Abstract
Background:
Psilocybin, a classic hallucinogen, may eventually be approved by the United States Food and Drug Administration for treatment-resistant depression. However, we are aware of only one published national survey of American psychiatrists regarding their opinions about hallucinogens and hallucinogen-assisted therapy, conducted by our group in 2016. Here, we report a repeat survey, using virtually identical methods, assessing whether American psychiatrists display greater optimism about the therapeutic use of hallucinogens in 2022–23.
Methods:
We e-mailed our survey instrument to 1,000 randomly selected American Psychiatric Association members—250 resident-fellows and 750 attending psychiatrists—in late 2022 and early 2023. We calculated descriptive statistics and used a non-parametric trend test to compare the current survey responses with those from 2016. We also constructed a multivariate logistic regression model to assess attributes of respondents that predicted moderate/strong agreement with plans to incorporate hallucinogen-assisted therapy into their own practice.
Results:
The response rate was 13.1% (N = 131). Respondents were demographically similar to the 2016 respondents. A majority moderately/strongly believed that hallucinogens show promise in treating psychiatric conditions (80.9%) and substance use disorders (SUDs) (60.8%). Large majorities also moderately/strongly supported research into hallucinogens' therapeutic potential for psychiatric conditions (93.9%) and SUDs (88.6%), as well as federal funding of associated clinical trials (84.7% and 80.9%, respectively). Comparisons to 2016 showed significantly increased optimism regarding the therapeutic promise of hallucinogens and decreased concern about risks, with 50.4% of respondents reporting moderate/strong intentions to incorporate hallucinogen-assisted therapy into their practice.
Conclusions:
Our data reveal a striking positive shift in attitudes toward the therapeutic potential of hallucinogens among American psychiatrists since 2016, with a majority of responding psychiatrists planning to incorporate hallucinogen-assisted therapy into their practice if regulatory approval is granted.
Keywords: psychedelics, psychedelic assisted therapy, hallucinogen, psychiatrist, survey
Introduction
Classic hallucinogens, sometimes referred to as “classic psychedelics,” are compounds such as psilocybin, lysergic acid (LSD), and mescaline that primarily exert their psychoactive effects via 5-HT2A receptor agonism.1 Despite accelerating research into therapeutic applications of classic hallucinogens, including the initiation of phase 3 trials assessing the efficacy of psilocybin-assisted therapy for treatment-resistant depression in 2023,2 data are limited on American psychiatrists' current attitudes regarding these drugs and their therapeutic potential.
It is of interest to gauge these attitudes, given the possibility that psilocybin could be approved by the United States (US) Food and Drug Administration (FDA) in late 2025.3
To our knowledge, the only published national survey querying American psychiatrists about classic hallucinogens was conducted by members of our group, with data collected in 2016 and published in 2018.4 At that time, we found that 65% of respondents moderately/strongly agreed that use of classic hallucinogens increases the risk for subsequent psychiatric disorders, whereas 48% moderately/strongly agreed that their use increases the risk for long-term cognitive impairment.
Fewer than half (43%) moderately/strongly agreed that classic hallucinogens show promise in treating psychiatric disorders. Respondents who were younger, men, and in training reported less concern about the risks of hallucinogens and greater optimism about their therapeutic potential.
A 2021 survey of psychiatrists attending talks on hallucinogens at national conferences in the United States, performed by one of the authors, found that increased belief in hallucinogens' treatment potential was associated with working primarily in research, scoring higher on a hallucinogens knowledge test, and reporting less concern about hallucinogens' addictive potential.5
Given accumulating data supporting the therapeutic potential of classic hallucinogens6 and possibly increasing cultural acceptance of these drugs, as evidenced by rising non-medical use of them,7,8 we conducted a repeat national survey of American psychiatrists' opinions about classic hallucinogens using methods virtually identical to those of the 2016 survey. We hypothesized that respondents from the current survey would be more optimistic about the therapeutic potential of hallucinogens and less concerned about their risks than participants in the 2016 survey.
Methods
Survey instrument
We assessed attitudes toward classic hallucinogens among American psychiatrists using an anonymous 24-item Internet-based survey. Though the term psychedelic is increasingly being used, we used the term hallucinogen in our instrument to be consistent with language in our previous survey and to allow for more direct comparisons with its results.
Participants were also instructed to answer regarding classic hallucinogens only, according to this language: “The following items will assess your attitudes towards classic hallucinogens (such as Ayahuasca, Dimethyltryptamine, LSD, psilocybin, etc.). Please give your level of agreement or disagreement with each statement. For purposes of this study, do not consider non-classic hallucinogens such as ketamine, MDMA (ecstasy), or phencyclidine.”
The previous national survey in 2016 included 14 items, all of which were included in the present survey. These included seven demographic questions about respondents' (1) age, (2) gender, (3) level of training, (4) date of completion of training if applicable, (5) primary daily practice activity (clinical care, research, or administration), (6) primary treatment approach if applicable (biological or psychotherapeutic), and (7) the number of peer-reviewed scientific articles that the respondent had published.
Additional demographic questions added for the current version of the survey covered race/ethnicity, territory or state of residence, and subspecialty training. The current survey also included questions from the original survey asking about respondents' opinions on whether use of classic hallucinogens (1) increases the risk for subsequent psychiatric disorders; (2) increases the risk of long-term cognitive impairment; (3) should be illegal for recreational/non-medical purposes; (4) is unsafe even under medical supervision; (5) shows promise in the treatment of psychiatric disorders; (6) can improve outcomes if used in combination with psychotherapy; and (7) deserves further research as potential treatment for psychiatric disorders.
Participants registered their agreement or disagreement with these statements on a five-point Likert scale, with options ranging from “strongly disagree” to “strongly agree.”
The following statements, not included in the 2016 instrument, were added: (1) medical use of hallucinogens should be legalized; (2) hallucinogens show promise in treating substance use disorders (SUDs); (3) the federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of psychiatric disorders; (4) further research should be conducted on hallucinogens to assess their potential as treatments for SUDs; (5) the federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of SUDs; and (6) I will incorporate hallucinogen-assisted therapy into my own practice if it gains federal regulatory approval as a medical treatment. The same five-point Likert scale was provided for response options.
Study sample
Due to the potential for biasing the sample from our 2016 study (i.e., perhaps prior participants might have developed more interest in therapeutic applications of hallucinogens after participating than they would have otherwise), we opted to disseminate the current survey to a new sample of randomly selected psychiatrists. We used a random number generator to select 1,000 American psychiatrists from the American Psychiatric Association's (APA's) online member directory.
Of these, 250 were selected from the 5,044 resident-fellow members and 750 from the other 22,163 psychiatrist members (general members, life members, fellows, life fellows, distinguished fellows, and distinguished life fellows).9 Members based outside the United States were excluded. We selected the participants from the directory and emailed survey invitations to them between August 30, 2022, and March 21, 2023. We then sent reminder e-mails to all participants 2 and 4 weeks after the initial invitation.
To estimate our ability to detect a difference between the proportion observed in the response to a given question on our survey and the true proportion among APA psychiatrists as a whole, we assumed for purposes of calculation that we would achieve the same response rate in 2023 as in the 2016 study (i.e., 324/1000). With this assumed response rate, we would have >80% power (at alpha = 0.05) to detect a difference of more than 0.07 between a given observed proportion and the true proportion (i.e., a difference of 50% observed vs. 43% true).
Data analysis
Study data were collected and managed using REDCap electronic data capture tools hosted at Cleveland Clinic10,11 and Stata version 15.1 (StataCorp, College Station, TX) to perform statistical analyses. We first calculated summary statistics for each survey item. Fisher's exact test was used to analyze gender differences between the two survey administrations.
We checked for associations between some of the demographic variables cited earlier and some opinion variables using Cuzick's nonparametric trend test12 that incorporated all five levels of Likert-scale responses. Comparisons of results between the 2016 survey (which had a sample size of 324) and the current survey were also analyzed in this manner.
We also constructed a multivariate logistic regression model with a dependent variable of moderate/strong agreement with the statement “I will incorporate hallucinogen-assisted therapy into my own practice if it gains federal regulatory approval as a medical treatment.” We chose independent variables that included demographic measures and responses to some opinion items.
These included age, gender, and attending status, based on our previous findings that these were associated with attitudes toward hallucinogens among psychiatrists. Race (White vs. other races/ethnicities) was chosen due to some epidemiological data in the general population, indicating that there may be racial differences in risk perception of classic hallucinogens.13
Primarily daily activity of providing clinical care was also incorporated to account for respondents possibly unable to incorporate hallucinogen therapy into their practice due to seeing a few or no patients. Practicing versus not practicing in the West region of the United States (defined by the U.S. census bureau as Alaska, California, Colorado, Hawaii, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming14) was incorporated into the model given a recent number of significant changes in that region regarding the legal status of hallucinogens, including decriminalization of possession of all illicit drugs, legalization of supervised psilocybin use in Oregon,15 and decriminalization of psilocybin possession and legalization of supervised psilocybin use in Colorado.16
Although some Midwestern and East Coast cities such as Ann Arbor, Michigan17 and Washington, D.C.18 have also decriminalized hallucinogenic plants and fungi, these efforts have not yet reached the same scale as in the Western United States. We also incorporated the survey items on concerns about hallucinogens increasing risk for psychiatric disorders and cognitive impairment and belief in hallucinogens showing promise in treating psychiatric disorders. There was no significant collinearity of independent model variables.
No statistical method was employed to substitute for missing data. Tables list total N for each calculation in question for clarity. Statistical significance was set at p < 0.05, two-tailed, for all statistical tests. In evaluating our findings, however, it is important to note that this study employed multiple statistical comparisons, which increases the likelihood of type I statistical errors.
Although methods to correct for this exist, such as Bonferroni correction, they can inflate type II error rates.19 Therefore, in line with advice of some prior authorities,20,21 we present our findings without correction for multiple comparisons. We caution readers to consider this when interpreting them.
Ethics approval
This study was approved by the Cleveland Clinic Institutional Review Board.
Results
Participant characteristics
The response rate was 13.1% (N = 131). Mean (standard deviation) age was 46.9 (15.3) years; 61.2% of respondents were men; 70.2% were white; and 70.2% were attending psychiatrists. The mean year of residency completion was 2007.1 (16.5); 80.3% of respondents performed primarily clinical work; and 71.4% reported a biological treatment orientation. Respondents were demographically similar to respondents of the 2016 survey (N = 324). Further details about participant characteristics are detailed in Table 1.
Table 1.
Demographic Features of Survey Respondents for 2016 and 2022–2023 Samples
| Characteristic | 2016 sample n/N (%) | 2022–2023 sample n/N (%) |
|---|---|---|
| Age (years, mean ± SD) | 41–50a (N = 318) |
46.9 ± 15.3 (N = 130) |
| Gender | ||
| Woman | 151/318 (47.5) | 50/129 (38.8) |
| Man | 167/318 (52.5) | 79/129 (61.2) |
| Race/ethnicityb | ||
| African American/Black | N/a | 7/131 (5.3) |
| Alaskan Native/American Indian/Native American | N/a | 1/131 (0.8) |
| Asian | N/a | 19/131 (14.5) |
| Caucasian/White | N/a | 92/131 (70.2) |
| Hispanic | N/a | 10/131 (7.6) |
| Native Hawaiian/Other Pacific Islander | N/a | 2/131 (1.5) |
| Other | N/a | 5/131 (3.8) |
| Region of residencec | ||
| Midwest | N/a | 17/102 (16.7) |
| Northeast | N/a | 30/102 (29.4) |
| Southeast | N/a | 23/102 (22.6) |
| Southwest | N/a | 10/102 (9.8) |
| West | N/a | 22/102 (21.6) |
| Year of residency completion (mean ± SD) | 1990sc | 2007.1 ± 16.5 |
| Training level | ||
| Attending | 230/323 (71.2) | 92/131 (70.2) |
| Fellow | 17/323 (5.3) | 9/131 (6.9) |
| Resident | 76/323 (23.5) | 30/131 (22.9) |
| Fellowships completed or in progressb | ||
| Child | N/a | 25/131 (19.1) |
| Consult-Liaison | N/a | 9/131 (6.9) |
| Addiction | N/a | 8/131 (6.1) |
| Other | N/a | 21/131 (16.0) |
| None | N/a | 76/131 (58.0) |
| Performs primarily clinical care | 272/319 (85.3) | 109/131 (83.2) |
| Biological treatment orientation | 243/312 (77.9) | 90/126 (71.4) |
| Published any peer-reviewed articles | 191/323 (59.1) | 76/124 (61.3) |
Data for these variables were collected in 10-year increments in 2016 survey administration, median value reported.
Total percentage sums to >100 due to ability to select multiple options.
Data available for only 102 participants due to question being added after survey initiation.
N/a, not available due to data not being collected in 2016; SD, standard deviation.
2022–2023 respondent opinions about hallucinogens and hallucinogen-assisted therapy
A significant majority of respondents moderately/strongly believed that hallucinogens show promise in treating psychiatric conditions, with a smaller majority having similar beliefs about therapeutic promise for SUDs (Table 2). The difference between responses for general psychiatric conditions as opposed to SUDs was statistically significant (80.9% [106/131] vs. 60.8% [79/130] moderate/strong belief, p < 0.001 by nonparametric trend test).
Table 2.
Respondent Agreement with Opinion Statements for 2022–2023 Sample
| Moderately or strongly disagree n/N (%) | Neutral n/N (%) | Moderately or strongly agree n/N (%) | |
|---|---|---|---|
| Statement | |||
| The use of hallucinogens increases the risk for subsequent psychiatric disorders. | 51/130 (39.2) | 31/130 (23.9) | 48/130 (36.9) |
| The use of hallucinogens increases the risk for long-term cognitive impairment. | 63/130 (48.5) | 39/130 (30.0) | 28/130 (21.5) |
| Hallucinogens should be illegal to possess or use recreationally/non-medically. | 75/131 (57.3) | 16/131 (12.2) | 40/131 (30.5) |
| Hallucinogens are unsafe to use, even under medical supervision. | 107/131 (81.7) | 11/131 (8.4) | 13/131 (9.9) |
| Medical use of hallucinogens should be legalized. | 22/130 (16.9) | 14/130 (10.8) | 94/130 (72.3) |
| Hallucinogens show promise in treating psychiatric disorders. | 10/131 (7.6) | 15/131 (11.5) | 106/131 (80.9) |
| Hallucinogens show promise in treating SUDs. | 20/130 (15.4) | 31/130 (23.9) | 79/130 (60.8) |
| The use of hallucinogens during psychotherapy may improve outcomes. | 11/131 (8.4) | 24/131 (18.3) | 96/131 (73.3) |
| Further research should be conducted on hallucinogens to assess their potential as treatments for psychiatric disorders. | 6/131 (4.6) | 2/131 (1.5) | 123/131 (93.9) |
| The federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of psychiatric disorders. | 8/131 (6.1) | 12/131 (9.2) | 111/131 (84.7) |
| Further research should be conducted on hallucinogens to assess their potential as treatments for SUDs. | 9/131 (6.9) | 6/131 (4.6) | 116/131 (88.6) |
| The federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of SUDs. | 11/131 (8.4) | 14/131 (10.7) | 106/131 (80.9) |
| I will incorporate hallucinogen-assisted therapy into my own practice if it gains federal regulatory approval as a medical treatment. | 31/129 (24.0) | 33/129 (25.6) | 65/129 (50.4) |
SUDs, substance use disorders.
A substantial majority also expressed beliefs that use of hallucinogens during psychotherapy may improve outcomes. Only a minority of respondents moderately/strongly believed that hallucinogens increase the risk for subsequent psychiatric disorders; increase the risk of long-term cognitive impairment; are unsafe to use, even under medical supervision; or should be illegal to possess or use recreationally/non-medically.
By contrast, substantial majorities of respondents moderately/strongly favored legalization of hallucinogens for medical use; together with further research and increased federal funding directed at the therapeutic potential of hallucinogens for psychiatric conditions and SUDs. Finally, about half of the respondents reported moderate/strong intentions to incorporate hallucinogen-assisted therapy into their own practice if federal regulatory approval is granted.
Analyses of 2022–2023 data by respondent gender, age, and training status
Nonparametric trend testing incorporating all five levels of Likert-scale responses for survey items by gender identified only one statistically significant difference, with women showing higher levels of belief that hallucinogens increased the risk for long-term cognitive impairment (Supplementary Table S1). No significant differences on response items were noted for training status (Supplementary Table S2).
Analysis of item response by age groups (Table 3) revealed several significant differences, with older participants tending to show somewhat greater reservations and less optimism about hallucinogens on these items.
Table 3.
Opinions Regarding Hallucinogens and Hallucinogen-Assisted Therapy by Age for 2022–2023 Sample
| Statement |
Moderately or strongly agree
|
p a | |
|---|---|---|---|
| Age ≤40 n/N (%) | Age >40 n/N (%) | ||
| The use of hallucinogens increases the risk for subsequent psychiatric disorders. Total N = 129 | 22/60 (36.7) | 26/69 (37.7) | 0.362 |
| The use of hallucinogens increases the risk for long-term cognitive impairment. Total N = 129 | 11/60 (18.3) | 16/69 (23.2) | 0.718 |
| Hallucinogens should be illegal to possess or use recreationally/non-medically. Total N = 130 | 13/60 (21.7) | 26/70 (37.1) | 0.097 |
| Hallucinogens are unsafe to use, even under medical supervision. Total N = 130 | 3/60 (5.0) | 10/70 (14.3) | 0.030 |
| Medical use of hallucinogens should be legalized. Total N = 129 | 48/59 (81.4) | 45/70 (64.3) | 0.178 |
| Hallucinogens show promise in treating psychiatric disorders. Total N = 130 | 52/60 (86.7) | 53/70 (75.7) | 0.348 |
| Hallucinogens show promise in treating SUDs. Total N = 129 | 41/60 (68.3) | 37/69 (53.6) | 0.030 |
| The use of hallucinogens during psychotherapy may improve outcomes. Total N = 130 | 50/60 (83.3) | 45/70 (64.3) | 0.003 |
| Further research should be conducted on hallucinogens to assess their potential as treatments for psychiatric disorders. Total N = 130 | 58/60 (96.7) | 64/70 (91.4) | 0.087 |
| The federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of psychiatric disorders. Total N = 130 | 52/60 (86.7) | 58/70 (82.9) | 0.160 |
| Further research should be conducted on hallucinogens to assess their potential as treatments for SUDs. Total N = 130 | 55/60 (91.7) | 60/70 (85.7) | 0.011 |
| The federal government should fund clinical trials investigating the efficacy of hallucinogens for treatment of SUDs. Total N = 130 | 52/60 (86.7) | 53/70 (75.7) | 0.035 |
| I will incorporate hallucinogen-assisted therapy into my own practice if it gains federal regulatory approval as a medical treatment. Total N = 128 | 35/60 (58.3) | 30/68 (44.1) | 0.008 |
Significance calculated by Cuzick's nonparametric trend test incorporating all five levels of Likert scale responses using age as continuous variable. Bolded font indicates statistical significance at 0.05 level.
Analyses of responses by year of data collection (2016 vs. 2022–2023)
Looking at comparisons of the seven items common to the 2016 and 2022–2023 surveys according to survey year (Table 4), we found highly significant differences on all comparisons, with 2022–2023 respondents reporting less concern about the potential risks of hallucinogens, stronger belief in their therapeutic potential, less support for non-medical use of hallucinogens being illegal, and stronger support for research into the potential therapeutic applications of hallucinogens for psychiatric disorders.
Table 4.
Respondent Moderate/Strong Agreement with Opinion Statements for 2016 and 2022–2023 Samples
| Statement | Moderate/strong agreement 2016 sample n/N (%) | Moderate/strong agreement 2022–2023 sample n/N (%) | p a |
|---|---|---|---|
| The use of hallucinogens increases the risk for subsequent psychiatric disorders. Total N = 451 | 208/321 (64.8) | 48/130 (36.9) | <0.0001 |
| The use of hallucinogens increases the risk for long-term cognitive impairment. Total N = 451 | 154/321 (48.0) | 28/130 (21.5) | <0.0001 |
| Hallucinogens should be illegal to possess or use recreationally/non-medically. Total N = 452 | 174/321 (54.2) | 40/131 (30.5) | <0.0001 |
| Hallucinogens are unsafe to use, even under medical supervision. Total N = 452 | 79/321 (24.6) | 13/131 (9.9) | <0.0001 |
| Hallucinogens show promise in treating psychiatric disorders. Total N = 452 | 136/321 (42.4) | 106/131 (80.9) | <0.0001 |
| The use of hallucinogens during psychotherapy may improve outcomes. Total N = 451 | 92/320 (28.8) | 96/131 (73.3) | <0.0001 |
| Further research should be conducted on hallucinogens to assess their potential as treatments for psychiatric disorders. Total N = 453 | 260/322 (80.4) | 123/131 (93.9) | <0.0001 |
Significance calculated by Cuzick's nonparametric trend test incorporating all five levels of Likert scale responses. Bolded font indicates statistical significance at 0.05 level.
Of note, compared with the 2016 sample, the 2022–2023 sample had a non-significantly larger proportion of men, a demographic that was found to hold more positive views toward hallucinogens in our previous survey. Though this difference was not statistically significant (61.2% [79/129] vs. 52.5% [167/318]; p = 0.095 by Fisher's exact, two tailed), a 10% or more relative difference between groups for a variable can still potentially cause confounding.22
Therefore, we conducted additional analyses of responses based on survey year in the subgroups of men and women to assess whether gender influences these differences (Supplementary Tables S3 and S4). However, when looking at each gender individually, all differences remained statistically significant and were oriented in the same direction as the analysis of the entire sample.
Multivariable logistic regression model for intentions to incorporate hallucinogen-assisted therapy into practice
Table 5 details the findings of a multivariable logistic regression model assessing moderate/strong intentions to incorporate hallucinogen-assisted therapy into one's own psychiatric practice should hallucinogens gain regulatory approval for this purpose. The only statistically significant variable identified was level of belief in the promise of hallucinogens to treat psychiatric disorders (odds ratio 4.19; 95% confidence interval [CI] 1.73–10.15, p = 0.001).
Table 5.
Multivariable Logistic Regression Assessing Moderate/Strong Agreement with Plans to Incorporate Hallucinogen-Assisted Therapy into Practice
| Variable a | Odds ratio | CI | p |
|---|---|---|---|
| Age | 1.00 | 0.95–1.05 | 0.970 |
| Gender | 1.13 | 0.39–3.31 | 0.825 |
| Race: White | 1.14 | 0.37–3.47 | 0.819 |
| Attending status | 0.26 | 0.06–1.24 | 0.092 |
| Practices in Western United States | 3.52 | 0.80–15.51 | 0.096 |
| Daily activity primarily clinical | 2.22 | 0.44–11.09 | 0.332 |
| Concern about hallucinogens increasing risk for psychiatric disorders | 0.87 | 0.46–1.66 | 0.679 |
| Concern about hallucinogens increasing risk for cognitive impairment | 0.68 | 0.34–1.34 | 0.263 |
| Belief that hallucinogens show promise in treating psychiatric disorders | 4.19 | 1.73–10.15 | 0.001 |
Total N = 97. Bolded font indicates statistical significance at 0.05 level.
CI, Confidence interval.
Discussion
We conducted an online survey of American psychiatrists assessing their attitudes regarding the safety and potential therapeutic promise of hallucinogens, using questions identical to those that we used on a similar Internet survey conducted in 2016.4
The most striking finding of our study was that respondents displayed significantly lower levels of concern about the risks of hallucinogens and significantly higher levels of enthusiasm about the potential promise of hallucinogen-assisted therapy as compared with respondents in 2016. Substantial majorities of respondents favored further research on the therapeutic potential of hallucinogens and federal funding for such studies.
About half of the respondents expressed moderate/strong intentions to incorporate hallucinogen-assisted therapy into their practice if regulatory approval is granted. This suggests a substantial level of enthusiasm, given the logistical demands of delivering such therapy, and questions about potential reimbursement.23 Of note, in a recent survey of therapists, 75% of respondents reported that they would be unlikely to administer hallucinogen-assisted therapy if doing so reduced their income.24
Importantly, respondents expressed significantly stronger beliefs in the therapeutic potential of hallucinogens in psychiatric conditions than SUDs. While clinical trials suggest that psilocybin25,26 and LSD27 hold promise for SUDs, fewer contemporary trials have explored this area of therapeutic application in comparison to psychiatric conditions.
This limited amount of evidence might help explain this difference in opinions. Another consideration is that concerns about hallucinogens' addictive potential may be influencing psychiatrists' beliefs about treatment potential for SUDs. Though we did not assess concerns regarding the addictive potential of hallucinogens in this survey, a previous study of psychiatrists attending presentations about hallucinogens at professional conferences in the United States found that 28% expressed concern about this issue.5
That study found that concern about addictive potential was negatively associated with support for the belief that hallucinogens can treat SUDs, while being a researcher and having higher performance on a hallucinogen knowledge test were positively associated with support for this belief.
A minority of respondents believed that the use of hallucinogens increases the risk for subsequent psychiatric disorders. This belief has only limited support in literature. Although cases of first-time mania and psychosis have been reported in some hallucinogen users, population-level studies have failed to find associations between hallucinogen use and mental illness.28–30
A minority of respondents also believed that hallucinogens increase the risk for long-term cognitive impairment. Again, this belief lacks support from published investigations, in that studies of ritualistic peyote users,31 ayahuasca users,32 and participants in a clinical trial of psilocybin33 have found no evidence of lasting cognitive impairment following hallucinogen use.
Fewer than 10% of respondents believed that hallucinogens cannot be safely administered under medical supervision, despite a growing body of research suggesting that these drugs can be used safely in medical settings.1 Respondents demonstrated significant support for medical legalization of hallucinogens, despite their current classification by the Drug Enforcement Administration as Schedule 1 drugs “with no currently accepted medical use and a high potential for abuse.34” A majority also disagreed that hallucinogens should be illegal to possess for non-medical use.
We found a few significant differences in responses to survey items when comparing demographic subgroups of respondents, save for the fact that older respondents generally showed greater apprehensions about the risk/benefit ratio of hallucinogen-assisted therapy. This suggests that younger psychiatrists could become the core hallucinogen-assisted therapy providers within the field should regulatory approval be granted.
It will likely be of value to track the attitudes of psychiatrists, both in the United States and in other countries, with subsequent similar surveys as further studies of hallucinogens continue to appear. Subsequent surveys should explore respondents' concerns about the addictive potential of hallucinogens and other aspects of patient safety, as well as financial and logistical aspects of delivering hallucinogen-based treatments.
Limitations
The primary limitation of this study was its low response rate with the consequent risk of selection bias. For example, psychiatrists with more favorable views toward hallucinogens might have been more likely to respond than those who were more skeptical. Thus, one should exercise caution in attempting to generalize the results of the present survey to American psychiatrists as a whole.
Nevertheless, if such selection bias did occur, this would seem less likely to threaten the validity of differences between subgroups within the sample unless such bias were differentially associated with particular subgroups (e.g., if, say, older psychiatrists favorable to hallucinogens were more motivated to respond than older psychiatrists as a whole, whereas younger psychiatrists equally favorable to hallucinogens were not more motivated to respond than younger psychiatrists as a whole).
The comparisons between the current survey and the 2016 survey also seem unlikely to be seriously affected by selection bias, since the factors motivating participants to respond were likely similar in the surveys of both time points. Again, the validity of these comparisons would be threatened only if there were differential bias between the 2016 and 2022–2023 groups (e.g., if psychiatrists favorable to hallucinogens were more likely to respond than psychiatrists as a whole in 2016, but psychiatrists equally favorable to hallucinogens were not more likely to respond than psychiatrists as a whole in 2022–2023).
To reduce the chance of selection bias related to an increased or decreased desire to participate in the current survey among 2016 survey participants, we chose to email invitations for the 2022–2023 survey to a new sample of randomly selected American psychiatrists from the APA's directory. Due to the anonymous nature of these surveys, we were not able to directly determine whether some individuals participated in both.
While this is possible, the number of individuals who may have done so is likely very small given: (1) the small size of the 2016 survey's participant sample (N = 324) compared with the 27,207 eligible APA members from which we selected our sample of 1,000 to send survey invitations to in 2022–2023 and (2) the fact that resident/fellow participants of the 2022–2023 survey were unlikely to be in psychiatry and therefore unlikely to be an APA member eligible for receiving a survey invitation in 2016.
Another important consideration is that participants' knowledge of psychopharmacological classifications of hallucinogens may have been limited. Though examples of classic hallucinogens were provided in the survey instructions, previous research indicates that psychiatrists have varying degrees of familiarity with particular hallucinogens,35 which could have produced variability in responses due to differing interpretations of what constitutes a classic hallucinogen.
Finally, the sample from the current survey administration (N = 131) is smaller than that of the 2016 administration, reducing our power to detect differences, especially when comparing subgroups within the 2022–2023 sample. To illustrate this limitation with a specific example, we found in the 2016 study that men were more significantly likely than women to strongly/moderately agree that “hallucinogens show promise in treating psychiatric disorders” (56/150 [37.3%] of women vs. 81/168 [48.2%] of men).
In the 2022–2023 study, we failed to find such a gender difference, with 41 out of 50 (82.0%) of women versus 63 out of 79 (79.8%) of men expressing strong/moderate agreement on this question—a difference of 0.022 in favor of women. However, when evaluating the magnitude of the difference between genders that we can exclude in the 2022–2023 study, using a statistical test for non-equivalence36,37 we found that we cannot exclude the possibility that the true difference between the genders could be as great as 0.096 in favor of men (in other words, the probability is <5% that men exceed women by more than 0.096 on this question). As this example shows, findings such as this in the 2022–2023 sample have substantial CIs that must be considered when interpreting the results.
Conclusions
In a survey of randomly selected American psychiatrists in 2022–2023, we found significantly more positive attitudes regarding the therapeutic potential of hallucinogens, and significantly lower concern about the risks of these drugs as compared with results obtained in 2016.
The 2022–2023 respondents also more strongly favored legalization of hallucinogens for medical use, further research into therapeutic applications of hallucinogens for psychiatric disorders and SUDs, and increased federal funding for associated clinical trials, while showing less support for non-medical use of hallucinogens being illegal.
Finally, about half of 2022–23 respondents expressed moderate/strong intent to incorporate hallucinogen-assisted therapy into their practice, suggesting that hallucinogens are likely to be welcomed into the American psychiatrists' armamentarium if regulatory approval is granted for their use as medicines.
Authors' Contributions
The authors confirm contribution to the article as follows: study conception and design: B.S.B., W.O.S., J.W., and H.G.P.; data collection: M.A., D.B., J.O., and C.R.; analysis and interpretation of results: B.S.B. and H.G.P.; draft article preparation: B.S.B., J.W., and M.A. All authors reviewed the results and approved the final version of the article.
Author Disclosure Statement
B.S.B. holds stock options in CB Therapeutics. He also serves on advisory boards for CB Therapeutics and Compass Pathways. He receives monetary compensation from DynaMed Plus (EBSCO Industries, Inc.) for editorial work and from Cerebral and Janssen Pharmaceuticals for consulting services. B.S.B. receives research support from MindMed. W.O.S. serves on the scientific advisory boards for Bexson Biomedical, Inc., and People Science, Inc., and holds stock options in both companies. The other authors declare no conflicts of interest.
Funding Information
No funding was received for this article.
Supplementary Material
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