We conducted an anonymous online survey comprising of 150 items using Nettskjema, a survey solution developed and hosted by the University of Oslo. The participants were asked about a memorable experience after taking MDMA. Psychedelic experiences from classical psychedelics were surveyed in a previous study by the same research group and were therefore not targeted in this study. Participants were recruited via the web pages and social media groups of the Norwegian Association for Psychedelic Science, Rusopplysningen.no – an information service about commonly used drugs – and numerous Facebook-pages for people with an interest in psychedelics. Participation in the study was voluntary and anonymous, and participants did not receive any form of compensation. They were informed that even after they started the survey, they could cancel at any time, and if they did, none of their answers would be stored. In the final question, participants had to confirm whether their data could be used in the study.

Participants completed the survey from March 6^th to August 28^th, 2024. Inclusion criteria were 1) being 18 years or older, 2) fluent in Norwegian (reading, writing, and speaking), and 3) having had a memorable experience with MDMA within the past five years. Responding no to any of these questions led to exclusion from the data set. Participants were asked to report their gender, age, education level, annual income group, and marital status. Due to concerns about data sensitivity and participant identification, we did not ask for other demographic data. They also reported the frequency of MDMA use across their lifetime, and within the past year.

Participants responded to the following questions regarding the most memorable MDMA experience: to what extent they remembered the experience, the setting in which MDMA was taken, whether they had any support during the experience or paid someone to guide them through the experience, motivation to take MDMA (therapeutic or other), collaboration with therapist, guide or trip-sitter if any, dosage, preparation, degree of clear intention, wish for change, co-administration of alcohol or other substances, and integration after the experience. Participants were asked to which degree they agreed that MDMA should be used therapeutically.

Participants were asked about any increased understanding of the significance of past life events during the experience, to what extent they uncovered any associations between current and past interpersonal relationships during the experience, and to what extent they discovered any new or forgotten ways of dealing with difficulties and challenges during the experience.

We also asked the participants about the occurrence of persisting adverse reactions, and the severity and duration of such reactions after the MDMA experience, and if they sought professional help to handle adverse reactions. We also asked about craving symptoms and failed attempts to resist new intake of the substance.

We asked the participants to compare their most memorable experience to other meaningful experiences in life, i.e., how meaningful, how spiritual, how psychologically challenging and insightful the experience was. Furthermore, we asked about subjectively perceived persisting changes in personal well-being/life-satisfaction, purpose and meaning of life, social relationships, mood, behavior, spirituality, as well as attitudes about life, nature, and death.

We also included four standardized questionnaires in the survey: the Psychological Insight Scale (PIS; 29), the Emotional Breakthrough Inventory (EBI; 30a), the Challenging Experience Questionnaire (CEQ; 31a), and the Level of Personality Functioning Scale – Brief Form (LPFS-BF; 32). The first three instruments have been translated and examined for psychometric properties in relation to the study on psychedelics (28), and publications of these examinations are currently underway (33). The Norwegian version of LPFS-BF has been translated and validated by other researchers (34).

PIS is a seven 7-item questionnaire assessing change in insight following a psychedelic experience, and behavioral change (29). It is scored on a scale with the anchors 0 to 100, where 0 represents “no more than usual” and 100 represents “more than usual”. An example item is “I have learned important new ways of thinking about my ‘self’ and my problems”. Increased PIS score represents increased insight.

EBI is a 6-item questionnaire that was developed to map emotional breakthrough following a psychedelic experience (30). The EBI consists of six statements scored on a scale from 0 (“no, not more than usual”) to 100 (“yes, entirely or completely”). An example of an item from the questionnaire is “I faced emotionally difficult feelings that I usually push aside.” Higher EBI score represents a higher level of emotional breakthrough.

CEQ is a 26-item self-report questionnaire measuring perceived challenging aspects of a psychedelic experience (31). Participants were asked to rate their most memorable experience with a classic psychedelic substance on a five-point Likert scale ranging from 0 (“none: not at all”) to 5 (“extreme”). The CEQ is divided into seven dimensions: 1) Isolation, 2) Grief, 3) Physical distress, 4) Fear, 5) Insanity, 6) Paranoia, and 7) Death. An example of an item from the questionnaire is “Isolation and loneliness.” Higher CEQ scores represent higher degrees of perceived challenges.

LPFS-BF is a 12-item self-report questionnaire designed to assess an individual’s overall level of personality functioning (32, 35). The items are rated on a scale from 0 (“not at all”) to 3 (“very much”). A sample item from the LPFS is “I often don’t know who I really am”. Higher LPFS-BF scores represent higher levels of functional impairment. For each of the 12 items, participants also indicated whether the aspect in question had changed following the MDMA experience, on a scale from -5 (“worse”) to 5 (“better”) with 0 as a neutral mid-point.

We asked the participants if they had been diagnosed with or suspected that they would meet the criteria for the following mental disorders (“psykiske lidelser” in Norwegian), and whether the condition was diagnosed by a professional: social anxiety, panic disorder, OCD, depression, bipolar disorder, psychosis/schizophrenia, eating disorder, PTSD, attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and suicidality. Furthermore, we asked about substance use disorders, including nicotine dependence (daily smoking), and abuse of or addiction to alcohol or other substances. The latter included illegal drugs other than MDMA, and addictive prescription drugs. We asked about concurrent use of the following drugs together with the memorable MDMA experience: dissociatives (ketamine, PCP, etc.), cannabis (hashish, marihuana, THC), stimulants (amphetamine, methamphetamine, Ritalin), cocaine, alcohol, psychedelics (LSD, Psilocybin/magic mushroom, 2-CB, Ayahuasca, DMT [N,N-dimethyltryptamine], 5-MeO-DMT [5-methoxy-N,N-dimethyltryptamine], Peyote/mescaline), opiates (morphine, heroin, methadone, OxyContin, codeine, opium), inhalants (glue, ethyl chloride, nitrous oxide, amyl nitrate or butyl nitrate), anxiolytics (benzodiazepines, Valium, Vival, Stesolid, Xanor, Ativan, Rivotril, barbiturates, GHB, Rohypnol), and other.

In the consent form, it was stated that the survey should not be interpreted as an endorsement of MDMA or an encouragement for its use. We did not collect identifiable information such as name, email address or IP address. A preliminary request was submitted to the regional committee for medical and health research ethics (REK, reference number 212268). Because we only collected anonymous data, the committee deemed the study exempt from full evaluation, and we were allowed to proceed with the data collection. The study was subsequently approved by the Internal ethics committee at the Department of Psychology, University of Oslo (reference number 18183844). We used a secure web application for data storage (Services for Sensitive Data; TSD), which meets requirements for the processing and storage of sensitive research data.

Prior to the data collection, the survey was reviewed by a focus group of five volunteers recruited from the Norwegian Association for Psychedelic Science as well as a designated user representative at Østfold Hospital Trust. Their task was to flag problematic, incomprehensible or ambiguous questions. As a result of feedback from the focus group, we changed the wording of some questions, but no questions were added or removed.

We present descriptive statistics for demographics, previous use of MDMA, lifetime history of self-reported mental disorders and substance use disorders, characteristics of the most memorable MDMA experience, and persisting adverse reactions and benefits from the experience. We used chi-square-tests and correlations (Pearson’s r, Cramer’s V) to investigate gender and age differences. Analyses were performed using IBM SPSS v30.0.

Of 654 participants who completed the survey, 608 were deemed eligible for the data analysis, 366 of which reported MDMA without concomitant use of other substances. See Figure 1 for details of participant exclusion and selection of subsamples. Of the 608 included in the total sample, 234 were female (38.5%), 368 male (60.5%) and six reported as non-binary (1%, see Table 1 for demographics). Most participants were 45 years old or younger (89%), 66.3% were under 36, all were under 65 years of age. On income, 16.3% reported below NOK 300,000 in yearly income, which is well below poverty levels, whereas 11.7% reported above NOK 1,500,000, which is more than double the average income in Norway, which is NOK 712,440 (36). Just over half of the participants reported some degree of higher education, just less than half reported their marital status as “single”.

Table 2 shows previous use of MDMA and motivation, and Table 3 shows the use of other substances. A small proportion of the sample – 10.0% – reported only one experience with MDMA, and 31.4% reported no use last year. Of the remaining, 48.3% reported MDMA use one to ten times in the past year, 41.7% reported more than ten times (see Figure 2 ). Five participants (0.8%) reported using MDMA more than 50 times over the previous year. We found no connection between frequency of use and gender (χ² = 15,600, df = 10, p = .112, Cramer’s V = .11), but there was a small positive correlation with age (r = .14, p <.001).

Over 80% reported that they wanted the same experience again as motivation for repeated use. Most of the participants used only MDMA (60.2%), whereas alcohol was the most frequent other substance together with MDMA (59.9% of those with mixed use). Simultaneous cannabis use was also frequent (38.8%), whereas other substances were used more scarcely (less than 18.2%). No gender differences were observed in concurrent drug use neither overall nor for cannabis or alcohol (p = .110 to.300). For age, there was a sharp drop-off over 45 years where almost no one reported taking other drugs besides MDMA (χ² = 16,280, df = 8, p = .039, Cramer’s V = .16). When asked about their perception of the dose based on the effects of MDMA, most respondents (95.5%) described it as moderate or high. Over 90% reported that they remembered the experience quite or very well.

Table 4 details the reported set and setting of the experience, and Table 5 reports on experiences and attitudes. Most participants used MDMA at someone else’s home (34.4%) or at home (28.3%), a total of 62.7% in a private setting. 48.8% received guidance or support, and only 5.8% were alone. Nine participants reported paying a guide, which could be indicative of a so-called “underground clinic”, meaning someone offering guidance and/or therapy as an illicit service. The vast majority regarded support or guiding as somewhat or very constructive (78.9%). A majority of 65.6% reported taking MDMA as a purely recreational activity, whereas 22.9% reported a therapeutic setting. Most participants prepared for the occasion to a large or very large extent (63.0%), and a significant portion had a clear intention to a large or very large extent (54.3%, see Figure 3 ). The sample was mixed on their report of desire for change, with the largest portion reporting neither/or (35.7%). Still, a large portion also reported integration work as part of the experience to a large or very large extent (44.1%, see Figure 4 ). A clear majority agree or strongly agree that MDMA should be used therapeutically (84.7%, M = 4.40, SD = 0.89). Participants reported a clear increase in their understanding of life events (M = 3.67, SD = 1.57), in their discovery of relational patterns (M = 4.00, SD = 1.50), and new ways of coping (M = 3.57, SD = 1.58). Participants were minimally concerned about the illegal status of the drug (M = 2.70, SD = 1.43), and merely 20 participants (3.2%) reported that their MDMA use had resulted in encounters with the police.

Table 6 shows a comparison to other experiences and persisting changes. The experience was considered, from 1-8, highly meaningful (M = 5.11, SD = 1.66), spiritual (M = 4.04, SD = 2.33), and insightful (M = 4.69, SD = 2.00), but not very challenging (M = 2.56, SD = 1.80). The most prominent persistent changes were attitudes towards death (M = 3.64, SD = 1.03), spirituality (M = 3.29, SD = 1.01), and attitudes towards nature (M = 3.09, SD = 1.13). Additionally, about one fifth of the participants rated the experience as among the top five or the single most personally meaningful, spiritual, or psychologically insightful experience (range 19-24%).

Table 7 shows the results from the four standardized questionnaires: PSI, EBI, CBQ and LPFS-BF. Respondents reported a high degree of psychological insight following the experience (PIS M = 51.29, SD = 30.24) as well as a high degree of emotional breakthrough (EBQ M = 49.83, SD = 28.69). At the same time, they reported a fairly low level of challenging experiences (CEQ M = 1.56, SD = 0.67). Physical distress was the most common challenge (M = 2.12, SD = 1.00), followed by grief (M = 1.59, SD = 0.84) and fear (M = 1.51, SD = 0.89). Participants reported positive personality changes on average, but the individual variance was high (M = 0.73, SD = 1.06).

As shown in Tables 8 and 9 , the most prevalent self-perceived or clinician-assessed diagnoses were smoking (47.5%), depression (40.5%), social anxiety (31.9%), suicidality (29.9%), and ADHD (25.4%). The mean number of diagnoses was 2.96 (SD 2.68). As displayed in Figure 5 , most of the participants (499, 82.1%) reported at least one diagnosis, whereas only 109 participants (17.9%) reported no mental disorders or substance use disorders.

Figure 6 shows the proportion of reported change for each condition, grouped into worsening (small, medium or large unwanted change), no change, or improved (small, medium or large desired change). The largest negative change was reported for psychosis of 29%, although the numbers were small (n=7). Eating disorder had a 17% negative change, whereas addiction had 12%, the remaining were all at 10% or less. The largest proportion of no change occurred for smoking (82%), chronic pain (68%), and insomnia (55%), the rest comprised less than 47%. The largest improvement was reported for PTSD (83%), depression (75%), suicidality (73%), and social anxiety (71%). The remaining reported improvements from 17% (smoking) to 61%.

As shown in Table 10 , a significant portion of participants reported no side effects from the MDMA experience (47.9%), whereas a similar portion reported some effects in the following days (42.3%). A small but notable portion reported effects from some weeks to more than a year (9.9%). The most frequent effect was sadness/dejection (30.3%), the rest were reported at lower levels (16.9% and lower, most below 10%). There were no age differences, but a complex relationship with gender appeared, suggesting that more men than women reported no adverse effects (65.3% versus 34.4%) and less effects lasting more than one year (60% versus 40%, χ² = 16,969, df = 8, p = .030). Two percent reported serious adverse effects, 4.8% sought medical help, whereas 54.8% reported no or mild effects. A majority of 57.7% reported a craving to administer the substance again, but only 5.2% reported being unsuccessful in curbing MDMA intake. Regarding acute adverse effects, 6.6% of the participants reported experiencing strong to extreme levels of fear, paranoia, bodily distress or fear of going insane as indicated by a CEQ mean score of 4–5 on at least one of the four domains.

Table 11 shows that the majority of participants reported a moderate, strong or extremely strong increased understanding of the significance of past life events during the MDMA experience (59.2%). A clear majority of 67.5% reported that they uncovered associations between current and past interpersonal relationships during the MDMA experience. As many as 92.7% of the participants reported that they discovered new or forgotten ways of dealing with difficulties and challenges during the MDMA experience.

Most participants reported on a MDMA only experience, some combined MDMA with alcohol, and some also with other substances. Overall frequency of use was low in the sense that the highest frequency category was two to five occasions both last year and lifetime use. Still, 68.6% of participants reported MDMA use within the past 12 months, and over 60% reported more than five experiences, meaning that we had an experienced sample. This finding contrasts sharply with the data published in 2024 by the Norwegian Institute of Public Health, which indicated that only 1.4% of Norwegians aged 16–64 and 3.2% of those aged 16–30 had used MDMA the past 12 months (4). This large difference is likely a reflection of the convenience sampling resulting in a non-representative sample with more consistent and dedicated users, where the national survey used a random draw from a large representative sample of Norwegians (4).

Notable distinctions exist between the administration of MDMA in clinical versus nonclinical settings, particularly regarding preparation before, support during and integration following the MDMA experience (38). But there are also similarities in the way our participants approached and structured the experience. Most participants in our survey took a moderate or high dose, and they recalled the experience well. They were generally well-prepared and approached it with clear intentions, indicating that they aimed for a “peak” experience intended to increase well-being (39). However, only a subset reported explicit therapeutic motivations, and both the reported desire for change and post-experience integration work were limited in the sample. Still, about half of the participants received guidance or support, and many reported gaining deeper insights into life events and relational patterns, as well as strategies for coping with challenges. The participants also held positive attitudes toward MDMA’s therapeutic potential. We are therefore wondering whether the label “therapeutic” is too closely tied to having mental disorders and have therefore not felt appropriate for many participants. The connection between well-defined set and setting on the one hand, including expectancy effects, and positive and negative outcomes on the other, needs further exploration. For now, we conclude that while there were some similarities, key differences also emerged between the set and setting in this survey compared to MDMA-assisted therapy in clinical trials.

Participants in our survey reported substantial improvements in PTSD following their memorable MDMA experience. This is consistent with the Phase 3 trials of MDMA-AT for PTSD (9, 10), which demonstrated a significant reduction in symptoms in the MDMA group compared to the placebo group. Notably, our participants also reported significant improvements in depression, both in the sample as a whole and in a subset with depression (40). One of the Phase 3 trials of MDMA-AT for PTSD found a statistically significant reduction in depression symptoms (9), and the first proof-of-principle study on MDMA-AT for major depressive disorder was recently completed in Norway (41). Interestingly, the three conditions with the greatest improvements in this survey—PTSD, depression, and suicidality—mirror exactly those in our previous survey on classic psychedelics (28). The reason for this remains unclear, though overlap between study populations may be a factor.

The explanations for the corresponding results can be manifold. One could be that the drug targets specific neural and psychological mechanisms that lead to improvements in the conditions. Another could be that our sample has to a large degree applied the same therapeutic mindset and framing that also characterizes clinical studies. Most likely we are seeing a combination of the two.

The results on personality changes following administration of psilocybin are mixed (42), but on MDMA research is mostly lacking all together. A comparison of personality traits between groups of “hard” and “non-hard” drug users found differences in trait composition but did not examine effects on personality traits following MDMA use (43). Wagner et al. (44) found an increase in openness and a decrease in neuroticism in connection with PTSD treatment, whereas a meta-analysis found increased openness, but also more adverse effects connected to higher neuroticism (11). We measured levels of personality functioning, which is connected to higher neuroticism, but is a more general measure of overall functioning. Our results indicate that recreational MDMA use may be connected to improved overall functioning and therefore better mental health. The connection between level of personality functioning, diagnoses, and well-being is complex and needs further exploration, but we want to argue that we should move beyond symptom load and categorical diagnoses when measuring possible beneficial effects of MDMA. Our results may also inform future research on MDMA-assisted personality disorder treatment (45).

Our participants most frequently reported adverse effects were sadness/dejection (30.3%), anxiety/nervousness (16.9%), sleeplessness (15.3%) and difficulties concentrating (15%). This further supports the evidence related to negative effects on mood and cognition in the days following dosing, also known as ‘Blue Mondays’. This has been found for recreational MDMA users (23) and in participants in controlled trials (22, 24). Overall, our participants reported relatively few and quite short-lived adverse effects, and very few reported long-lasting adverse effects. This result is in line with at least one previous survey on recreational MDMA use (5). We would also like to note that participants in the classic psychedelics study reported significantly higher levels of psychological challenges on the CEQ than our participants did (5.99 versus 2,56; 28). MDMA experiences therefore seem to be far less challenging than experiences with psychedelics.

The observed low degree of challenging experiences may be, in part, a function of our sampling methodology. It is plausible that individuals who had particularly negative or traumatic experiences with MDMA were less inclined to participate in a survey of this nature, leading to a potential self-selection bias. It is also important to consider that the concept of a “meaningful experience” does not preclude it from being psychologically challenging, and that difficult experiences can often be a crucial component of a therapeutic process. Furthermore, the high reported rates of preparation and integration work within our sample may reflect a greater awareness of harm-reduction practices, which itself could be a characteristic of the self-selecting population. Consequently, our findings may be more indicative of the MDMA experience when it is approached with a conscientious focus on set and setting, rather than a representation of a more general population. This perspective, however, provides valuable insights into how therapeutic benefits might be optimized in non-clinical contexts.

The present study has several limitations that should be noted. First of all, a cross-sectional study like ours is not suited as a basis for causal conclusions. Second, the retrospective design makes the data susceptible to recall bias. Most participants reported that they remember the experience well, but we do not know how accurate this recall is. A substantial majority reported use of MDMA on several occasions, and it can therefore be hard to separate negative and positive effects experienced in other sessions from the single most memorable experience. Third, a response bias is to be expected, both because of the self-report format and because of participant selection. Self-report is susceptible to socially desirable responding influenced by media coverage, peer influence (we cannot know if participants filled in the form alone), from various degrees of prior knowledge of the subject, and more. Especially regarding self-reported diagnoses that are not reported as set by a clinician, we need to consider the possibility that participants feel they have a diagnosis although the criteria may not be fulfilled. In addition, we should expect that we have an overrepresentation of responders with positive experiences and attitudes. Given that we recruited from web sites that provide neutral information about drugs and drug use, we may also have a selection of participants that are above average in knowledge and curiosity than a representative sample would be. Those with negative, and perhaps only negative experiences with MDMA, are less likely to participate as they might have shunned the whole topic. Furthermore, our participant sample may not be representative for the average MDMA user, especially in terms of its high level of education and income. Finally, and as a summary of the previous points, more research is needed into less privileged and less positively inclined participants to get a more complete picture of the possible negative effects of recreational MDMA use.