in the past, important information was carved into stone so it could last for all time, allowing anyone to read it at any moment. By writing the letter S on this sheet of paper, you are ensuring that every time you read this letter, you will once again feel this sense of safety, just as you do now.

To keep this feeling of safety even closer to you, fold the piece of paper and put it in your pocket. By placing it in your pocket, this feeling stays close to you. Later, when you read this piece of paper with the letter S and put it back in your pocket, you will instinctively feel the same sense of safety that you are feeling now.

If you like, you can close your eyes once again and immerse yourself deeply in this wonderful feeling of safety. With this note, you are now carrying the feeling of safety with you wherever you go.“.

This study used the Trier Social Stress Test (Kirschbaum, Pirke, & Hellhammer, 1993), which included a five-minute job interview and a five-minute math task in front of a jury. The jury is instructed to give no feedback and only answer in standardized sentences. This task is designed to elicit stress. It has been shown in numerous studies that undergoing the TSST elicits cortisol increases, and a responder criterion was established: If cortisol levels increase more than 1.5 nmol/l, the person is classified as a cortisol responder (Miller, Plessow, Kirschbaum, & Stalder, 2013). In our study, all 60 participants were cortisol non-responders. This observation is remarkable as the cortisol responder rate we normally observe in our laboratory is over 80 per cent (Blasberg et al., 2023, Blasberg et al., 2023). This note suggests that the 30-minute hypnosis session conducted just before the TSST may have reduced the physiological arousal of participants enough to prevent a typical cortisol response to the stress test. Additionally, the calming effect of the hypnosis session may have obscured the impact of the Jena Safety Anchor in the experimental group, resulting in no detectable difference in cortisol levels between groups. The posthypnotic safety suggestion primarily showed its effectiveness by significantly reducing participants’ subjective stress ratings and fewer negative thoughts. Since participants knew whether they belonged to the safety or control group, demand characteristics might have influenced these subjective ratings. We told participants in the consent form that there are two groups of participants: one is allowed to use the Jena Safety Anchor during the TSST, and the other is not. All participants received the hypnosis session with the Jena Safety Anchor, and we observed an absence of the usual cortisol increase in all participants. We conclude that the hypnosis session likely contributed to lower cortisol stress responses. The Jena Safety Anchor notably reduced subjective stress and negative thoughts immediately, with a particularly promising outcome seen in the significant reduction of negative thoughts one week after the TSST. Participants who used the Jena Safety Anchor continued to report fewer negative thoughts compared to those in the control group, indicating enhanced emotion regulation that may help prevent rumination and depressive thoughts following a stressful experience. This sustained decrease in negative thinking aligns with a key aspect of resilience—the ability to recover after acute stress—suggesting that fewer negative thoughts may serve as a marker of resilience (Fig. 3) shows the main results of the study.

To measure the effect of hypnotic suggestions on impulsive behaviour in general, we used a risk paradigm where participants could decide to play safe or risky. The monetary rewards could, therefore, vary and be smaller or greater. We investigated highly suggestible participants and let them play the gamble in two conditions. In the safety condition, participants could use a posthypnotic trigger associated with a feeling of safety that was installed during hypnosis. In the control condition, participants used a control trigger with no meaning. Participants wore an EEG cap during the whole experiment so we could analyze their brain responses. We found that participants’ brain responses showed smaller differences between smaller or greater monetary rewards when they used their safety trigger compared to the control condition. That indicates less reward sensitivity (Böhmer & Schmidt, 2022). This finding aligns with participants’ statements that they did not care any more about the monetary rewards when they were suggested to feel safe during hypnosis (Schmidt, Hoffmann, & Rasch, 2020).

Moreover, these suggestions have been linked to reductions in impulsive decision-making, as demonstrated in delay discounting studies, where hypnotic safety suggestions encouraged more deliberate and less reward-driven choices (Schmidt & Holroyd, 2021). In this paradigm, participants received immediate or delayed rewards that they only got six months afterwards. In the control condition, we saw that participants’ brain responses differentiated significantly between immediate and delayed rewards, preferring immediate rewards. In the hypnosis condition, where the same participants were suggested to feel safe, brain responses in the N2 time window did not differentiate between immediate and delayed rewards any more (Fig. 4) shows the brain responses in the two conditions.

Hypnotic suggestions can alter brain responses and behaviour towards less impulsive and more deliberate choices. Immediate rewards are not as important anymore, and it is easier to wait for delayed rewards.

One impressive example of reducing impulsive behaviour is to alter food preferences. The ongoing obesity epidemic suggests that traditional methods for promoting healthier diets are not enough, and strategies that rely primarily on restricting unhealthy foods have limited effectiveness. It is essential to focus on shaping food preferences directly to address this issue. However, food preferences are influenced by many factors and often become difficult to change in adulthood. Therefore, a recent study explored whether an interactive, age-appropriate fairytale could positively influence the food choices of preschool children. (Zahedi, Akalin, Lawrence, Baumann, & Sommer, 2024) demonstrated that exposure to positive food-related themes could shape food choices even in young children, suggesting that subtle, story-based interventions may influence preference formation in a lasting way. In this study, the authors used a fairy tale that promoted eating fruits and vegetables. They also designed a control tale. In both stories, a brother and sister start their first day of school and notice their famously colourful city has lost its sparkle. Together, they manage to save their city and bring the colours back. In the food story, the city’s painter, responsible for refreshing the colours each night, falls ill due to eating too much junk food and can no longer work. The children give him magical healthy vegetables, which restore his strength so he can resume his job. In the control story, however, the painter’s problem is that he used low-quality paint, which failed to restore the city’s colours. The children help by providing him with high-quality paint, allowing him to brighten the city again. During both stories, children participated interactively by discussing topics related to junk and healthy foods or paint and colours, depending on the story. The stories were the same in length, structure, and engagement, but the control story had no references to food.

Participants were offered a tray containing healthy (e.g., apple, banana, orange slices) and non-healthy items (e.g., cake slices, cookies) to test food preferences. Each child chose one item to eat. The items varied daily, with at least two healthy and two non-healthy options to keep the choices fresh. This setup allowed researchers to observe whether the story influenced the children’s choices, encouraging them to pick healthier foods. This study demonstrated that hearing a fairytale-like story about healthy food can influence children’s food choices for at least two weeks. Remarkably, the effect extended from fruits to vegetables and was consistent across two groups, showing surprising stability given the brief 20-minute storytelling session. This foundational work aligns with findings in adults, where hypnotic suggestions similarly impact food preferences by reinforcing healthy eating attitudes (Zahedi, Łuczak, & Sommer, 2020).

Building on this, Zahedi and colleagues conducted an online study on posthypnotic suggestions and found significant long-term effects on food preferences. Participants who received posthypnotic suggestions favouring healthy foods reported more consistent choices aligning with these suggestions, highlighting the persistence of hypnotic influence on dietary behaviour (Zahedi et al., 2024). This shift towards healthier preferences is supported by brain studies, indicating that hypnosis can modify event-related potentials associated with reward, which are crucial in food selection processes (Zahedi et al. 2020). The results revealed that attentional responses, as reflected in the P3 component, were modulated as anticipated—enhanced for low-calorie items like vegetables and fruits and diminished for high-calorie ones. Additionally, a general increase in the Late Positive Complex (LPC) amplitude was observed for both low- and high-calorie categories. This pattern suggests that participants were updating their internal models in response to both types of stimuli. Optimally, this could indicate that low-calorie items were becoming more appetitive while high-calorie items were viewed less favourably. However, this remains an interpretative insight rather than a definitive conclusion (Fig. 5) shows the results of the study.

Feeling safe in high-stress environments like the intensive care unit (ICU) is essential for patient well-being, especially those undergoing non-invasive ventilation. Hypnotic suggestions of safety have shown promising results in enhancing patient comfort in such settings. In a study, (Schmidt et al., 2021) explored the impact of therapeutic safety suggestions on ICU patients and found that these suggestions, delivered during hypnosis, could alleviate stress and anxiety, thereby improving overall well-being. This approach leverages the brain’s response to comforting and positive cues, enabling patients to feel secure even in a complex, high-tech environment like the ICU (Schmidt, Deffner, & Rosendahl, 2021). Fig. 6 shows the main findings of our study.

Furthermore, the perception of safety provided by hypnotic suggestions can counteract unintended negative effects that may arise from standard ICU communications, which can inadvertently cause nocebo effects. These nocebo effects occur when language and communication styles unintentionally heighten patient distress (Guiance et al., 2024). Positive, suggestive techniques in hypnosis can help mitigate these adverse impacts, facilitating a more supportive environment. These findings raise the question of the core underling mechanisms and the need to connect research in these basic and important clinical applications with relevant model development and model testing in the neuroscience of cognitive and affective self-regulation. This may be the challenge for emerging research.

Studies have also shown that listening to positive suggestions, even via pre-recorded audio, can support mental health outcomes in ICU survivors, suggesting broader applicability for hypnosis in critical care settings (Ozkan et al., 2023, Szilágyi et al., 2014). As (Kekecs, Nagy, & Varga, 2014) demonstrated, hypnosis techniques have shown potential in reducing postoperative side effects, highlighting their therapeutic value across various medical contexts. Therefore, hypnosis offers an innovative, non-invasive way to enhance safety perception, providing a psychological shield that fosters resilience and emotional stability in vulnerable ICU patients. In a study with 3–6-year-old children, we provided a hypnosis audio intervention before a standard surgery to reduce preoperative anxiety and postoperative discomfort (Schmidt et al., 2025). In another study, we used a hypnosis app with hypnosis audio recordings called “The Peaceful Birth” (“Die Friedliche Geburt”) to reduce stress in pregnant mothers before the birth of their child (Motz, Brückner, & Schmidt, 2025). These are examples for low-threshold hypnosis interventions that alleviate patient’s discomfort before medical interventions.

Research indicates that when using hypnosis to reduce stress and anxiety, suggestibility, as measured by the Harvard Group Scale of Hypnotic Susceptibility (HGSHS, Shor & Orne, 1962), is not a critical factor (e.g. Schmidt et al., 2024). Heightened stress and anxiety naturally increase suggestibility (Bryant, Guthrie, & Moulds, 2001), while motivation ensures hypnosis effectiveness (Orne, 1966). These aspects enhance the generalizability of results across diverse populations.

In affective neuroscience, the longevity of hypnosis effects is a topic of interest, particularly in relation to emotional regulation and brain activity. Studies suggest that hypnotic interventions can produce lasting changes in emotional responses by modulating neural pathways associated with stress, anxiety, and pain. While the immediate effects of hypnosis are often well-documented, research on long-term outcomes is still evolving. Evidence indicates that individuals can retain the emotional benefits of hypnosis, such as reduced anxiety and improved mood, over time. However, further studies are needed to understand the durability of these effects and their neural mechanisms in the brain better.

While compelling evidence supports the effectiveness of hypnotic suggestions, the precise mechanisms underlying these effects remain unclear, presenting a limitation of the findings discussed in this chapter. Nonetheless, hypnosis interventions offer valuable potential for enhancing self-control and emotional regulation, benefiting a wide range of individuals.

While preparing this work, the author used ChatGPT to improve readability. After using this tool, the author reviewed and edited the content as needed and took full responsibility for the publication’s content.