Introduction

I started studying psychology, counselling and hypnotherapy in an attempt to understand and seek solutions to the mental anguish and emotional suffering often experienced by myself and others.

For more than 10 years while training to be and practising as a professional hypnotherapist, I noticed the powerful effects inducing a deep state of somnambulistic trance (a form of altered state of consciousness), can have on facilitating emotional healing related to past traumatic incidents.

While in Peru in 2016, I attended a 10-day shamanic healing retreat and directly experienced the effects of natural plant-based psychedelics ayahuasca and huachuma for the first time in a traditional ceremonial context. Although intense, and at times challenging psychologically, emotionally and physically, similar to many others’ reports, I found the altered states of consciousness and mystical experiences induced by these potent “plant medicines” to be highly insightful, healing and transformative on multiple different levels, with positive effects enduring long beyond the ceremonies.

Over the past decades, most research into the therapeutic potential of psychedelics was curtailed due to many of these substances being categorised as illicit (Miller, 2017). However, more recently, a “psychedelics renaissance” (Lu, 2021), is taking place thanks to a resurgence of studies and collaborations around the world which are increasingly providing evidence of significant therapeutic potential in regard to mental health (Perkins et al., 2021; Siegel et al., 2021).

This literature review investigates associations between altered states of consciousness (ASC), more specifically those induced by natural, plant-based psychedelics such as psilocybin, huachuma and ayahuasca, and positive psychotherapeutic and clinical outcomes in relation to treating mental disorders linked to trauma.

Trauma

Trauma, in its various different forms, is a common experience that affects the majority of the population at one time or another (Copeland et al., 2007; McLaughlin et al., 2013). In fact, in Australia, as much as 75% of the adult population is estimated to have been involved in some form of traumatic incident at some stage during their life (Productivity Commission estimates using ABS 2009).

The DSM 5 defines trauma as experiencing, witnessing, or having knowledge of a loved one enduring a life-threatening event (APA, 2013). Traumatic events are often related to experiences such as accidents, injury, violence, natural disasters, or, anything perceived as unexpected, dramatic or shocking. People can experience trauma physically, mentally or as a combination of both, in a variety of ways (Phoenix Australia, 2019). Certain segments of the population are more likely to experience trauma, these include: the homeless; children and adolescents in foster/supervised care; refugees; households where domestic violence occurs; workers in high-stress occupations like emergency services and the military; and LGBTIQ+ communities (Bendall et al., 2018; Phoenix Australia, 2013). Over the past few years in Australia, the issue of trauma has likely been exacerbated due to the COVID-19 pandemic and its associated measures, as well as numerous extreme weather events such as bushfires and flooding.

Psychiatrist Bessel van der Kolk provides the following description of trauma and how it is commonly experienced:

Trauma is much more than a story about the past that explains why people are frightened, angry or out of control. Trauma is re-experienced in the present, not as a story, but as profoundly disturbing physical sensations and emotions that may not be consciously associated with memories of past trauma. (Bessell van der Kolk, 2014)

Research suggests that most people exposed to something “traumatic” are not normally affected in a negative way following the initial sensitising event (Lukaschek et al., 2013; Lancaster, Melka, & Rodriguez, 2009). However, some people, when exposed to situations not typically considered traumatic, like the ones indicated above, i.e. those deemed life-threatening or shocking, can still go on to develop problematic symptoms or reactions (Lancaster, Melka, Rodriguez, & Bryant, 2014; Anders, Frazier, & Shallcross, 2014; Mol et al., 2005; Scott & Stradling, 1994).

Childhood trauma as well as distress caused as a result of neglect, rejection and abandonment can have a significant impact on how somebody reacts to traumatic experiences.Childhood trauma as well as distress caused as a result of neglect, rejection and abandonment can have a significant impact on how somebody reacts to traumatic experiences. Drell, Siegel and Ganesbauer (1993) refer to symptoms commonly associated with trauma in infants. They propose that infants are particularly sensitive and vulnerable to sensory stimuli while at the same time lacking the mature cognitive ability to understand and interpret what is causing them distress. To illustrate this, adopted and fostered children are renowned for problematic behaviour related to past unresolved attachment issues and trauma experienced at a young age (Hughes, Burnell, & Archer, 2003).

Evidence shows that stress encountered in everyday situations, especially experienced over prolonged periods, can also affect the brain in a similar way to how trauma does (Lupien et. al., 2018; Chetty et al., 2014; Grimm et al., 2014).

Certain vulnerable people, like those who lack adequate social support or coping skills, may be impacted more than others in regards to how taxing persistent daily stress may negatively impact their brains. For some, the effects are not dissimilar to those who have experienced what is typically considered traumatic. In effect, whether something is perceived as traumatic depends on the person, along with their prior experiences, expectations, neurobiology, support network and default coping strategies (Wright, 2020).

Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a chronic complex mental health issue related to trauma. PTSD is characterised by fear, anxiety and memories persisting for more than three months after a traumatic incident is experienced. It can have negative long-term consequences not just for the person who experiences PTSD, but also for their family and community (Herra-Escobar, 2021). In Australia, it is estimated that as much as 12% of the population suffers from PTSD, with women around two times more likely of being at risk than men (ABS, 2008). Not surprisingly, people working in professions and high stress environments where they are regularly exposed to work-related traumatic situations are also significantly more at risk (Phoenix Australia, 2013). Indigenous Australians are disproportionally affected by PTSD as a result of experiencing both historic and current-day trauma related to being separated from family, lands, and cultural identity (AIHW, 2018; Bendall et al., 2018).

Diagnosis is often complicated because PTSD symptoms can be undetected under co-morbid conditions such as substance abuse, major depressive disorder, somatisation disorder, and other anxiety spectrum disorders (Johnson, 2009).

In terms of conventional treatments for PTSD, cognitive behavioural therapy (CBT) is the most commonly used psychotherapeutic/counselling approach (Mendes et. al., 2008). In regards to pharmacotherapy, evidence suggests that the following medications may be somewhat effective for treating PTSD symptoms: fluoxetine, paroxetine, sertraline and venlafaxine (Bernardy & Friedman, 2017).

Even though CBT has been extensively researched and used as a PTSD treatment for many decades, it has its limitations, which include high non-response and dropout rates of as much as 50% (Kar, 2011). Additionally, the mechanisms responsible for CBT’s relative effectiveness are currently not well understood by science (Kar, 2011). In terms of pharmaceutical treatments such as selective serotonin reuptake inhibitors (SSRIs) and similar medications mentioned above, the non-response rate can range from 20-40% (Green, 2013). Furthermore, reports from various authors suggest that around 33% of people who suffer from PTSD are resistant to all forms of conventional treatment (Green, 2013).

Impacts that Trauma has on Cognitive Function

The effects of trauma on cognitive function, the brain and body as a whole can be far-reaching and extensive. Post-traumatic stress disorder (PTSD) is a chronic psychiatric condition related to trauma and stress. PTSD symptoms and presentations include invasive thoughts and memories, hyperarousal, reexperiencing traumatic events, and negative effects on mood and cognition. Sufferers also often experience psychological and physiological comorbidities such as major depressive disorder (MDD), anxiety disorders, substance use disorder, type 2 diabetes, cardiovascular disease, inflammatory bowel disease, and chronic kidney disease which all are also associated with elevated oxidative stress (OXS) and sterile inflammation (INF) (Kelly et. al., 2022).

Neuropsychologist Donald Hebb (1949) famously stated that “cells that fire together, wire together” (Hebb, 1949). In effect, through repetition, the habitual pathways in the brain get strengthened over time. The more often something is thought, the more the neuronal constellation gets reinforced, hardwiring a type of “neurological rut” in the brain which can be difficult to break.

Further to this, another theory by Neuroscientist Karl Friston known as the free-energy principle proposes that the brain filters awareness by optimising predictability and stability, as well as reinforcing beliefs, expectations, and an implicit model of the world (Friston, 2010). This means that People perceive what they are predisposed to perceiving and whatever is subsequently perceived strengthens existing schema and in a rapid way. people perceive what they are predisposed to perceiving and whatever is subsequently perceived strengthens existing schema and in a rapid way (Kahneman, 2011). Although this unconscious process may seem intuitive, it is not always necessarily accurate (Harris, 2017). From an outsider’s perspective, the response may seem disproportionate or inappropriate.

In terms of how this all relates to trauma, imprints left from a traumatic incident can predispose a person to interpret any similar situations through an ingrained filter based on thoughts and emotions from the original sensitising experience. This leads to the effect of being repeatedly “emotionally triggered” which then feeds into the loop or “vicious cycle” that reinforces the problematic perceptions, beliefs, expectations, and behaviour (Harris, 2017).

When trauma is experienced at a young age, the effects can be particularly pronounced and have far-reaching negative consequences for a person later on in life (Perkins & Sarris, 2021). Schwarz and Perry (1994) describe a developmentally maladaptive, generalised activation of the alarm response in infants, which can lead to hypervigilance, avoidance or re-enactment behaviours.

In the long-term, the effects of trauma experienced as a baby or young child can lead to depression, dissociation, as well as eating, identity, and personality disorders (Hughes et. al., 2003), in addition to “physical health conditions, health risk behaviours, and alcohol and substance use disorders, as well as broader negative effects on well-being and life satisfaction” (Perkins & Sarris, 2021). These presentations often begin to become manifest during the challenging developmental transition into adolescence (Hughes et. al., 2003).

Altered States of Consciousness

Before discussing the concept of altered states of consciousness (ASC), it is important to first define what consciousness is. This can be complicated as consciousness can be considered from many varied perspectives, both subjective and objective, and is also inherently philosophical in nature. Kokoszka (2007, p. 1), offers a simplified definition which seeks to encompass 20 others cited by Baruss (1987) :

Consciousness is understood as a specific phenomenon, irreducible to any other more fundamental phenomenon. It may be descried as a phenomenon, an “intuition,” or a sense, which accompanies every aspect of our psychic activity. Self-consciousness, on the other hand, is understood as a purposeful reflection of one’s own psychic activity.

Using this as a reference point, Kokoszka, then states that “Altered states of consciousness are defined as ones which have a form or content different from states considered as usual.” (2007, p. 2)

From a neurophenomenological perspective, there are four primary modes of consciousness: deep sleep, dreaming, waking, and integrative. Each of these modes corresponds to systemic operations of the brain as a function of adapting to both the external and internal environments and serve to make sense of the extraordinary characteristics of altered consciousness (Winkelman, 2010).

Varying levels of the corresponding scientifically measurable electromagnetic brainwave frequencies relate to these different modes by which consciousness is experienced. Spiritual writings often refer to the unusual levels as “non-ordinary states of consciousness” (NOSC), whereas in scientific literature they are known as “altered states of consciousness” (ASC) (Shalit, 2012).

Arnold Ludwig first introduced the concept of altered states of consciousness in his 1966 book of the same name. He surmised the following as attributes of ASC: alterations in thinking, disturbed sense of time, loss of control, change in emotional expression, change in body image, perceptual distortions, change in the meaning or significance of things, a sense of ineffability, feelings of rejuvenation and hyper-suggestibility (Kokoszka, 2007).

For millennia, traditional cultures have made use of ASC in a variety of ways. Shamanism is an ancient practice present in numerous tribal societies around the world. It involves accessing ASC in order to not only facilitate healing but also to seek insights, guidance and wisdom. However, in more modern times with the rise of the allopathic medical model and science based on methodological reductionism, shamanic practices involving ASC have often been regarded as dissociative, hysterical, and even psychopathological (Winkelman, 2010). In recent decades though, the concept of using ASC as a viable and legitimate form of treatment has been taken more seriously and continues to be researched (Kokoszka, 2007; ).

Methods of Attaining Altered States of Consciousness

Altered states of consciousness basically constitute any non-ordinary mental state induced by either physiological, psychological, or pharmacological agents or mechanisms which provide an experience recognised as deviating from certain norms that people usually experience during alert waking consciousness. (Ludwig, 1966)

Common natural, and relatively easy ways of reaching ASC which most people can normally achieve unassisted include: meditation, breathing techniques, yoga, music, and dance. There is a rich history and tradition of these as recorded and practised in many cultures, religions, and ancient scriptures around the world.

Methods of inducing ASC for the purposes of treating mental health issues associated with trauma include:

Hypnosis

Hypnosis involves using language patterns, phrases and narratives that promote states of relaxation, concentration and focused attention in the client, an ASC otherwise known as hypnotic trance. While in this state, a hypnotherapist is then able to communicate directly with the client’s subconscious mind to facilitate treatment (Chapman, 2006).

Hypnosis became recognised as a credible form of psychotherapy when the American Psychological Association established Division 30 Society of Psychological Hypnosis leading to formalised research studies into its therapeutic potential (Pintar, & Lynn, 2008).

Natural Psychedelic/Hallucinogenic Substances

The term psychedelic means “mind manifesting” (Doblin, Hoffman, Dass, & Shulgin, 2014). When taken psychedelics can induce ASC providing the user with transcendent, religious, mystical or spiritual experiences.

Emerging evidence suggests that plant-based psychedelics, including psilocybin, huachuma and ayahuasca, may provide psychotherapeutic and clinical benefit in the treatment of trauma and other associated mental health-related disorders (Reiff et al., 2020; Perkins et al., 2021; Ruffell et al., 2021; Sarris et al., 2022; Raut et al., 2022).

The scope of this review is to primarily examine the therapeutic potential of ayahuasca. However, due to certain commonalities and the fact that they are also natural plant-based psychedelics that induce ASC, below are brief descriptions of psilocybin and huachuma before we focus more in-depth on ayahuasca.

Psilocybin

Psilocybin is a natural psychedelic compound contained in over 200 different species of fungi, sometimes referred to as “magic mushrooms” due to the hallucinogenic effects they induce when consumed. Psilocybin has been studied much more extensively and for longer compared to huachuma and ayahuasca, and has demonstrated significant therapeutic potential, especially in regard to depression and anxiety (Miller, 2017) Consequently, it has recently been granted “breakthrough therapy” status by the US Food and Drug Administration (Perkins et al., 2022), which means that it “may demonstrate substantial improvement on a clinically significant endpoint(s) over available therapies” (FDA, 2022).

Huachuma

Huachuma, Echinopsis pachanoi, also known as San Pedro, is a tall columnar cactus native to the Andes mountains of South America. It is related to peyote (Lophophora williamsii), another, shorter species of cactus primarily found in North America. They both contain the natural active ingredient mescaline, which is a psychoactive alkaloid used traditionally as a sacrament by indigenous people for spiritual ritual and healing ceremonies. One recent study reported that experiences of psychological insight from mescaline consumption were associated with increased odds of reporting improvement in depression, anxiety, and drug use disorders. (Agin-Liebes et al., 2021).

Ayahuasca

Originating from the Amazon basin, Ayahuasca is a ceremonial brew typically made from the Banisteriopsis caapi vine and leaves from the Psychotira viridis plant. The name originates from the Quechua words ‘Aya’-meaning soul or spirit-and ‘Waska’-meaning rope or vine (Santos et al. 2007). This combination contains the psychedelic 5-HT2A receptor N,N-dimethyltryptamine (DMT) from P. viridis, plus β-carboline alkaloids with monoamine-oxidase-inhibiting properties from B. caapi. Once taken the psychotropic properties bind and stimulate serotonin receptors in the brain (Carhart-Harris, Kaelen, & Nutt, 2014). This effect induces altered states of consciousness which can include hallucinogenic visions, introspection, as well as augmented emotions and recall of memories (Domínguez-Clavé et al., 2016; White & Luna, 2016; Harris, 2017; Wolff et al., 2019).

Similar to other psychedelics, ayahuasca behaves like a nonspecific catalyst which both reduces defences and enhances unconscious content making it more accessible and available. An ayahuasca ceremony can result in participants experiencing several positive effects including relieving depression or anxiety, resolving trauma, or overcoming addictions. However, the exact mechanisms responsible for the beneficial psychotherapeutic outcomes are currently not well understood (Harris, 2017; Ruffell et al., 2020).

In any case, current trends potentially offer a new paradigm in regard to how mental health issues are considered and treated in the future. Research on plant-based psychedelics such as ayahuasca and other entheogens such as peyote, ibogaine, and psilocybin mushrooms reflects an increasing interest in traditional medicine which bridges ancestral healing traditions and modern medical/psychiatric approaches (Rush et. al., 2021).

Impacts that Plant-Based Psychedelics have on Cognitive Function

Evidence suggests that entropy of brain activity is elevated in psychedelic states, along with greater brain criticality. Research has identified a neurological constellation called the default mode network (DMN) which is associated with the sense of self, also known as the ego. This DMN works with the temporal lobe, especially the hippocampus and parahippocampal structures to produce normal waking consciousness (Carhart-Harris,, 2018). Under the influence of plant-based psychedelics such as psilocybin and ayahuasca, the DMN gets suppressed, thus enabling the therapeutic potential (Harris, 2017; Palhano-Fontes et al., 2015). As the neuronal networks become disorganised, receive less blood flow, and desynchronise cortical activity, a sense of an “ego dissolution” or disintegration is experienced, an ASC often described as a transcendental state of awareness or mystical experience (Barrett & Griffiths, 2017).

The dissolution of the ego experience disrupts habitual thought and behaviour patterns and allows for the opportunity to rewire, reprogram and create new pathways in the brain (Carhart-Harris, 2018), known as neuroplasticity (Costandi 2016). Data from neuroimaging indicate that serotonergic psychedelics support the process of neuroplasticity (Carhart-Harris et. al. 2012).

A large international study surveying 8,629 ayahuasca users by Perkins et al., (2022) reported that the more times ayahuasca was taken by participants, the less likely or frequently it was that they would consume alcohol or other drugs. Additionally, the intensity of the subjective spiritual experience (ASC), the number of personal self-insights gained, and taking ayahuasca in a naturalistic setting were all also associated with lower substance use in some models (Perkins et al., 2022).

In a 2018 Brazilian study, findings suggested that ayahuasca taken in a traditional context has therapeutic potential for treating crack cocaine addiction. Participants reported that when taking ayahuasca they were able to connect with an ASC that helped them to resolve problems, heal traumas and reduce their drug usage. Furthermore, the ceremonies conducted in a group setting enhanced perceptions of spirituality and community acceptance, as well as improving self-esteem, boosting them positively both emotionally and socially (Cruz & Nappo, 2018).

Research conducted by Netzband et al. (2020), reported that after a 12-day traditional-style ayahuasca retreat, participants displayed significant reductions in neuroticism, which persisted until the 6-month follow up. High levels of neuroticism are associated with mental health-related issues, such as depression, anxiety, and obsessive-compulsive disorder (Netzband et al., 2020). The level of reported mystical experience (ASC) correlated to the observed reductions in neuroticism. Similarly, Weiss et al. (2021), also reported reduced levels of neuroticism when they examined changes in personality following shamanic ceremonial use of ayahuasca.

A study undertaken in 2018 evaluated the sub-acute and long-term effects of ayahuasca on well-being and cognitive thinking style. Results indicated that changes in effect, satisfaction with life, and mindfulness were significantly correlated to the level of ego dissolution experienced. Participant ratings for both depression and stress significantly decreased following the ceremony and endured for 4 weeks, further demonstrating the therapeutic potential of ayahuasca. (Uthaug et al., 2018).

Further research in 2020 supports Uthaug et al.’s findings by showing that participants experienced both improved mindfulness and cognitive flexibility (ability to shift perspective or approach in order to adapt to change in the environment) both immediately after, and in the “afterglow” period (within 24 hours) of an ayahuasca ceremony (Murphy-Beiner & Soar, 2020).

These more recent studies build on Solar et al.’s 2015 research that showed ayahuasca intake led to significant increases in mindfulness-related measures in the range of those normally observed after extensive mindfulness practice such as meditation.

Other recent studies also indicate that ayahuasca can assist in the treatment of mood disorders and is effective for improving depression and anxiety symptoms (Sarris et al., 2021; Sarris et al., 2021).

In addition to its direct cognitive function effects, the ayahuasca brew also possesses anti-inflammatory qualities (Galvão-Coelho et al., 2020). This can be particularly beneficial for supporting the treatment of major depression where inflammation plays a role in both reward processing, as well as reactivity to negative information (Galvão-Coelho et al., 2020; Galvão-Coelho et al., 2021).

Early evidence demonstrates the beneficial effects of psychedelics particularly in combination with psychotherapy for management of PTSD (Raut et al., 2022). Conventional evidence-based psychotherapeutic treatments for PTSD usually include an element of fear being experienced, these include prolonged exposure (flooding), cognitive restructuring, and eye movement desensitization and reprocessing (EMDR) therapy (Nielson & Megler, 2012).

Ayahuasca activates the hippocampus which can allow for the formation of implicit memories previously disrupted by trauma-inducing events. Whilst under the influence of ayahuasca, it is possible to change the reaction to memories similar to how exposure therapy and EMDR work.

Inserra (2018), theorises that “Ayahuasca creates a pattern of brain activity which is conducive to the recall and/or re-experiencing of traumatic memories, or memories that have a negative connotation”.

One recent study undertaken by Perkins et al., (2021), specifically looked at the influence of context and setting on the mental health and wellbeing outcomes of ayahuasca drinkers. It analysed data from a cross-sectional study of 6,877 ayahuasca users from more than 40 countries who had experience with ayahuasca in a range of contexts and recorded information relating to demographics, patterns and history of use, as well as the setting, and ritualistic practices involved. Results indicated that aspects of setting such as ceremonial practices and additional supports, and set such as individual motivations do have significant effects on ayahuasca users’ acute experiences, likelihood of experiencing difficulties with integration, and longer term wellbeing and mental health outcomes (Perkins et al., 2021).

Discussion

Although in its early stages, research to support the use of ayahuasca and other psychedelics for the legal treatment of mental health disorders related to trauma appears promising. However, continued research on the efficacy of psychedelics is warranted (Reiff et al., 2020; Perkins et al., 2021; Ruffell et al., 2021).

Even though research to date suggests that ayahuasca is safe and offers considerable therapeutic potential for mental health issues, there does still exist an element of risk, especially when considering set and setting involving inexperienced facilitators or those wanting to exploit the increased interest and popularity. (Nielsen et. al., 2021)

Conventional Western approaches to treating mental health disorders predominantly involve one-one sessions between therapist and client in clinical environments. Preliminary results from the research highlighted in this review seem to indicate that treatment undertaken in groups in a naturalistic setting involving some form of ceremony facilitated by a shaman (functioning as the equivalent of a therapist) plays a significant role in the healing process and in supporting beneficial outcomes (Harris, 2017; Netzband et al., 2020; Perkins et al., 2021; Ruffel et al., 2021). However, this may not always be a feasible option to undertake considering how current modern treatments function. Thus, more research is required to determine the extent to which set and setting plays a role and how it could best be accommodated by the current mental health system.

Studies specifically looking at the mechanisms which lead to ASC could also shed light on the safest, most efficient, effective and practical ways to induce ASC. Additionally, it would also be beneficial to research how psychotherapy/counselling could best be integrated into or adapted for this process in order to best support the client and promote successful treatment outcomes.

Conclusion

Trauma is a significant issue and a contributing factor to a number of mental health related issues. Although conventional treatments such as CBT have proven to be effective to a degree, they do not work for everybody and have their limitations. There appears to be a strong correlation between experiencing significant altered states of consciousness (ASC) and psychological resolution of trauma. Inducing ASC via plant-based psychedelics has been a key component of shamanic healing practices for millennia and offers insights into alternative approaches for treating chronic and complex mental health issues. Although up until recently research into the psychotherapeutic potential of natural psychedelics such as ayahuasca has been limited, recent studies strongly suggest that these ASC-inducing substances in combination with appropriate setting considerations and psychotherapeutic support could potentially revolutionise the way we treat trauma.

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