What this is
- This scoping review examines how mystical-type experiences during psychedelic therapy relate to mood outcomes in different clinical populations.
- It compares patients with life-threatening diseases to those with depression, focusing on their responses to psychedelics.
- The review synthesizes findings from 13 clinical trials, assessing the prevalence of positive outcomes linked to mystical experiences.
Essence
- Mystical-type experiences during psychedelic therapy are commonly associated with reduced anxiety and depression symptoms in both life-threatening disease and depressive populations. However, the strength of this relationship may depend on various factors including timing and therapeutic context.
Key takeaways
- 69% of the included studies reported a positive relationship between mystical-type experiences and improvements in mood symptoms. This finding was consistent across both life-threatening disease (80%) and depressive populations (63%).
- Psychedelic therapy in life-threatening disease populations showed no major differences in the frequency of positive outcomes linked to mystical experiences compared to depressive populations.
- The timing of symptom assessments varied across studies, which may influence the perceived relationship between mystical-type experiences and treatment outcomes.
Caveats
- The review's findings are limited by the unequal number of studies representing life-threatening disease populations compared to depressive populations, which may obscure potential differences.
- Statistical comparisons between the populations were not conducted due to the scoping review nature, limiting the ability to draw definitive conclusions.
Definitions
- mystical-type experience: A profound psychological experience characterized by feelings of unity, sacredness, and transcendence, often assessed in psychedelic therapy.
Simplified
Introduction
Psychedelic drugs are increasingly being studied for the treatment of various psychiatric disorders, including major depressive disorder (MDD),1–3 substance use disorders,4,5 and end-of-life anxiety and depression.6,7 While various theories highlight the importance of different aspects of the psychedelic experience in driving clinical outcomes, the exact mechanisms behind their therapeutic effects remain largely unknown. Some believe that the subjective effects of psychedelics are an important and even necessary factor in facilitating positive outcomes,8 although this remains a topic of debate in the field.9
This debate becomes more complicated when we consider the differences in how psychedelics are defined and categorized. Generally, psychedelics are a class of drugs that produce alterations in perception, mood, and cognition.10 “Classical,” or serotonergic, psychedelics have a common mechanism of action and are agonists or partial agonists of serotonin 2A receptors (5-HT2A-R).10 This classification includes drugs such as psilocybin, lysergic acid diethylamide (LSD), mescaline, and N,N-dimethyltryptamine (DMT). However, other compounds with different pharmacology that produce profound alterations in perception are often also categorized as psychedelics. This includes dissociative anesthetics such as ketamine, stimulant-empathogen drugs such as 3,4-methylenedioxymethamphetamine (MDMA), and atypical psychedelics like ibogaine. In this review, we focus on the subjective effects associated with a broad range of substances commonly referred to as psychedelics, including both classical and non-classical psychedelics.
Among the various subjective effects associated with psychedelics, one that has gained significant attention in clinical trials is the mystical-type experience. Common conceptualizations of mystical-type experiences are largely based on philosopher Walter Stace’s work, who claimed that all mystical experiences have certain common features, including a sense of unity, sacredness, noetic quality, deeply felt positive mood, ineffability, paradoxicality, and transcendence of time and space.11 In clinical trials investigating psychedelics, researchers use questionnaires to quantify these aspects of mystical-type experiences. The Mystical Experiences Questionnaire (MEQ) is the most frequently used tool in modern psychedelic research, originally developed by Griffiths and colleagues.12 While the original 43-item MEQ is scored into seven factors corresponding to Stace’s dimensions of mystical experiences, the revised 30-item MEQ (MEQ-30) condenses these into four core factors: mystical aspects (including internal unity, external unity, noetic quality, and sacredness), positive mood, transcendence of time and space, and ineffability.13 The MEQ-30 has been validated using data from controlled studies administering psilocybin. Other tools used to assess mystical-type experiences include the oceanic boundlessness subscale of the 5-Dimensional Altered States of Consciousness questionnaire (5D-ASC) and the Ego Dissolution Inventory (EDI).14
These measures are especially relevant in psychedelic-assisted therapy, where mystical-type experiences are proposed to be associated with improvements in clinical outcomes. For example, in patients with tobacco use disorder, scores on the MEQ correlated with abstinence and reductions in cravings.15 Similarly, in patients with MDD, scores on the MEQ had a significant and moderate correlation to decreases in depression scores.2 One area where these findings have garnered particular attention is in the treatment of depression and anxiety in patients facing life-threatening diagnoses such as cancer.6,7 Depression and anxiety disorders are common in this patient population, and are linked with poor outcomes, including reduced quality of life, lower treatment adherence, and decreased survival rates.16,17 Historical studies on the use of LSD to alleviate emotional distress in cancer patients18 may have influenced the resurgence of modern psychedelic-assisted therapy in populations with a life-threatening disease (LTD). Notably, several modern trials have found that mystical-type experiences induced by serotonergic psychedelics, including psilocybin and LSD, play a mediating role in reducing depression and anxiety in this population.6,7,19
Previous reviews have investigated the relationship between mystical-type experiences induced by psychedelics and various outcomes–for example, improvements in well-being and mental health,20 and symptom reduction in various mental health disorders.21 While the literature presents some mixed findings, many studies found a positive relationship between mystical-type experiences and increases in well-being and mental health.20 However, most studies reporting this association were conducted in healthy populations, raising the question of whether mystical-type experiences are necessary for observing improvements in symptoms in clinical populations. Although a review conducted in clinical populations found that the majority of studies report a positive correlation between mystical-type experiences and symptom improvement, half of the included studies were open-label, creating a high potential for biased results.21 The inclusion of more randomized, placebo-controlled trials, in addition to open-label trials, is imperative for drawing conclusions about the importance of these experiences in clinical populations. Moreover, the existing literature lacks a comprehensive review aimed at understanding the differences in how mystical-type experiences might impact treatment outcomes in specific clinical populations.
Although mystical-type experiences might serve as a common mediator of positive treatment outcomes across clinical populations, it is imperative to investigate whether specific features of these experiences are more relevant to certain diagnoses. At present, whether mystical-type experiences function similarly across different populations, or whether they are more strongly linked to symptom improvements in specific patient cohorts, is unknown. LTD patients facing depression and anxiety may process these experiences differently from individuals diagnosed with depression or anxiety disorders, given the unique psychological and existential challenges associated with terminal illness.22 In cancer patients, the occurrence of psychedelic-induced mystical-type experiences has been shown to facilitate a reconciliation between illness, mortality, and the meaning of life, as well as to promote a softening of rigid psychological patterns and the burden of their diagnosis.23 Importantly, the study reporting this23 did not formally measure mystical-type experiences, but qualitatively analyzed participants’ narratives from a psilocybin RCT reported by Ross et al.7 In this context, psychedelic therapy may lead to unique experiences in LTD populations by allowing patients to face their diagnosis and possibly find new meaning in their lives, enabling an acceptance of mortality without overwhelming fear, anxiety, and depression. On the other hand, mystical-type experiences may have different features and implications in people who are not faced with a terminal diagnosis, but who suffer from depression and anxiety. By exploring how psychedelic-induced mystical-type experiences are associated with therapeutic outcomes in individuals experiencing distress due to a life-threatening disease and in other clinical populations with anxiety and depression, this review maps the characteristics and reported mood effects of these experiences across different populations. Identifying potential differences in how mystical-type experiences relate to relief from anxiety and depression may help inform future hypotheses about the mechanisms through which psychedelic therapies exert their therapeutic effects, and whether different clinical approaches may be warranted depending on the nature of the anxiety and/or depression.
This scoping review focuses on the relationship between mystical-type experiences induced by psychedelics as they relate to anxiety and depression outcomes, comparing LTD populations with other clinical populations. Given the variability seen in naturalistic and observational studies, we have chosen to limit this review specifically to clinical studies administering controlled doses of psychedelics and measuring the occurrence of mystical-type experiences.
Methods
The scoping review followed an established framework24 with updated methodological guidance.25 The completed Preferred Reporting Items for Systematic Review and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guideline (Supplemental Material↗)26 tracked the reporting of key elements of the review process (Figure 1).
Preferred reporting items for systematic reviews and meta-analysis (extension modified for scoping reviews) diagram of the search strategy.
Stage 1: Identifying the research question
The research question guiding this review is: What is the relationship between mystical-type experiences and anxiety and depression treatment outcomes in life-threatening disease populations compared with other clinical populations?
Stage 2: Identifying relevant studies
APA PsycINFO, Embase, and PubMed were searched from any publication date to July 24, 2024. The three search concepts included were: mystical-type experiences, psychedelics, and mood symptoms. The search was conducted in all fields and multipurpose, with “AND” used to link the three concepts.
Stage 3: Study selection
The included studies recruited adult participants (age ⩾ 18 years) who experienced symptoms of anxiety and/or depression or were clinically diagnosed with anxiety and/or depression. Interventions administered were those that used any type of psychedelics, including psilocybin, LSD, ayahuasca, DMT, MDMA, mescaline, and ibogaine within a clinical context (e.g., research center and hospital). Only full-text clinical trials published in English in peer-reviewed journals were included. Gray literature, conference abstracts, poster presentations, and dissertations were excluded. Naturalistic studies were excluded, as were those including a healthy population.
Results from each database search were exported and uploaded into Covidence for data management and data screening. Duplicates were removed through Covidence. Three members of the research team independently screened the titles and abstracts of all the imported studies. Articles that fulfilled the study selection criteria were included in the full-text review phase. The search strategy produced 731 records, and 13 clinical trials were included in the scoping review (see Figure 1).
Stage 4: Charting the data
Data were extracted by three members of the study team—Member 1, Member 2, and Member 3 using a data extraction form developed by Member 1 and revised by Member 2 and Member 3. The data extraction form included the following key variables: author, year of publication, study design, type of psychedelic, participants’ mental health clinical indication(s), mood symptom measures, mystical-type experience measures, and type of relationship between mood symptom(s) and mystical-type experiences. Discrepancies were resolved through discussion with Members 1–3.
Stage 5: Collating, summarizing, and reporting the results
Data related to study characteristics, population details, intervention details, and outcomes were extracted (see Table 1). Results were summarized using quantitative descriptors and further interpreted in relation to existing literature in the discussion.
| Paper | Study design | Clinical population | Sample size | Type of psychedelic | Dose | Therapy (Y/N) | Mood symptom measures | Mystical-type experience measures | Outcome |
|---|---|---|---|---|---|---|---|---|---|
| End-of-life populations | |||||||||
| Ross et al., 2016 | Randomized controlled trial | Cancer-related anxiety diagnosis and depression | 29 | Psilocybin | 0.3 mg/kg (oral) | Y | HADS-A, STAI, HADS-D, BDI | MEQ30 | Reductions in anxiety (measured by STAI and HADS-A) and depression symptoms (measured by HADS-D and BDI) correlated with higher mystical-type experience scores (measured by MEQ) |
| Agin-Liebes et al., 2020 (follow-up to Ross et al., 2016) | Long-term within-subject follow-up observational design | Cancer-related symptoms or diagnosis of anxiety and depression | 14/29 above participants | Psilocybin | N/A | HADS, STAI, BDI | MEQ-30 | No relationship between changes in depression (measured by BDI, HADS) or anxiety (measured by STAI, HADS) and mystical-type experience scores (measured by MEQ) | |
| Griffiths et al., 2016 | Randomized controlled trial | Cancer patients with symptoms or diagnosis of depression and/or anxiety | 56 | Psilocybin | 22 or 30 mg/70 kg (oral)—two sessions, counterbalanced | Y | HADS, HAM-A, STAI, GRID-HAMD-17, BDI | 5D-ASC, Mysticism Scale (nine-points), HRS, MEQ30 | Decreases in depression (measured by GRID-HAMD, BDI, HADS-D) and anxiety (measured by HAM-A, STAI-Trait, HADS-A) correlated with higher mystical-type experience scores (measured by MEQ) |
| Holze et al., 2023 | Randomized controlled trial | Anxiety symptoms with or without a life-threatening somatic illness | 42 (20 LTD patients) | LSD | 2X 200 µg (oral) | Y | STAI-Global, HAM-D, BDI | 5D-ASC, MEQ30 | Decreases in anxiety symptoms (measured by STAI-G) correlated with higher mystical-type experience scores (measured by MEQ) and higher oceanic boundlessness (measured by 5D-AC) |
| Lewis et al., 2023 | Open-label clinical trial | Cancer patients with a depressive disorder | 12 | Psilocybin | 25 mg (oral) | Y | HAM-D | MEQ30 | Decreases in depressive symptoms (measured by HAM-D) were correlated with higher mystical-type experience scores (measured by MEQ-Total, MEQ-Mystical, and MEQ-Ineffability) |
| Other clinical populations | |||||||||
| Sumner et al., 2021 | Randomized controlled trial | Moderate to severe major depressive disorder | 32 | Ketamine | 0.44 mg/kg (intravenous) | N | MADRS | 11D-ASC | Decreases in depressive symptoms (measured by MADRS) were correlated with higher mystical-type experience scores (measured by the unity, spirituality, and insight factors of the 11D-ASC) |
| Gukasyan et al., 2022 | Randomized, waiting-list controlled trial | Unipolar depression | 27 | Psilocybin | 20 mg/70 kg and 30 mg/70 kg (oral) | Y | HAM-D, BDI | MEQ30 | No relationship between depressive symptoms (measured by HAM-D & BDI) and mystical-type experiences (measured by MEQ30) |
| Levin et al., 2024 | Randomized, waiting-list controlled trial | Moderate to severe major depressive disorder | 24 | Psilocybin | 20 mg/70 kg and 30 mg/70 kg (oral) | Y | GRID-HAMD | MEQ30 | Reductions in depressive symptoms (measured by HAM-D) correlated with higher mystical-type experience scores (measured by MEQ30) |
| Murphy et al., 2022 | Randomized controlled trial | Moderate to severe major depressive disorder | 59 | Psilocybin | 25 mg 2x (oral) | Y | QIDS | MEQ30 | Reductions in depressive symptoms (measured by QIDS) correlated with higher mystical-type experience scores (measured by MEQ30) |
| Palhano-Fontes et al., 2019 | Randomized controlled trial | Treatment-resistant major depressive disorder | 29 | Ayahuasca | (mean ± s.d.) 0.36 ± 0.01 mg/ml of-DMT, 1.86 ± 0.11 mg/ml of harmine, 0.24 ± 0.03 mg/ml of harmaline, and 1.20 ± 0.05 mg/ml of tetrahydroharmine (oral)N,N | N | HAM-D, MADRS | MEQ30 | Worsening depressive symptoms (measured by MADRS) correlated to higher scores on the subscale of transcendence of time and space (measured by MEQ30). Other mystical experience factors were not corelated with mood. |
| Roseman et al., 2018 | Open-label clinical trial | Treatment-resistant, moderate to severe major depression | 20 | Psilocybin | 10 mg or 25 mg (oral) | Y | STAI, QIDS, BDI, HAM-D | 5D-ASC | Reduction in depressive symptoms (measured by QIDS) correlated with higher mystical-type experience scores (measured by OBN subscale of 5D-ASC) |
| Sloshower et al., 2023 | Exploratory placebo-controlled, within-subject, fixed-order study | Major depressive disorder | 19 | Psilocybin | 0.3 mg/kg (oral) | Y | HAM-A, GRID-HAM-D, QIDS | MEQ30 | Reductions in depressive symptoms (measured by HAM-D) were correlated with higher mystical-type experience scores (measured by MEQ30) in the placebo session, but not in the psilocybin session |
| Weiss et al., 2024 | Randomized controlled trial | Major depressive disorder | 59 | Psilocybin | N/A | BDI-IA, HAM-D, MADRS, QIDS | MEQ, EDI | Reductions in depressive symptoms (measured by HAM-D) correlated with higher mystical-type experience scores (MEQ) and greater EDI | |
Results
There were 13 clinical trial studies published between 2016 and 2024 included in this scoping review. Table 1 provides a summary of all the included studies.
Study characteristics
Study design
Sixty-nine percent (n = 9/13) of these studies were randomized controlled trials (RCTs); two (22%; n = 2/9) of these RCTs were randomized waitlist trials. Of note, one of the RCTs27 was a long-term follow-up to another trial that was included in this review.7
Population details
Study populations
The results identified two study populations:
In LTD populations, five of the total studies included (38%; n = 5/13) examined anxiety and depression symptoms in participants with either a cancer diagnosis or another life-threatening illness.
The remaining eight of the total studies (62%; n = 8/13) included non-LTD populations: of those, 31% (n = 4/13) of studies included participants with MDD28–31; two (15%) studies included participants with treatment-resistant depression32,33; two (15%) studies included participants with symptoms of moderate to severe depression.34,35
Sample size
Overall, across the two trial categories, the number of participants ranged from 12 participants to 59 participants, with a total of N = 410 across all the trials.
Intervention details
Type of psychedelic substance
Across all trial populations the majority of included studies (n = 10/13) administered psilocybin, one study administered ayahuasca,32 one study administered LSD,19 and one study administered ketamine.28
Psychotherapeutic support
Overall, psychotherapeutic support was included in the majority of studies reviewed (85%; n = 11/13).
Dosing setting
Aside from these two exceptions, the studies generally administered the psychedelic dose in home-like aesthetic environments with artwork, plants, soft lighting, and personal items. One study was a non-interventional follow-up to a clinical trial, and thus did not refer to the dosing setting,27 but this was described in the original trial.7
Outcomes
Anxiety and depression outcome measures
Overall, about half (n = 6/13) of all studies measured anxiety symptoms, and all (100%; n = 13/13) studies measured depressive symptoms. The BDI was the most frequently used measure across all studies (54%; n = 7/13).
Mystical-type experience outcomes measures
Across all trial populations, the most frequently used mystical-type experience measure was the MEQ-30 (85%; n = 11/13), followed by the 5D-ASC (23%; n = 3/13). Other mystical-type experience measures included the 11D-ASC, the Mystical Scale (9-points), the Hallucinogen Rating Scale (HRS), and the EDI. Although the included studies used different validated instruments to assess mystical-type experiences, these tools are generally considered to capture facets of the same higher-order construct. For this reason, we synthesized them under the broader category of “mystical-type experiences,” while specifying in Table 1 which measure was used in each study.
Relationship between clinical symptoms and mystical-type experiences
Overall, the majority (69%; n = 9/13) of studies in both populations identified a positive relationship between the magnitude of mystical-type experiences and improvement in anxiety and/or depression outcomes.
Subscales of mystical-type experiences
Assessment time point
Psychedelic-induced mystical-type experiences were assessed at the end of the dosing day in all of the studies. However, clinical mood symptoms were assessed at different time points across the studies reviewed, as can be seen in Table 2.
Overall, the most frequently used assessment point was 6 weeks after the dosing session, which was employed in 3 out of the 13 studies.7,29,34
| Study | Time point (relative to dosing) | Relationship (Y/N) |
|---|---|---|
| End-of-life populations | ||
| Agin-Liebes et al., 2020 | 4.5 Years (second long-term follow-up) | N |
| Griffiths et al., 2016 | 5 Weeks | Y |
| Holze et al., 2023 | 16 Weeks | Y |
| Lewis et al., 2023 | 2 Weeks | Y |
| Ross et al., 2016 | 6 Weeks | Y |
| Other clinical populations | ||
| Sumner et al., 2021 | 24 h | Y |
| Gukasyan et al., 2022 | 4 Weeks | N |
| 3 Months | N | |
| 6 Months | N | |
| 12 Months | N | |
| Levin et al., 2024 | 4 Weeks | Y |
| 3 Months | N | |
| 6 Months | N | |
| 12 Months | N | |
| Murphy et al., 2022 | 6 Weeks | Y |
| Palhano-Fontes et al., 2019 | 7 Days | Y |
| Roseman et al, 2018 | 1 Day | Y |
| 1 Week | Y | |
| 5 Weeks | Y | |
| 3 Months | Y | |
| 6 Months | Y | |
| Sloshower et al., 2023 | 1 Day | N—after psilocybin. Y—after placebo |
| 1 Week | N | |
| 2 Weeks | N—after psilocybin. Y—after placebo | |
| Weiss et al., 2024 | 6 Weeks | Y |
Discussion
This scoping review explored the relationship between mystical-type experiences and treatment outcomes, examining life-threatening disease populations with anxiety and/or depression, compared to depressive clinical populations with anxiety and depression symptoms. We focused on mystical-type experiences because prior research identifies them as a potential mediator of therapeutic outcomes, and because they capture features of the psychedelic state that are distinct from general intensity. Across the 13 clinical trials reviewed (LTD populations, n = 5; populations with depression, n = 8), we found no substantial difference in the frequency of relationships between mystical-type experiences and treatment outcomes for anxiety and/or depression between these populations. In both groups, mystical-type experiences were generally associated with improvements in anxiety and depression symptoms, with most studies reporting a significant positive relationship between mystical-type experiences and clinical outcomes. In the few studies that did not find such a relationship,27,35 participants still demonstrated sustained reductions in depression and/or anxiety symptoms, but these improvements were not statistically associated with mystical-type experience scores. In both LTD and depressive populations, psilocybin was the most commonly administered psychedelic. There were minor differences observed between the two populations in terms of therapeutic support—while all of the studies in LTD populations provided psychotherapy, two of the studies in depressive populations did not.28,32 The influence of psychotherapeutic support on the relationship between mystical-type experiences and outcomes was, however, not evident. One of the studies that lacked therapy still found a significant positive relationship,28 and the other found a negative relationship.32
Our findings are consistent with previous systematic reviews and meta-analyses that often report positive associations between measures of mystical-type experiences and clinical outcomes.21,37 However, our review also highlights that this relationship is not universal, as some studies in the present review found no significant association between mystical-type experiences and symptom improvement. This is consistent with findings from Kangaslampi’s systematic review,20 which suggests that other aspects of the psychedelic experience, such as emotional breakthroughs and psychological insights, may be equally or more strongly associated with treatment outcomes. Although other aspects of the psychedelic experience may be more influential in predicting treatment outcomes, factors such as the timing of clinical symptom assessment and the therapeutic context of the experience may also contribute to the findings.
The timing of when the relationship between mystical-type experiences and mood outcomes is measured might be relevant to whether a significant relationship is found. Across the studies included in this review, a variety of time points were employed to assess clinical symptoms, from 1 day after dosing to 4.5 years later. Two studies27,31 initially found a significant relationship between mystical-type experiences and treatment outcomes, which was no longer significant when assessed at the long-term follow-up points. In one study, the significant relationship found at 4-weeks after dosing was absent 3-, 6-, and 12-months later.31 In the other study, there was a significant relationship 6-weeks post dosing,7 which was no longer significant at the 4.5 year follow-up.27 This suggests that, while mystical-type experiences might be predictive of initial treatment response, they could be less important in determining whether these responses persist over time. It is also possible that the association between mystical-type experiences and treatment outcomes was no longer significant at a later time point because of the benefits of psychedelic-assisted therapy diminishing over time. However, one study found that the correlation between mystical-type experiences and mood symptoms persisted up until the last follow-up point, 6-months post dosing.33 These mixed results make it difficult to draw conclusions about whether a significant relationship mediates long-term reductions in depression or anxiety symptoms. While many studies conduct long-term follow-ups, the correlation between the acute psychedelic experience and persisting treatment effects is not often explored. Future studies should aim to include these analyses to determine the significance of different aspects of the acute experience in mediating long-lasting improvements in clinical symptomatology.
The majority of studies in this review were conducted in similar dosing environments, typically utilizing comfortable rooms with curated aesthetics, pre-selected playlists, and the use of eyeshades and headphones. Although this consistency in setting is helpful in standardizing conditions across trials, it limits our ability to determine how context may influence the occurrence of mystical-type experiences and their relationship to clinical outcomes. One study28 stood out for administering psychedelics in a notably different environment—specifically, an MRI scanner. Although the study still reported a relationship between mystical-type experiences and clinical outcomes, it involved ketamine, a dissociative rather than a classical psychedelic, which may affect the extent to which environmental context shapes the experience. Notably, the two studies that did not find a relationship between psilocybin-induced mystical-type experiences and clinical outcomes used the same therapeutic context as those that did,30,35 making it difficult to definitively determine the role of context. Of these two studies, one30 found a correlation between mystical-type experiences and reduction in depression following placebo, but not psilocybin, suggesting that certain therapeutic contexts may increase the likelihood of reporting mystical-type experiences, regardless of pharmacological effects. Considering this, future studies should systematically explore how the environment or “setting” in psychedelic-assisted therapy trials may influence the quality of the psychedelic experience, as well as clinical outcomes. In addition to the physical environment, the beliefs, language, or therapeutic approach of therapists and monitors can significantly influence participants’ “mindset” and may be equally as important in shaping the psychedelic experience and mediating clinical outcomes. Therefore, gaining a better understanding of how various factors of the therapeutic context may influence clinical outcomes is essential for understanding the mechanisms through which psychedelic-assisted therapies produce their therapeutic effects.
Limitations
This review poses a few limitations. First, although the aim was to compare two populations, namely participants with a life-threatening disease and participants with anxiety and depression symptoms not associated with an LTD, there was an unequal number of studies representing the two populations. Thus, differences between LTD populations and other populations might have been missed due to the smaller sample size of included LTD studies. Second, statistical comparisons between the two populations were not conducted because of the nature of the scoping review process. Future studies could employ a meta-analysis approach to reveal any significant statistical differences between different study populations.
Conclusion
This review compared patients with a life-threatening disease diagnosis to depressive clinical populations and assessed the relationship between mystical-type experiences induced by psychedelics and depression and anxiety outcomes. No obvious differences in the frequency of observed relationships between mystical-type experiences and treatment outcomes emerged between these two populations, with most studies finding a positive relationship. Although it is possible that mystical-type experiences present different features in patients facing a terminal diagnosis, the available data do not capture these specific details. While mystical-type experiences appear to be commonly associated with improvements in anxiety and depression in various clinical populations, this relationship is likely influenced by multiple factors including the type of psychedelic, the timing of outcome assessment, and the therapeutic context.
Psychedelic Science