This scoping review (s=53) examined reports of repressed memory recovery in psychedelic contexts and found that most of the literature focused on LSD, with little agreement on what repressed memory means. It found only limited evidence for proposed psychological or brain-based explanations, and no consistent proof that psychedelics reliably recover repressed memories.
Rationale
Reports of resurfaced repressed memories during psychedelic experiences have circulated for decades and still emerge today. However, the veracity of repressed memories remains debated, and the mechanisms through which psychedelics might recover alleged repressed memories are unclear.
Objectives
This scoping review aimed to provide an overview of the literature on repressed memory in the context of psychedelics. It examined how repressed memory was defined, which substances were predominantly discussed, which mechanisms were proposed to explain their effects, and whether these mechanisms were empirically supported.
Methods
A scoping review was conducted in line with PRISMA-ScR guidelines. Web of Science, PubMed, PsycINFO and Google Scholar were searched for relevant publications. Fifty-three sources met eligibility criteria. Data were charted on study design, psychedelic substance, definitions of repressed memory, results, and proposed mechanisms.
Results
Most publications focused on lysergic acid diethylamide (LSD) in relation to repressed memory. Few sources provided a definition of repressed memory. Proposed mechanisms on how psychedelics might influence repressed memory included psychoanalytical reductions of defensive memory blockades and neurobiological alterations of executive control. However, empirical support for these mechanisms was limited.
Conclusions
The included literature did not offer a coherent explanation on how psychedelics could recover repressed memories, nor consistent evidence that they did so reliably. Future work should provide clear definitions of repressed memory in the context of psychedelics, test proposed effects of psychedelics on memory and executive control across multiple psychedelic substances, include placebo-controlled designs, and account for the potential occurrence of false memories.
Papers cited by this study that are also in Blossom
Anderson, E. W., Rawnsley, K. · European Neurology (1954)
Horák, M., Hasíková, L., Verter, N. et al. · Journal of Psychoactive Drugs (2018)
Johnson, M. W., Richards, W. A., Griffiths, R. R. · Journal of Psychopharmacology (2008)
Johnson, M. W., Maclean, K. A., Reissig, C. J. et al. · Drug and Alcohol Dependence (2011)
In recent years, classic psychedelics and related entactogens such as MDMA have been promoted as potential treatments for psychiatric disorders, and some public accounts and case reports have suggested that they may also help people recover repressed or dissociated memories, including memories of trauma. The authors note that these claims are emotionally compelling but sit within an unresolved debate in clinical and cognitive science about whether repressed memories exist, how they might be recovered, and how accurate such recollections are when they emerge during psychedelic experiences. Griesfeller and colleagues therefore set out to conduct a scoping review of the psychedelic literature to examine how repressed and dissociated memories are discussed, whether any empirical consensus exists on how psychedelics might influence memory, and what evidence supports claims that psychedelics can uncover repressed memories. They state that no previous overview had systematically evaluated the mechanisms proposed to explain memory recovery in psychedelic contexts.
The researchers conducted a scoping review in line with PRISMA-ScR guidance. They searched four databases: ProQuest, Web of Science, PubMed and PsycINFO, and also added Google Scholar to capture grey literature. The preregistered search plan was available on the Open Science Framework, although the extracted text notes two deviations from that plan: ProQuest was excluded because it returned an unmanageable number of hits, and Google Scholar was added. Studies were included if they made any connection between psychedelics and repressed memory, or closely related concepts. The review process was conducted in two stages. Stage 1 involved full-text screening of 388 publications from Web of Science, PsycINFO and PubMed, with 13 included and 18 more identified through reference checking. Stage 2 involved title and abstract screening of 443 Google Scholar records, with 8 included and 14 additional sources found via reference checking. The authors also report that 26 papers were inaccessible through institutional access and 23 of those remained excluded. Two raters screened the sources and extracted data into an Excel file. The extracted variables included study type, psychedelic substance, definition of repressed memory, and the nature of the connection made between psychedelics and repressed memory. The included sources were also assessed for quality using guidelines derived from a prior meta-methods paper. Quality assessment was completed separately for the two stages. Not all criteria were applicable to every source, particularly because some were theoretical or methodologically under-described. Overall, 52.8% (n = 28) of the included studies were rated medium quality, 20.8% (n = 11) low quality, and 26.4% (n = 14) high quality.
Across the review process, 53 sources were included. Agreement between raters in stage 1 was high for full-text screening and reference checking, but stage 2 abstract screening showed low agreement because one rater identified eligible sources missed by the other; these were then reviewed and included after discussion. The paper also notes that most sources did not clearly define repressed memory, so inclusion often depended on contextual links rather than explicit definitions. In terms of study type, 19 sources were theoretical reviews, 14 were experimental studies, 18 were observational patient accounts, one was a personal account, and one was an extensive literature review. Among the theoretical reviews, five used explicit frameworks such as Freudian psychoanalytic theory. The experiments were mostly older and often lacked features now considered standard, such as placebo or control groups; five did include a placebo condition. Across the experimental literature, there was no consensus on whether LSD facilitates the emergence of repressed memories. Some sources treated resurfacing of repressed memories as a core or even exclusive LSD effect, while others described it as generally accepted. For ayahuasca, five sources linked it to repressed memory, including three that specifically framed it as aiding the healing of traumatic memories, one that connected it to addiction treatment through processing recovered memories, and another that suggested it helps recover memories and emotions needing attention. The review found that no source provided a specific definition of repressed memory, and only five defined related constructs such as dissociative amnesia, recovered memories or repressed priors. Across the included literature, 14 experiments suggested that psychedelic-assisted psychotherapy reduced psychological defences, intensified emotions and facilitated recovery of repressed material, with judgements of improvement relying mainly on self-report and therapist assessment. Other experiments examined cognitive and psychological functioning under the influence of psychedelics; findings were mixed, including some reports of earlier or previously inaccessible memories alongside memory distortions and unstable recall. A study of ibogaine-assisted therapy for substance use was described as associated with previously unconscious material and improved addictive behaviour, but the authors emphasise that the lack of a controlled design limits generalisability. Most sources focused on LSD: 69.8% (n = 37) of included sources addressed LSD and repressed memory, with 35.8% (n = 19) discussing LSD alone and 34% (n = 18) discussing LSD alongside other psychedelics. The review highlights that claims about ayahuasca or MDMA recovering repressed memories were much less common in the included literature. In fact, only two qualitative studies mentioned ayahuasca in this context, and none mentioned MDMA. When the authors examined proposed mechanisms, 54.7% (n = 29) of sources offered no explanation for how psychedelics might trigger memory recovery. Of the remainder, 33.9% (n = 18) discussed psychoanalytical, neurobiological, or mixed mechanisms. Psychoanalytical accounts suggested psychedelics reduce defensive repression and allow buried memories to emerge. Neurobiological accounts proposed that psychedelics alter dopaminergic signalling in frontostriatal circuits, reduce top-down executive control, increase resting-state amygdala activity, or induce neuroplastic changes in perceptual and limbic networks. However, the review states that none of the papers provided experimental data supporting these mechanisms, and only 7.5% (n = 4) explicitly acknowledged the lack of empirical evidence. The review also found that all 53 sources discussed the emergence or recovery of unconscious memories after psychedelic use, but the authors judged that many discussions may actually refer to normal forgetting or to initial disclosure of traumatic experiences rather than true recovery of inaccessible memories. Very few sources considered whether the reported memories might be false or partially false. Specifically, 86.8% (n = 46) did not discuss possible inaccuracy. Among the seven that did, some argued that factual accuracy was not the main issue because the content still reflected material needing therapeutic attention. Only one source explicitly warned that recovered memories should not be taken as literal or factual.
Griesfeller and colleagues conclude that the reviewed literature provides no coherent empirical basis for claims that psychedelics recover repressed memories. They emphasise that most sources implicitly or explicitly portrayed psychedelic-induced memory recovery as therapeutically beneficial, but the underlying concept of repressed memory was usually undefined, making comparisons across studies difficult and increasing the risk of overinterpretation. They also note that some papers may have been referring to ordinary memory phenomena or to non-disclosure of trauma rather than to genuinely inaccessible memories. The authors position their findings as a challenge to broader claims that psychedelic experiences reveal hidden traumatic material. They argue that the literature’s heavy focus on LSD does not justify extrapolating those claims to other psychedelics such as ayahuasca or MDMA, especially given pharmacological differences and the lack of consensus even within LSD studies. They further stress that discussions of memory recovery under psychedelics often lacked mechanistic support and that assertions about reduced executive control, suppressed defences or other proposed pathways remain speculative. The discussion highlights several uncertainties and limitations. The review itself cannot test whether psychedelics do or do not recover repressed memories; it can only summarise how the literature addresses the topic. The search was limited to English-language sources, and dissociative substances such as ketamine and salvinorin A were excluded. The authors also caution that recovered memories may in some cases be false memories, and that heightened suggestibility under psychedelics could matter for how traumatic experiences are interpreted. However, they note that direct evidence on false memories in psychedelic contexts remains scarce and has found no or only limited support for increased false memories after ayahuasca or MDMA. Despite the lack of empirical consensus, the authors state that these experiences may be deeply meaningful for the people who report them. They argue that clinicians working in psychedelic-assisted therapy should respond with empathy and care, avoid dismissing subjective experiences, and also brief patients about the possibility that recovered memories may not be fully accurate in order to reduce the risk of false memory formation or re-traumatisation. They call for more rigorous research on how psychedelics affect memory encoding, storage and retrieval, including placebo-controlled studies of episodic and autobiographical recall, emotional memory, suggestibility and false-memory susceptibility.
The authors conclude that the literature linking psychedelics to repressed memories contains no clear definitions of what counts as a repressed memory and no coherent mechanism explaining how such memories might be recovered. They state that there is currently no empirical basis for claims that psychedelics recover repressed memories. At the same time, they emphasise that people who report such experiences should be treated with empathy and care, while future research should address memory processes under psychedelics more rigorously.
To adequately evaluate the surfacing of seemingly repressed memories during psychedelic-assisted therapy, it is essential to establish what scholars have noted on how psychedelics might affect repressed memories. However, to this date no overview has been published that evaluates the mechanisms proposed to explain memory recovery during a psychedelic experience. Therefore, we carried out a scoping review to provide a systematic examination of how the concept of repressed and dissociated memories is addressed within the psychedelic literature. The aim was to clarify whether empirical consensus exists on how psychedelics influence memory, and to evaluate the evidentiary basis of claims that psychedelics can uncover repressed memories.
The intense debate regarding the existence, veracity and plausibility of repressed memories is referred to as the memory wars, which still remain active today. The term gained prominence with the publication of "The Memory Wars: Freud's Legacy in Dispute" (Crews 1995). Within the debate, the term repressed memory has been defined as "the idea that people can unconsciously block traumatic autobiographical experiences and eventually regain access in accurate form" (Dodier et al. 2024, p. 574). While suppression, the conscious blocking of memories, is more widely accepted, the idea that memories are unconsciously blocked remains controversial. Repressed memories of trauma are often claimed to have been recovered in theraphy, which goes against the general findings that traumatic events are typically very strongly remembered and not easily forgotten (e.g.,). This can happen when, for example, therapists suggest to their clients that their mental health problems are the result of buried repressed memories of trauma and that in order to heal, they need to exhume these repressed memories of trauma culminating eventually in the creation of false memories (e.g.,. Importantly, because these false memories are often indistinguishable from real memories, they can have serious consequences for both the individual and others, including psychological harm, distortions in self-concept, and legal repercussions such as false accusations of abuse and even wrongful convictions
The scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Four databases (i.e., ProQuest, Web of Science, PubMed, and PsycINFO) were selected. The preregistered search plan can be accessed on the Open Science Framework: h t t p s : / / d o i . o r g / 1 0 . 1 7 6 0 5 / O S F . I O / T D C X K. During the search process, two deviations from the p r e r e g i s t e r e d strategy were made. First, the ProQuest database was excluded from the search, as it resulted in 31,554 hits, which was unmanageable within the available timeframe. Second, Google Scholar was added to access grey literature. Sources were selected based on the eligibility criteria seen in Table. Several search terms were selected to guide the scoping review. The full search query can be found in Supplementary Information (SI) 1. The search queries adjusted to each database are displayed in SI 2. The search query that was adjusted for the term ''MDA'' can be found in SI 3. After conducting the search, five sub research questions were added to assist the structure of the scoping review:Which psychedelic substances were studied? (2) How were repressed memories defined? (3) Which study types and methodologies were employed? (4) Which effects were discussed between psychedelics and repressed memories? and (5) Which exploratory mechanisms were proposed? These sub-questions were not preregistered as they emerged after the scoping search and were formulated to better structure the results. The review was done in two stages. During stage 1,388 publications were screened with a full-text approach on Web of Science, PsycINFO and PubMed, of which 13 were included. An additional 18 sources were subsequently found through reference checking. Stage one was finalised on the 13th of November 2024. During stage 2,443 publications were screened based on title and abstract on Google Scholar, of which 8 were included. After reference checking, an additional 14 were found. This search was finalised on the 11th of June 2025. A total of 26 papers were inaccessible through institutional access. The older articles were published before the widespread digital dissemination of research, making them difficult to trace. Several efforts were made to gain access to the remaining papers. Two of these papers were provided by researchers with different institutional access. A total of 12 authors were contacted through ResearchGate, of which one responded and provided access. The authors of the remaining 12 inaccessible sources were deceased or did not have any contact information provided and therefore could not be contacted. The total of 23 papers that remained inaccessible were excluded from this review. Additionally, personal networks were used to access two more papers. Papers were screened for all search terms and included if any type of connection was made between psychedelics and repressed memory, or similar concepts. All papers found through the scoping review were screened by two raters, who discussed screening criteria and the PRISMA-ScR strategy together beforehand. Stage 1 was screened by two raters simultaneously, while stage 2 was screened at two separate times within one month of each other. The chosen data extraction points can be seen in SI 4. The extracted information was saved in an Excel file and later compared between the two raters. A summary of this file is shown in SI 7. The quality of the included 53 sources was assessed using the guidelines provided by. They designed this quality assessment based on a meta-analysis of assessment tools conducted by, who evaluated items used on 121 published critical appraisal tools. Quality assessments allow for better interpretation and contextualisation of different research papers, as it gives an indication of the validity of each study. The quality assessment was done by two different researchers, each assessing one of the two stages of this scoping review. The questions used for this quality assessment can be found in SI 5. An overview of the assessment can be found in SI 6. Not every quality criterion was applicable for each study, as not all of them were empirical or elaborately discussed their methodology. Overall, 52.8% (n = 28) of the included studies were of medium quality, 20.8% (n = 11) were of low quality, and 26.4% (n = 14) were of high quality.
Details of the searches on Web of Science, PubMed and PsycINFO during stage 1 can be found in Fig.. The agreement rate of the researchers in stage 1 was 95.2% (Cohen's κ = 0.95, n = 388) for the full-text search, and 97.0% (κ = 0.97, n = 1190) for reference checking. The details of the search on Google Scholar during stage 2 can be found in Fig.. Agreement rates of abstract screenings during stage 2 were low, with 14.5% (κ = 0.14, n = 396), as one researcher identified eligible sources not found by the second researcher. However, these sources were subsequently checked and approved for inclusion by the same researchers. The agreement for reference checking in stage 2 was 72.5% (κ = 0.72, n = 2269). ). Notably, most papers lacked clear definitions of repressed memory, thus paper inclusion often relied on contextual links to psychedelics rather than explicit definitions (e.g.: ''… psychedelics function as "nonspecific amplifier drugs that project into consciousness (amplify) unconscious memories, fears and other subjectively variable (nonspecific) psychological material ''). The undefined terms that were interpreted to refer to a concept similar to repressed memories can be found in SI 8
Out of the 53 included studies, 19 were theoretical reviews, 14 were experimental studies in which different behavioral outcomes were assessed after guided administration of psychedelics, 18 were observational patient accounts, one was a personal account, and one was an elaborate literature review. Of the theoretical reviews, five studies used specified frameworks to guide the approach of their research such as Freudian psychoanalytic theory (Koslowski et al.
Data points (i.e., study type, type of psychedelic, definition of repressed memory, and connection between psychedelic and repressed memory) were extracted from the included 53 sources. A comprehensive overview of this extraction can be found in SI 7. The publication dates of included articles across decades can be seen in Fig..
Out of the 14 experiments included in this review, the quality assessment of four of them was low, while ten of them scored in the medium range (See SI 6). Most of the experiments are rather old, leading to methodological limitations that nowadays are seen as standard practice such use of a placebo or control group. Five of the experiments worked with a placebo alongside the administered psychedelicpsychedelics. Across these sources, there was a lack of consensus on how and whether LSD facilitates the emergence of repressed memory. Some authors argued that the resurfacing of repressed memories is a core experience of LSD, and might even be exclusive to LSD. Furthermore, some sources claimed that the effect of LSD on repressed memory is generally accepted (Cutner 1959) and happens "practically without exception"The second most discussed substance was ayahuasca, with 9.4% (n = 5) of included sources mentioning a connection between ayahuasca and repressed memory. Three papers linked ayahuasca specifically to the healing of traumatic memories that were previously repressed (Frecska et al. 2016; Inserra 2018; Weiss et al. 2023), one described its usefulness in treating drug addiction through the processing of the recovered repressed memories (Bouso and Riba 2014), and another postulated that ayahuasca can recover those memories and emotions most in need of processing). 1
Included sources (N = 53) were further examined for definitions of repressed or related memory constructs to assess whether authors used consistent concepts or differed in their understanding of repressed memory. However, no source included a specific definition of repressed memory, and only five sources included definitions of related constructs. These include dissociative amnesia, recovered memories, and repressed priors, which were interpreted to reflect the concept of repressed memory (see SI 8). Dissociative amnesia was defined as: "Dissociative amnesia, a condition characterised by impaired retrograde memory functioning and loss (or repression) of autobiographic traumatic memory, which is not related to structural 1 One additional source discussing ayahuasca in relation to repressed memories was identified after completing the literature search and data extraction (Horák et al.2018). It was not included in the quantitative counts because it was not part of the screened dataset, but is noted here for completeness.. Across studies, the psychedelic assisted psychotherapy reduced psychological defences, intensified emotions and facilitated the recovery of repressed material. These properties were often seen as therapeutically beneficial. Judgements of patient improvement relied mainly on self-reports and assessment by the therapists. The experiments focusing on cognitive and psychological functioning under psychedelic influence implemented different approaches. Some used intelligence testingOut of the remaining two experiments, the study conducted byaimed to gain understanding of the recall process of the earliest accessible memory under psychedelic influence. The findings were mixed, as some participants recalled earlier memories or previously inaccessible material and some mainly experienced memory distortions and instable recall). The study done byfocused on ibogaine-assisted therapy for the treatment of substance abuse. The findings of this experiment showed that treatment was associated with the emergence of previously unconscious material and the improvement in addictive behaviours. However, conclusions remain ungeneralizable due to the absence of a controlled methodology. Across all 14 experiments, psychedelics facilitated a reduction in inhibitory control and increased the emotional experience of participants. However, the methodological limitations and lack of controlled experimental set-up do not allow for a firm conclusion regarding the effects of psychedelics on the variables in question.
To assess whether repressed memory is predominantly associated with a specific psychedelic substance or discussed across different psychedelics, each source was examined for the psychedelic it studied or described. Results showed that 69.8% (n = 37) of included sources focused on the connection between LSD and repressed memory. Out of these sources, 35.8% (n = 19) exclusively discussed LSD, whereas 34% (n = 18) papers discussed LSD along with other Interestingly, some sources (n = 3) described that the recovered memories may re-traumatize the subject, which could lead to maladaptive behaviour or cause problems in processing and integrating the traumatic memory (Elfrink and Bergin 2025; Evans et al. 2023; Inserra 2018). Furthermore, some sources (n = 2) noted that recovered memories might not immediately make sense to the patient and thus required further analysis before the patient realises that it was a recovered memory.
Explanations on how psychedelics lead to the recovery of repressed memories were extracted from all sources (N = 53). Notably, 54.7% (n = 29) of sources did not include an explanation of any potential mechanism or reason for why psychedelics would be able to trigger memory recovery of repressed memories. 33.9% (n = 18) of sources discussed psychoanalytical mechanisms, neurobiological mechanisms, or both. Psychoanalytical mechanisms were mentioned by 28.3% (n = 15) of papers. These mechanisms were assumed to reduce defensive or protective repression of memory, thereby allowing the recovery of previously repressed memories (Busch and Johnson 1950; Garcia-Romeu and Richards 2018; Healy 2021; Hoch 1957). Neurobiological mechanisms were proposed by 13.2% (n = 7) of papers. Several of these papers mentioned that psychedelics dysregulate dopaminergic signalling within frontostriatal networks, which decreases top-down executive control and thereby enhances spontaneous memory recall). Additionally, some authors stated that increased resting-state amygdala activity caused by psychedelics facilitates spontaneous and emotionally charged memory retrieval (Frecska et al. 2016; Inserra 2018). Lastly, psychedelics were proposed to induce neuroplastic changes in perceptual and limbic networks, which reduces the suppression of unwanted memories. However, none of the papers included experimental data that supported their assertions. The lack of research and empirical evidence for psychoanalytical and neurobiological mechanisms was acknowledged by only 7.5% (n = 4) of papers. More specifically, authors mentioned that the recovery of repressed memories due to psychedelics has not been documented in controlled and generalizable studies yet and call for further studies that test these mechanisms"Dissociative amnesia is the failure to remember autobiographical information in the absence of brain damage, it is a protective mechanism protecting us from pain caused by the memory. Research shows that the memory is unavailable for retrieval for a period of time, however it is not lost nor forgotten'' (Rubin-Kahana et al. 2021, p. 250). Repressed Priors were defined as: "Repressed Priors (RPs), which are defined by the inability to become reconsolidated or removed, despite ongoing error signal production.''. Lastly, recovered memories were defined as: "Memories of actual events, typically traumatic events, that are forgotten for a period of time and later remembered.''.
Although none of the sources defined repressed memory, all papers (N = 53) discussed the emergence or recovery of unconscious memories after psychedelic trips. Therefore, the contexts in which authors associated psychedelics with repressed memories were examined. Additionally, it was assessed whether authors discussed potential benefits or risks to recovering repressed memories with psychedelics. been used to denote normal forgetting or a failure to disclose traumatic memories. This is especially relevant given that non-disclosure of traumatic experiences, especially childhood sexual abuse, is well-documented and often driven by social, cultural, and familial pressures such as shame, fear of judgment, and potential loss of social support). Psychedelic-assisted therapy sessions are typically designed to provide a supportive, nonjudgmental environment, which may facilitate the first-time disclosure of previously suppressed experiences rather than the retrieval of genuinely inaccessible memories (Dodier et al. 2024;. Consequently, what has been interpreted in the literature as recovery of repressed memory may in some cases reflect disclosure of consciously held but never reported experiences). Furthermore, given that it is unclear how psychedelics affect the accuracy of autobiographical memory retrieval, the accuracy of reported repressed or recovered memories during psychedelic sessions is difficult to judge without external confirmation (Kangaslampi and Lietz 2025). Nevertheless, the term repressed memory entails that the memory represents an accurate experience, and by using the term, authors might have unintentionally suggested that the recovered memory is fully accurate.
Next to the inconsistent use and definition of repressed memory, the finding that most reviewed papers focused on LSD and its effects on memory for trauma raises concerns when compared to public claims that assume that this effect generalizes to other kinds of psychedelics. For instance, although personal reports like those of Tim Ferris or Amy Griffin have linked ayahuasca or MDMA to the recovery of repressed memories, only two qualitative studies mentioned such an effect for ayahuasca (Ferris 2024; Griffin 2025; Horák et al. 2018; Renelli et al. 2020), and none mentioned MDMA in this context according to this review. Nevertheless, the information cited in these reports predominantly includes literature focused on LSD, despite pharmacological differences between types of psychedelics, and the lack of consensus even within LSD studies regarding its capacity to recover repressed memories). This generalization from LSD to other psychedelics without sufficient empirical support is therefore potentially harmful, as other psychedelics may have different effects on memory and consequently lead to unanticipated outcomes. However, the unclarity about the exact effects of psychedelics on memory, and the danger of overgeneralization or misinterpretation of findings is true even for LSD, as included publications did not provide a clear explanation on which mechanisms could underpin the effects of psychedelics on recovered and repressed memories. Much of the available literature did not offer any rationale as to why
Given that the veracity of recovered memory is still debated, each source was assessed for whether it accounted for the possibility that recovered memories might be fully or partially false. Out of all papers (N = 53), 86.8% (n = 46) did not discuss or imply any doubt as to whether the recovered memories were real or false. Among the remaining seven papers that acknowledged that recovered memories might be fabricated, several argued that the reality of the memories was irrelevant, as their content still reflected issues that need to be processed by the patient (Buckman 1967; Chandler and Hartman 1960;. Furthermore, some authors refrained from judging the veracity of recovered memories). Only one identified source explicitly mentioned that recovered memories should not be seen as literal or factual, and referred to academic work on false memories.
This scoping review provided an overview of the existing literature on repressed memories in the context of psychedelics. Using PRISMA-SCR criteria, 53 eligible sources were identified. These sources were reviewed to clarify how the construct of repressed memory has been defined across the literature, which psychedelics have predominantly been discussed in this context, whether there is consensus on how psychedelics influence repressed memories, and whether claims are empirically supported. Most identified sources argued that psychedelics can recover repressed memories either implicitly or sometimes explicitly, and that this recovery is beneficial in therapeutic settings. However, definitions of repressed memories were often missing. The literature mainly discussed LSD and its effects on repressed and recovered memories. About half of the included sources did not offer any explanation on how psychedelics might affect repressed memory. The remaining sources proposed psychoanalytic or neurobiological mechanisms but did not support their claims with empirical evidence. The relevance of the findings to the broader field of psychedelics and memory will now be explained. The lack of specific definitions for repressed memories makes it difficult to compare outcomes across papers and leaves room for individual interpretation of proposed effects, which risks them to be overstated or misread). Similarly, by not specifying what was meant with the term repressed memory, it is possible that some authors in fact referred to normal memory-related phenomena. For example, the term repressed memory might have al. 2025;). Nevertheless, effects might differ between psychedelics, and the possibility of false memory formation is warranted when interpreting findings until further research on psychedelics and repressed or false memories exists. Lastly, it is important to emphasize that despite the absence of a coherent empirical explanation for how psychedelics might recover memories, and despite uncertainty regarding the veracity of such memories, these experiences carry profound significance for the individuals who report them. Recovery of previously repressed memories is not exclusive to psychedelic contexts but is also reported in general therapeutic settings, and their emergence can be both beneficial and harmful to the individual (Carey et al. 2026). Therefore, regardless of the current state of the empirical evidence, the clinical impact of these experiences should not be dismissed, and practitioners working in psychedelic-assisted therapy should be prepared to support individuals who report such memories in a careful and empathetic manner. Similarly, future research investigating repressed or false memories in psychedelic contexts should be cautious in how findings are communicated and should not inadvertently dismiss or invalidate the subjective experiences of individuals who report recovered memories. However, it is also important to acknowledge the lack of empirical consensus, and to brief patients about the possibility that recovered memories might not be fully accurate to avoid false memory formation or re-traumatization (Kangaslampi and Lietz 2025).
This is the first literature review on the topic of psychedelics and repressed memory. While it provides an overview of existing research, it did not empirically test the link between psychedelics and repressed memory. Therefore, conclusions are purely based on interpretations of the existing literature and cannot directly deny nor confirm an effect of psychedelics on repressed memory. Additionally, as the search was limited to sources written in English, relevant publications in other languages may have been overlooked. Furthermore, the scope of this review was limited to classic psychedelics and related entactogens, meaning that dissociative substances such as ketamine and salvinorin A, which share some phenomenological overlap with psychedelics and have been associated with experiences that may resemble recovered memoriespsychedelics might have such a memory recovery effect and were thus based on unsubstantiated and likely subjective assumptions on psychedelics and traumatic memories. Furthermore, most neurobiological and psychoanalytical explanations assumed that psychedelics reduce executive (or defensive) control and thereby allow for otherwise ''guarded'' memories to be recalled). However, whether and how psychedelics affect autobiographical memories and memory recall in general has not been established yet (Kangaslampi and Lietz 2025). Thus, conclusions that psychedelics lead to the recovery of previously repressed memory are premature and currently not empirically supported. Nevertheless, many sources reported a recovery of previously unconscious memories after psychedelics. Because it is unclear whether such an effect is possible, it is important to consider the possibility that at least some of these memories might instead be false memoriesto increase familiarity, which describes a subjective feeling that stimuli are known even when they have not been previously encountered). Thus, if plausible but previously non-remembered events are discussed under psychedelics, individuals might be at increased risk of forming false memories. However, the extent to which heightened suggestibility under psychedelics translates into altered memory outcomes in clinical settings remains unclear, and studies on psychedelics and false memory formation are still scarce, and have found no or only limited evidence for increased false memories after ayahuasca or MDMA administration
The results of this scoping review showed that the literature linking psychedelics to repressed memories contained no or unclear definitions on what constitutes a repressed memory and which psychedelic mechanism could aid in the recovery of repressed memories. Together, these findings showed that there is no coherent empirical basis for claims about the recovery of repressed memories under the influence of psychedelics. Considering the increased interest in the use of psychedelics in therapeutic contexts, there is an urgent need for research on how these drugs can affect the encoding, storage, and retrieval of memories. Until such research exists, claims that psychedelics can recover repressed memories are unsubstantiated, but individuals who report such experiences should nevertheless be approached with empathy and care.
Psychedelics a class of serotonin 5-HT2A receptor agonist drugs that can alter or distort perception, mood, and cognitive processes, sometimes causing hallucinations, increased introspection, and other alterations of consciousness." Recovered memory a recollection of a past event which a person was unaware of until the moment of retrieval. Repressed memory a memory of a traumatic event that is unconsciously stored in intact form. Memory suppression a concept that suggests that individuals can consciously block. Dissociative amnesia categorised in the DSM-5 as a dissociative disorder, defined as the inability to recall autobiographical memories.
False memories are recollections of events or details that feel subjectively real but are partially or entirely inaccurate.
The online version contains supplementary material available at h t t p s : / / d o i . o r g / 1 0 . 1 0 0 7 / s 0 0 2 1 3 -0 2 6 -0 7 0 7 6 -x. Author contributions A.G. and L.K. wrote the main manuscript. The scoping review was carried out by A.G. and L.K. Data analysis was done by L.K and assisted by H.O. The idea for this scoping review was proposed by L.K-H. and H.O. The manuscript was critically reviewed by H.O., L.K-H., S.K. and J.R., who provided suggestions and com-
Given the inconsistent interpretations and unsupported claims across identified sources, this scoping review showed that methodologically rigorous and generalizable research is needed to make inferences about the effect of psychedelics on allegedly repressed memories. Recent empirical work further shows that the topic remains highly relevant, as uncertainty about how psychedelic experiences affect autobiographical memory and whether resurfaced memories reflect actual events can cause substantial distress. Therefore, research on repressed memories in psychedelic contexts is not only academically relevant, but also important for participant safety and wellbeing. Novel research could include placebo-controlled trials examining the effects of different psychedelics on memory, such as episodic and autobiographical recall, and emotional memory. Furthermore, establishing a neuropharmacological basis of how psychedelics could influence memory processes and executive control could help clarify the claims found in previous literature. To assess potential risks associated with psychedelics, placebocontrolled trials investigating suggestibility and the susceptibility to false memory formation under psychedelics are needed. For example, preparatory information provided to participants prior to sessions could be manipulated to see the effects of suggestibility on psychedelic experiences, and false memory paradigms could be used to see whether there is an increased occurrence of false memories during psychedelic experiences. Furthermore, although research should first establish a foundational understanding of psychedelic effects on non-traumatic memory retrieval and memory accuracy in healthy populations, subsequent research should consider including populations that are most likely to experience the recovery of previously repressed memories. These include individuals with documented trauma histories, individuals who are unable to provide complete biographical accounts, and individuals with personality disorders that are currently systematically excluded from most psychedelic research. However, this poses considerable ethical risks for participants and researchers. Therefore, before such research can take place, clinicians and researchers need protocols for managing recovered memories when they arise, to ensure that experiences are acknowledged without inadvertently reinforcing inaccurate recollections or causing further distress.
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