Full Terms & Conditions of access and use can be found at
Journal of Psychoactive Drugs
ISSN: 0279-1072 (Print) 2159-9777 (Online) Journal homepage: https://www.tandfonline.com/loi/ujpd20
Sub-Acute Effects of Psilocybin on Empathy,
Creative Thinking, and Subjective Well-Being
Natasha L. Mason, Elisabeth Mischler, Malin V. Uthaug & Kim P. C. Kuypers
To cite this article: Natasha L. Mason, Elisabeth Mischler, Malin V. Uthaug & Kim P. C. Kuypers
(2019): Sub-Acute Effects of Psilocybin on Empathy, Creative Thinking, and Subjective Well-Being,
Journal of Psychoactive Drugs
To link to this article: https://doi.org/10.1080/02791072.2019.1580804
© 2019 The Author(s). Published with
license by Taylor & Francis Group, LLC
Published online: 26 Feb 2019.
Submit your article to this journal
View Crossmark data
Sub-Acute Effects of Psilocybin on Empathy, Creative Thinking, and Subjective
Natasha L. Mason, M.Sc., Ph.D.
, Elisabeth Mischler, Ph.D.
, Malin V. Uthaug, M.Sc., Ph.D.
and Kim P. C. Kuypers, Ph.D.
Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The
Central Customs Authority, Centre of Education and Science, Cologne, Germany
Creative thinking and empathy are crucial for everyday interactions and subjective well-being.
This is emphasized by studies showing a reduction in these skills in populations where social
interaction and subjective well-being are significantly compromised (e.g., depression). Anecdotal
reports and recent studies suggest that a single administration of psilocybin can enhance such
processes and could therefore be a potential treatment. However, it has yet to be assessed
whether effects outlast acute intoxication. The present study aimed to assess the sub-acute
effects of psilocybin on creative thinking, empathy, and well-being. Participants attending
a psilocybin retreat completed tests of creative (convergent and divergent) thinking and empathy,
and the satisfaction with life scale on three occasions: before ingesting psilocybin (N= 55), the
morning after (N= 50), and seven days after (N= 22). Results indicated that psilocybin enhanced
divergent thinking and emotional empathy the morning after use. Enhancements in convergent
thinking, valence-specific emotional empathy, and well-being persisted seven days after use. Sub-
acute changes in empathy correlated with changes in well-being. The study demonstrates that
a single administration of psilocybin in a social setting may be associated with sub-acute
enhancement of creative thinking, empathy, and subjective well-being. Future research should
test whether these effects contribute to the therapeutic effects in clinical populations.
Received 23 October 2018
Accepted 18 January 2019
thinking; empathy; life
Creativity and empathy are crucial for everyday inter-
actions and cooperation, allowing us to adapt to an
ever-changing environment, and motivating our proso-
cial behaviors (Decety et al. 2016). Interestingly, they
have been found to be positively related (Carlozzi et al.
1995), and it has been suggested that creative, flexible
thinking is a prerequisite for empathy (Eslinger 1998).
Previous research demonstrates a reduction in these
skills in populations where social interactions and sub-
jective well-being are compromised (Beck 1967;
Neumann et al. 2011).
Creativity is a multicomponent construct, consisting of
convergent (CT) and divergent thinking (DT) (Guilford
1967). CT is considered a process of generating a single
optimal solution to a particular problem, emphasizing
speed, accuracy, and logic. Conversely, DT is a process
used to generate many new ideas, in a context where more
than one solution is correct. An example of the latter is
a brainstorming session, where generating many
innovative ideas or solutions on a particular issue is the
ultimate goal (Colzato, Szapora, and Hommel 2012).
Although both CT and DT are important in creative
activities, DT may be a more useful estimate of the poten-
tial for creative thought in daily life (Runco and Acar
Emotional, or affective, empathy (EE) refers to the
sharing of emotions, or the ability to feel what another
person is feeling. In contrast, cognitive empathy (CE)
refers to mental perspective taking, or recognizing and
understanding what another person is feeling (Deutsch
and Madle 1975). Previous research suggests
a specificity of the two constructs (Davis 1980), in
that emotional empathy may depend on state variables,
whereas cognitive empathy requires a (trait) ability to
identify another’s emotions (Hurlemann et al. 2010;
Pokorny et al. 2017).
Both creative, flexible thinking and empathy deficits
have been found in stress-related psychopathologies
like depression, anxiety disorders, and post-traumatic
stress disorder (PTSD) (Chamberlain et al. 2006; Cusi
CONTACT Natasha L. Mason Natasha.email@example.com Department of Neuropsychology and Psychopharmacology, Faculty of
Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht 6200 MD, The Netherlands.
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ujpd.
JOURNAL OF PSYCHOACTIVE DRUGS
© 2019 The Author(s). Published with license by Taylor & Francis Group, LLC
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-
nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built
upon in any way.
et al. 2011; Donges et al. 2005; Lee and Orsillo 2014;
Morrison et al. 2016; Nietlisbach et al. 2010; Palm and
Follette 2011; Parlar et al. 2014). Hallmarks of these
disorders are repetitive and rigid patterns of negative
and compulsive thoughts, together with social difficul-
ties and impaired empathic abilities (Aldao, Nolen-
Hoeksema, and Schweizer 2010; Beck 1967; Dos
Santos et al. 2016; Morrison et al. 2016; Nietlisbach
and Maercker 2009; Todd et al. 2015), the latter of
which, most evident in depression, may contribute to
more pronounced symptoms (Cusi et al. 2011; Donges
et al. 2005).
Importantly, previous research has found that these
processes demonstrate plasticity and can be enhanced by
interventions such as therapy programs, hormone admin-
istration, and mindfulness induction, as well as (positive)
changes inmood (Ashby, Isen, and Turken 1999;Baas,De
Dreu, and Nijstad 2008;Davis2009;Dongesetal.2005;
Forgeard and Eichner 2014; Hurlemann et al. 2010;Lee
and Orsillo 2014; Palgi, Klein, and Shamay-Tsoory 2016).
However, these interventions typically target only one of
the two mentioned processes. Thus, by finding treatments
that promote both processes, individual deficits could be
further decreased, potentially enhancing well-being and
quality of life.
Anecdotal evidence and (quasi-)experimental studies
suggest that a single administration of a psychedelic
drug like ayahuasca, LSD, or psilocybin can enhance
creative, flexible thinking and emotional empathy in
the neuro-typical population (Dolder et al. 2016;
Harman et al. 1966; Krippner 1964; Kuypers 2018;
Kuypers et al. 2016; Pokorny et al. 2017; Preller et al.
2015; Sessa 2008; Uthaug et al. 2018). Furthermore,
clinical studies have found that administration of psi-
locybin can induce long-lasting positive psychological
changes, such as symptom remission and enhancement
of well-being, in clinical populations (Carhart-Harris
et al. 2016; Griffiths et al. 2016; Johnson, Garcia-
Romeu, and Griffiths 2017). However, the persistence
of effects on creativity and empathy, and the relation-
ship with subjective well-being, has yet to be assessed.
The present study was designed to assess the sub-acute
effects of psilocybin on creative thinking, empathy, and
subjective well-being. We hypothesized that divergent and
convergent thinking, emotional empathy, and satisfaction
with life would be enhanced sub-acutely with no effect on
cognitive empathy (Pokorny et al. 2017). Furthermore,
based on clinical research demonstrating reductions in
creativity and empathy in individuals with compromised
well-being, we hypothesized that enhancements in such
processes would correlate with increased satisfaction with
life. Finally, as psilocybin has been shown to induce long-
lasting positive increases in well-being, we hypothesized
that participants with previous psilocybin experience
would have a higher baseline satisfaction with life score,
compared to those who are psilocybin-naïve.
Participants were volunteers attending psilocybin retreats
in the Netherlands, organized by the Psychedelic Society
UK. In total, 55 participants (26 female) consented after
goals and methods of the study were explained. Most
participants were from Europe (80%), while the rest
were from North America (7.3%), Africa (3.6%), Central
America (1.8%), and Asia (1.8%), or undisclosed (5.4%).
The highest completed levels of education were graduate
school (41.8%), undergraduate school (41.8%), secondary
school (7.3%), or undisclosed (9.1%). Mean (SD) partici-
pant age was 34.8 (8.9).
About half (52.7%) of the participants had used psilocy-
bin before, and 49.1% had previously used a psychedelic
other than psilocybin (LSD, ayahuasca, or DMT).
Motivations for attending the retreat included “to under-
stand myself”(83.6%), “curiosity”(80%), “to resolve pro-
blems”(49.1%), and “other”(18.2%). For 69.1% of the
participants, this was the first time taking a psychedelic in
a retreat setting.
The study was conducted in accordance with the
Declaration of Helsinki and subsequent amend-
ments concerning research in humans and was
approved by the Ethics Review Committee of
Psychology and Neuroscience. Participation was
voluntary and no incentive to participate was pro-
vided. All volunteers gave their written informed
consent to participate.
Prior to participation in the retreat, personal intakes
were done by the facilitators, which included screening
for (and excluding) individuals with psychiatric disor-
ders or taking psychiatric medications, and medical
factors like high blood pressure.
The setting in which psilocybin was taken was the
same throughout all of the retreats. Participants stayed
in a large house set in nature, hosted by at least two or
more experienced psilocybin facilitators. They arrived
the evening before psilocybin administration, and were
able to get acquainted with each other, the facilitators,
and the schedule of the retreat. The next day, partici-
pants received the psilocybin-containing truffles
around noon, in a tea form. After ingestion,
2N. L. MASON ET AL.
participants were instructed to stay on the premises,
and were able to do what they wanted, as long as they
did not disturb other participants. Facilitators provided
music, tools to draw and/or write, and food. In the
evening, all participants and facilitators came back
together as a group. The next morning, all participants
had breakfast together and had a closing group
Participants ingested the truffles in a tea form, guided
by the facilitators. To do this, the truffles were crushed,
and boiling hot ginger tea was added. After infusing for
a few minutes, the participants drank the tea, and were
subsequently free to add more water and repeat the
process 2–3 times. Afterwards participants could eat
the remaining truffle contents in the cup.
Previous experimental studies have demonstrated
that subjective alterations after psilocybin intake begin
20–40 minutes following administration, peak around
60–90 minutes, and subside by six hours post-intake
(Hasler et al. 2004). However anecdotal reports suggest
that when ingested in tea form, subjective alterations
are felt more quickly, and for a shorter amount of time
Creativity, empathy, and well-being assessments were
taken on three separate occasions: at baseline (the eve-
ning before ingesting psilocybin), the morning after
ingesting psilocybin, and seven days after ingesting
psilocybin. Participants completed pre- and post-
psilocybin assessments at the retreat, with the investi-
gators present. The third assessment was completed
online. The total amount of psilocybin truffles taken
by each participant was recorded, and a sample of the
truffles was taken to determine concentrations of psi-
locybin and its metabolite, psilocin. The German
Central Customs Authority determined the contents
of psilocin and psilocybin after freeze-drying the truf-
fles using a previously described HPLC method
(Laussmann and Meier-Giebing 2010).
Picture concept task
In order to assess creativity, the picture concept task
(PCT) was used (Kuypers et al. 2016). The PCT con-
3 × 3, or 3 × 4. Participants were instructed to find
an association between one of the pictures in each
row. Specifically, they were asked first to provide the
correct solution, as there is only one correct answer.
The number of correct answers served as the depen-
dent measure of convergent thinking. In order to
assess divergent thinking, participants were asked to
provide as many alternative answers as possible. This
is the regular instruction included in measures of
divergent thinking, and it is used to calculate several
parameters—i.e., fluency, originality, and the ratio of
both—which reflect quantity and quality of divergent
thinking. Fluency is defined as the number of alter-
native associations. The second parameter (i.e., ori-
ginality) is calculated by evaluating the originality of
the alternative association relative to those provided
by all other participants in a session. Alternative
answers that were uniquely reported by a single par-
ticipant received an originality score of 2. Answers
that were shared with a single participant were valued
as 1, and answers that were shared by three or more
participants were rated zero. Mean originality (crea-
tivity) scores and ratio originality scores weighed for
fluency (originality/fluency) were used as measures of
divergent thinking. Three parallel versions of the PCT
were used at baseline and the two follow-up measures
after the retreat to avoid learning effects; participants
had 30 seconds per stimulus. Previous studies have
found the PCT to be sensitive to the effects of psy-
chedelics (Kuypers et al. 2016; Prochazkova et al.
Multifaceted empathy test
The multifaceted empathy test (MET) consists of 40
pictures of people in various emotional states, with
50% being positive and 50% negative (Dziobek et al.
2008). To assess cognitive empathy (CE), participants
were asked to select the emotion word, out of four
words, which matched the depicted emotion. To
assess emotional empathy (EE), participants were
asked to rate on a scale from 1 to 9 “how aroused
does this picture make you feel”(implicit EE) and
“how concerned do you feel for this person”(explicit
EE). The number of correctly classified pictures (CE)
and the implicit EE and explicit EE ratings per
valence and averaged across valences were used as
dependent variables. Previous validity and reliability
analysis of the MET have shown to be in the good to
highly satisfactory range (Dziobek et al. 2008), and
previous studies have found it to be sensitive to the
effects of psychedelics (Hysek et al. 2014;Kuypers
et al. 2014,2017; Pokorny et al. 2017;Prelleretal.
JOURNAL OF PSYCHOACTIVE DRUGS 3
Satisfaction with Life Scale
The Satisfaction with Life Scale (SWLS) is a five-item
questionnaire designed to measure global cognitive judg-
ments of satisfaction with one’s life (Diener et al. 1985),
and has been used to measure the life satisfaction compo-
nent of subjective well-being (Diener et al. 1985;Pavot
et al. 1991). Individuals answer each item on a Likert scale
ranging from 1 (strongly disagree) to 7 (strongly agree).
The total score is then obtained by summing the ratings
form each item. Sample items include “In most ways my
life is close to my ideal”and “If I could live my life over,
I would change almost nothing.”The minimum possible
score is 5, and the maximum possible score 35, with
a score of 5–19 defined as dissatisfied to below average
life satisfaction, 20–24 defined as average life satisfaction,
and 29–35 defined as high to very high life satisfaction
(Pavot and Diener 2013). The scale has previously been
shown to be a valid and reliable measure of life satisfac-
tion (Pavot and Diener 2009).
The morning after ingesting psilocybin, participants
were asked to retrospectively rate the intensity of var-
ious aspects of the acute psilocybin experience using 10
visual analog scales (VASs). The VASs were 10 cm
horizontal lines, with a bottom anchor of “not more
than usually”and a top anchor of “much more than
usually.”These items have previously been shown to be
sensitive to the acute effects of psilocybin (Carhart-
Harris et al. 2012).
Statistical analysis was conducted in IBM SPSS
Statistics 24 using a linear repeated measures model
analysis that included Session (three levels: baseline,
morning after psilocybin, and seven days after psilocy-
bin) as a within-subject factor. Due to small sample size
at the seven-day follow-up, a separate linear repeated
measures model analysis was done for each outcome
variable. Similarly, as for the MET, if a main effect of
Session was found on emotional or cognitive empathy,
two further analyses were done, separating valence-
specific (positive or negative emotion) responses.
The covariance structure was chosen according to
best fit and could vary across outcome variables.
Different covariance structures used included com-
pound symmetry heterogenous (CSH) and first lag
autoregressive (AR1) structures. If a main effect of
Session was found, separate contrasts were performed
between baseline and the follow-up sessions with
Bonferroni adjustment for multiple comparisons.
In order to test whether people with previous psilocy-
bin experience differed from psilocybin-naïve partici-
pants on outcome measures, a further mixed-model
analysis was conducted, with Session (three levels: base-
line, morning after psilocybin, and seven days after psilo-
cybin) as a within-subject factor and previous experience
with psilocybin (two levels: yes, no) as a between-subjects
factor, though only for outcome parameters which
showed a significant main effect of Session in the first
analysis. The analysis was performed to determine
whether sub-acute effects of psilocybin differed between
experienced versus naïve psilocybin users.
In order to investigate the association between cog-
nitive (creativity and empathy) and subjective (well-
being) outcome parameters, Pearson’s correlations
were carried out using baseline change scores
(Morning after—baseline; seven days after—baseline).
Psilocybin experience ratings were analyzed sepa-
rately using one-sample ttests comparing the scores
on each VAS after psilocybin versus a zero distribution,
since previous studies have shown that placebo scores
are low, not rising above a 0 in a scale from 0 to 100
(Valle et al. 2016).
In total, 55 participants completed parts of the test
battery at baseline, 50 completed parts of the test bat-
tery the morning after taking psilocybin, and 22 com-
pleted parts of the test battery seven days after taking
psilocybin. Incomplete or missing test batteries were
due to time constraints and/or participant drop-out.
The truffle sample (15 grams; Psilocybe Hollandia)
contained 1.9 mg of psilocybin and 10.5 mg of psilocin.
Participants ingested an average (SD) 34.2 (8.9) grams
of truffles throughout the day. Once ingested, psilocy-
bin is quickly metabolized to psilocin at a calculation
factor of 0.719, resulting in a final (average) psilocin
consumption of 27.1 mg.
Picture concept test
Analysis revealed a significant main effect of Session
= 5.94, p= .01) on the number of correct
associations (see Figure 1(d)). Compared to baseline,
participants were able to identify a higher number of
correct associations seven days after ingesting
4N. L. MASON ET AL.
psilocybin (p= .01; d= .46). There were no significant
effects of psilocybin on convergent thinking the morn-
ing after taking psilocybin.
Analysis revealed a significant main effect of Session on
= 5.27, p= .01) and Originality
= 7.23, p= .002) (see Figure 1(a, b)).
Compared to baseline, participants were able to come
up with more associations (p= .01; d= .47), and had
a higher originality score (p = .001; d= .55), the
morning after taking psilocybin. There was no signifi-
cant effect of session on Ratio (F
= 2.25, p= .12).
Furthermore, there were no significant effects of psilo-
cybin on Fluency, Originality, or Ratio seven days after
Multifaceted empathy test
There was no significant effect of Session on cognitive
= 3.18, p= .06); participants were able
to recognize about 22 emotions on average in the three
sessions (see Figure 2(c, d)).
Analysis revealed a significant main effect of Session
=4.29,p= .02) on average Explicit EE (see
Figure 2(b)). Compared to baseline, participants felt
more concern for people depicting emotions the
morning after ingesting psilocybin (p= .02;
d= .45). When assessing valence-specific responses,
analysis revealed a significant main effect of Session
=5.87,p= .01) on concern ratings of nega-
tive emotions; compared to baseline, individuals’
concern for negative emotions was increased the
morning after taking psilocybin (p= .01; d= .49)
without effects on day 7. There was no significant
effect of Session (F
=2.58,p= .09) on concern
ratings of positive Explicit EE.
Analysis revealed a significant main effect of Session
=10.64,p= .001) on average Implicit EE ratings
(see Figure 2(a)). Compared to baseline, participants felt
more aroused by the emotional content of the stimuli the
morning after ingesting psilocybin (p< .001; d= .71).
When assessing valence-specific responses, analysis
revealed a significant main effect of Session on both
=4.93,p= .02) emotions. Separate contrasts indicated
that, compared to baseline, individuals’arousal to both
positive (p= .001; d= .61) and negative (p= .01; d=.48)
Figure 1. Mean (±SE) outcome variables of divergent and convergent thinking, measured before, the morning after, and seven days
after psilocybin ingestion. Panels A to C depict outcome variables of divergent thinking; (a) fluency; (b) originality; (c) ratio; panel (d)
depicts the outcome variable of convergent thinking (*p < .05).
JOURNAL OF PSYCHOACTIVE DRUGS 5
emotions was higher the morning after ingesting psilocy-
bin. Furthermore, implicit arousal to negative stimuli, but
not positive stimuli, remained increased seven days after
ingesting psilocybin (p=.05;d= .41).
Satisfaction with Life Scale
Analysis revealed a significant main effect of Session
= 17.83, p< .001) on individuals’responses to
the SWLS (see Figure 3(a)). Contrasts indicated that,
compared to baseline, satisfaction with life significantly
increased both the morning after (p< .001; d= .77) and
seven days after (p= .001; d= .50) ingesting psilocybin.
Previous experience with psilocybin
Twenty-nine participants reported previously using
psilocybin, whereas 21 reported being psilocybin
Figure 2. Mean (±SE) outcome variables of implicit emotional empathy (a), explicit emotional empathy (b), and cognitive empathy (c;
total (d)), measured before, the morning after, and seven days after psilocybin ingestion (*p< .05).
Figure 3. Panel A depicts the total group mean (±SE) ratings of satisfaction with life measured before, the morning after, and
seven days after psilocybin ingestion. In panel B, a second analysis was performed to assess differences in satisfaction with life
between those who had previous experience with psilocybin (experienced) and those who had not (naïve). Mean (±SE) ratings per
group are shown (*p< .05).
6N. L. MASON ET AL.
naïve, and five chose not to disclose their previous
drug use history. The latter were thus not included in
this analysis. The analysis revealed a significant main
effect of Session (F
= 16.768, p< .000) and
Psilocybin experience (F
=5.39,p= .025) on
individuals’response to the SWLS (Figure 3(b)).
Contrasts indicated that those who had previous
experience with psilocybin reported a significantly
higher quality of life at baseline compared to those
who were psilocybin naïve (p= .012; d=.39).The
sub-acute effects of psilocybin did not differ between
participants who had used psilocybin vs. those who
had not for any other outcome measures.
Analysis showed medium to strong positive correla-
tions between changes in implicit and explicit EE
towards a positive stimulus and changes in satisfaction
with life. Specifically, as changes in arousal to pictures
of people in positive mood states increased, changes in
satisfaction with life also increased, when comparing
baseline to both the morning after psilocybin intake
(Spearman correlation (r
) = .43, p= .05) and seven days
after intake (r
= .61, p= .02). Furthermore, as changes
in ratings of concern for people in various emotional
states increased between baseline and the morning after
intake, ratings of satisfaction with life increased
between baseline and seven days after intake (r
p= .03). Finally, as changes in ratings of concern for
people in positive mood states increased, changes in
quality of life increased between baseline and seven days
after psilocybin intake (r
= .58, p= .03). No significant
correlations were found between outcome variables of
the PCT and ratings of quality of life, or between
variables of the PCT and the MET.
Mean (SE) ratings on the different VAS items after psilo-
cybin are shown in Figure 4. The one-sample ttests
showed psilocybin-induced significant increases in all
VAS items (t
=14.56–23.73; p≤.000; d=2.05–3.35).
We believe that this study demonstrates the first attempt
to assess the sub-acute influence of psilocybin on creative
thinking, empathy, and their relationship with well-being.
Using a naturalistic approach, significant sub-acute
enhancements of outcome measures of divergent thinking
(DT), convergent thinking (CT), emotional empathy (EE),
and satisfaction with life (LS), after ingestion of psilocybin
Figure 4. Mean (±SE) of visual analogue scale item scores on a 10 cm scale. Scores are retrospective of the psilocybin experience.
JOURNAL OF PSYCHOACTIVE DRUGS 7
at a psychedelic retreat, were demonstrated relative to
baseline. Correlational analyses suggest a positive relation-
ship between sub-acute enhancements in EE and LS.
The findings demonstrate a time- and construct-
related differentiation of effects of psilocybin on crea-
tivity; whereas DT was shown to increase the morning
after ingesting psilocybin relative to baseline, CT was
unaffected. Seven days after ingestion, DT performance
returned to baseline, whereas CT was enhanced.
Previous research has shown that ayahuasca, a South
American plant tea consisting of the similar-acting 5-
agonist N,N-Dimethyltryptamine (DMT), acutely
enhanced DT and impaired CT in individuals partici-
pating in an ayahuasca ceremony (Kuypers et al. 2016).
Furthermore, a similar study demonstrated persisting
sub-acute enhancements of CT one month after parti-
cipation in an ayahuasca ceremony (Uthaug et al.
2018). Taken together, our findings suggest that
whereas psychedelic-induced enhancements of DT out-
last the acute phase, decrements in CT do not. This
discrepancy in acute versus sub-acute effects after
a psychedelic is interesting in light of therapeutic impli-
cations, as both DT and CT are important components
in the therapeutic process. Specifically, it has been
suggested that DT can enhance psychological flexibility
by allowing individuals to generate new, more effective
strategies that facilitate adaptive interpretations and
coping abilities (Forgeard and Elstein 2014).
Consequently, the ability of psilocybin to enhance DT
sub-acutely could help patients to relive events, recall
various associations, and consider their situation from
another perspective (Bouso et al. 2008; Frecska, Bokor,
and Winkelman 2016; Frecska et al. 2012). Longer-term
effects on CT could then be studied in a subsequent
integration session where patients discuss their acute
experiences and decide on a strategy to help them cope
with intensive emotions (Kuypers et al. 2016).
Findings demonstrate a time-, component-, and
valence-differentiation of effects of psilocybin on empa-
thy; whereas explicit and implicit EE were shown to
increase the morning after psilocybin use, CE was unaf-
fected. Furthermore, enhancement in implicit EE to pic-
tures depicting negative emotions persisted until
seven days after use. The sub-acute enhancements in EE
are in line with previous studies assessing acute effects of
psilocybin, as well as other serotonergic psychedelics like
LSD and MDMA, on empathy. Specifically, psilocybin,
LSD, and MDMA have been found to enhance EE on the
MET (Hysek et al. 2014; Kuypers et al. 2014,2017;
Pokorny et al. 2017; Preller et al. 2015;Schmidetal.
2014) without impairing CE. Taken together, these find-
ings suggest that psilocybin (sub)-acutely increases indi-
viduals’ability to feel what other people are feeling,
without affecting individuals’ability to understand what
other people are feeling. Furthermore, psilocybin-induced
increments in arousal to the (negative) emotion of others
outlast induced increments in the ability to feel for others.
Self-rated LS increased after psilocybin ingestion
compared to baseline, both the morning after and
seven days after use. Specifically, at baseline, partici-
pants reported a mean (±SE) score of 22.3 (.96),
a morning-after score of 26.5 (1.03), and seven-day-
after score of 25.6 (1.11). Scores between 20–24 reflect
an “average”LS, defined by general satisfaction, but
with a desire for improvement in major domains (e.g.,
work/school, family) (Pavot and Diener 2013). A score
of 25–29 is considered a “high”score, suggestive of an
enjoyable life and satisfaction in the major domains.
Based on interpretation scores, results suggest that psi-
locybin ingestion increased individuals’LS from “aver-
age”to “high”until at least seven days after use. This
finding is consistent with previous studies showing
acute (Schmid et al. 2014), sub-acute (Barbosa, Giglio,
and Dalgalarrondo 2005;Uthaug et al. 2018), and long-
term (Barbosa et al. 2009; Bouso et al. 2012; Garcia-
Romeu, Griffiths, and Johnson 2015; Griffiths et al.
2011; Grob et al. 2011; Lawn et al. 2017; Osorio et al.
2015; Thomas et al. 2013) positive psychological
changes after psychedelic use. We also assessed whether
there was a relationship between previous experience
with psilocybin and baseline LS scores. In line with the
aforementioned research, it was found that those who
had previously used psilocybin reported higher LS at
baseline compared to those who were psilocybin naïve;
however, this was not related to differences between
groups on performance measures. Altogether, these
results add to the growing body of literature suggesting
beneficial subjective psychological effects of psychedelic
use outlasting acute intoxication.
We hypothesized that changes in empathy and crea-
tivity would correlate with changes in satisfaction with
life. Correlational analysis suggested a positive relation-
ship between changes in LS and changes in implicit EE
(“arousal”). Morning-after change score increases in
arousal in response to positive emotions correlated with
morning-after and seven-day-after change score increases
in subjective ratings of LS. This relationship could be due
to an increase in positive empathy, the phenomenon of
sharing and understanding other’s positive emotions
(Morelli, Lieberman, and Zaki 2015). Specifically, it has
been demonstrated that the ability to share, celebrate, and
enjoy others’positive emotions correlates with increased
prosocial behavior and well-being (Morelli, Lieberman,
and Zaki 2015). Furthermore, it has been hypothesized
that enhanced positive empathy may increase subjective
well-being (Morelli, Lieberman, and Zaki 2015), although
8N. L. MASON ET AL.
directionality has not been established. Our results could
provide limited evidence for directionality, as they
demonstrate that an earlier (morning after) increase in
positive arousal strongly correlates with a later (seven days
after) increase in well-being. However, future research
should more formallyassess a causal relationship between
(positive) empathy and well-being. Alternatively, because
psilocybin acutely enhances response bias towards posi-
tive emotions (Kometer et al. 2012), individuals may feel
more “aroused”when viewing positive emotions because
they are paying more attention to them. The shift of
emotional bias to positive emotions is a proposed
mechanism of antidepressant effects (Kometer et al.
2012), increasing individuals’psychological well-being.
Importantly, previous studies have implicated empathic
deficits in symptom severity of depression (Cusi et al.
2011; Derntl et al. 2012). Therefore, enhancing implicit
emotional empathy could decrease depressive symptom
severity by shifting emotional biases towards positive
Correlational analysis also suggested a relationship
between changes in LS and changes in explicit EE.
Morning-after change score increases in concern for emo-
tional pictures and seven-day-after change score increases
in concern for negative pictures correlated with seven-day-
after change score increases in subjective LS. This is con-
sistent with previous findings of a relationship between
empathic concern and well-being (Gleichgerrcht and
A relationship was not found between changes in
DT or CT and LS. However, the therapeutic implica-
tions of enhanced creativity are still relevant. It may be
that, while not directly increasing subjective well-being,
enhancements in constructs of creativity open up
a“window of opportunity”where therapeutic interven-
tions could prove more effective.
The current study is not without its limitations. The
small sample size restricts the generalizability of the data,
and high drop-out rates result in loss of statistical power
at the seven-day follow-up. Additional factors that restrict
generalizability include the selection bias, as individuals
chose to attend the retreat for various reasons. Due to the
non-random sample, as well as the lack of placebo con-
trol, it could be argued that sub-acute enhancements are
due to uncontrolled factors such as psychological expec-
tations, or the environment in which the drug is taken.
Previous research has shown that both factors, termed set
and setting, play an important role in the outcome of
a psychedelic experience (Lawn et al. 2017;Shewan,
Dalgarno, and Reith 2000). However, previous studies
demonstrating significant enhancement of psychedelics
on creativity, empathy, and positive psychological out-
comes have been found in a wide range of settings,
including clinical (Garcia-Romeu, Griffiths, and Johnson
2015; Griffiths et al. 2016,2011,2006;Osorioetal.2015),
experimental (Hysek et al. 2014; Kuypers et al. 2014,2017;
Pokorny et al. 2017; Preller et al. 2015;Schmidetal.2014),
and naturalistic environments (Barbosa et al. 2009;
Barbosa, Giglio, and Dalgalarrondo 2005; Bouso et al.
2012; Kuypers et al. 2016;Uthaugetal.2018). Taken
together, this is a strong indicator that the present study
effects are directly related to drug intake. That being said,
future placebo-controlled experimental studies could ide-
ally control for the potential influence of non-
pharmacological factors. Finally, future longitudinal clin-
ical research into the therapeutic mechanisms of psilocy-
bin could further assess the role of creativity and empathy
in symptom alleviation in the pathological population.
In conclusion, the present study demonstrates that
psilocybin, taken in a naturalistic setting, promotes
constructs of creativity and empathy, and enhances
subjective well-being. These findings highlight the pos-
sible underlying role of enhanced creativity and empa-
thy in the therapeutic potential of psychedelics.
Importantly, the effects outlast the acute state, poten-
tially opening up a “window of opportunity”where
therapeutic interventions could prove more effective.
These findings add further support to growing evidence
suggesting that psychedelics may hold therapeutic value
for treating stress-related mood disorders.
The authors would like to acknowledge and thank Stefana
Bosse and the Psychedelic Society UK for their collaboration
and permission to collect data at their experience weekends.
They would also like to thank all participants for their time
Natasha L. Mason http://orcid.org/0000-0001-7115-0389
Kim P. C. Kuypers http://orcid.org/0000-0001-7634-3809
Aldao, A., S. Nolen-Hoeksema, and S. Schweizer. 2010.
Emotion-regulation strategies across psychopathology: A
meta-analytic review. Clinical Psychology Review 30
Ashby, F. G., A. M. Isen, and A. U. Turken. 1999.
A neuropsychological theory of positive affect and its influ-
ence on cognition. Psychological Review 106 (3):529–50.
Baas, M., C. K. De Dreu, and B. A. Nijstad. 2008.A
meta-analysis of 25 years of mood-creativity research:
Hedonic tone, activation, or regulatory focus? Psychological
Bulletin 134 (6):779–806. doi:10.1037/a0012815.
JOURNAL OF PSYCHOACTIVE DRUGS 9
Barbosa, P. C., I. M. Cazorla, J. S. Giglio, and R. Strassman.
2009. A six-month prospective evaluation of personality
traits, psychiatric symptoms and quality of life in
ayahuasca-naive subjects. Journal of Psychoactive Drugs
41 (3):205–12. doi:10.1080/02791072.2009.10400530.
Barbosa, P. C., J. S. Giglio, and P. Dalgalarrondo. 2005.
Altered states of consciousness and short-term psycholo-
gical after-effects induced by the first time ritual use of
ayahuasca in an urban context in Brazil. Journal of
Psychoactive Drugs 37 (2):193–201. doi:10.1080/
Beck,A.T.1967.Depression: Clinical, experimental, and theore-
tical aspects. Philadelphia: University of Pennsylvania Press.
Bouso, J. C., R. Doblin, M. Farre, M. A. Alcazar, and
G. Gomez-Jarabo. 2008. MDMA-assisted psychotherapy
using low doses in a small sample of women with chronic
posttraumatic stress disorder. Journal of Psychoactive
Drugs 40 (3):225–36. doi:10.1080/02791072.2008.10400637.
Bouso, J. C., D. González, S. Fondevila, M. Cutchet,
X. Fernández, P. C. R. Barbosa, M. A. Alcázar-Córcoles,
W. S. Araújo, M. J. Barbanoj, and J. M. Fábregas. 2012.
Personality, psychopathology, life attitudes and neuropsy-
chological performance among ritual users of ayahuasca:
A longitudinal study. PloS One 7 (8):e42421. doi:10.1371/
Carhart-Harris, R. L., M. Bolstridge, J. Rucker, C. M. J. Day,
D. Erritzoe, M. Kaelen, M. Bloomfield, J. Rickard,
B. Forbes, A. Feilding, et al. 2016. Psilocybin with psycho-
logical support for treatment-resistant depression: An
open-label feasibility study. The Lancet Psychiatry 3
Carhart-Harris, R. L., D. Erritzoe, T. Williams, J. M. Stone,
L. J. Reed, A. Colasanti, R. J. Tyacke, R. Leech,
A. L. Malizia, K. Murphy, et al. 2012. Neural correlates of
the psychedelic state as determined by fMRI studies with
psilocybin. Proceedings of the National Academy of Sciences
109 (6):2138–43. doi:10.1073/pnas.1119598109.
Carlozzi, A. F., K. S. Bull, G. T. Eells, and J. D. Hurlburt.
1995. Empathy as related to creativity, dogmatism, and
expressiveness. The Journal of Psychology 129 (4):365–73.
Chamberlain, S. R., N. A. Fineberg, A. D. Blackwell,
T. W. Robbins, and B. J. Sahakian. 2006. Motor inhibition
and cognitive flexibility in obsessive-compulsive disorder
and trichotillomania. The American Journal of Psychiatry
163 (7):1282–84. doi:10.1176/appi.ajp.163.7.1282.
Colzato,L.,A.Szapora,andB.Hommel.2012. Meditate to create:
The impact of focused-attention and open-monitoring training
on convergent and divergent thinking. Frontiers in Psychology
3 (116). doi: 10.3389/fpsyg.2012.00116.
Cusi, A. M., G. M. Macqueen, R. R. Spreng, and
M. C. McKinnon. 2011. Altered empathic responding in
major depressive disorder: Relation to symptom severity,
illness burden, and psychosocial outcome. Psychiatry
Research 188 (2):231–36. doi:10.1016/j.psychres.2011.04.013.
Davis, M. A. 2009. Understanding the relationship between
mood and creativity: A meta-analysis. Organizational
Behavior and Human Decision Processes 108 (1):25–38.
Davis, M. H. 1980. A multidimensional approach to indivi-
dual differences in empathy.JSAS Catalog of Selected
Documents in Psychology 10, 85
Decety, J., I. B. A. Bartal, F. Uzefovsky, and A. Knafo-Noam.
2016. Empathy as a driver of prosocial behaviour: Highly
conserved neurobehavioural mechanisms across species.
Philosophical Transactions of the Royal Society B: Biological
Sciences 371 (1686):20150077. doi:10.1098/rstb.2015.0077.
Derntl, B., E. M. Seidel, F. Schneider, and U. Habel. 2012.
How specific are emotional deficits? A comparison of
empathic abilities in schizophrenia, bipolar and depressed
patients. Schizophrenia Research 142 (1):58–64.
Deutsch, F., and R. A. Madle. 1975. Empathy: Historic and
current conceptualizations, measurement, and a cognitive
theoretical perspective. Human Development 18 (4):267–87.
Diener, E., R. A. Emmons, R. J. Larsen, and S. Griffin. 1985.The
satisfaction with life scale. Journal of Personality Assessment
49 (1):71–75. doi:10.1207/s15327752jpa4901_13.
Dolder, P. C., Y. Schmid, F. Müller, S. Borgwardt, and
M. E. Liechti. 2016. LSD acutely impairs fear recognition
and enhances emotional empathy and sociality.
Neuropsychopharmacology 41 (11):2638. doi:10.1038/
Donges, U. S., A. Kersting, U. Dannlowski, J. Lalee-Mentzel,
V. Arolt, and T. Suslow. 2005. Reduced awareness of
others’emotions in unipolar depressed patients. The
Journal of Nervous and Mental Disease 193 (5):331–37.
Dos Santos, R. G., F. L. Osório, J. A. S. Crippa, J. Riba,
A. W. Zuardi, and J. E. C. Hallak. 2016. Antidepressive,
anxiolytic, and antiaddictive effects of ayahuasca, psilocy-
bin and lysergic acid diethylamide (LSD): A systematic
review of clinical trials published in the last 25 years.
Ther Adv Psychopharmacol 6 (3):193–213. doi:10.1177/
Dziobek, I., K. Rogers, S. Fleck, M. Bahnemann,
Dissociation of cognitive and emotional empathy in
adults with Asperger syndrome using the Multifaceted
Empathy Test (MET). Journal of Autism and
Developmental Disorders 38 (3):464–73. doi:10.1007/
Erowid. 2015. Mushroom tea preparation. Erowid.org. Accessed
October 15, 2018. https://erowid.org/plants/mushrooms/
Eslinger, P. J. 1998. Neurological and neuropsychological
bases of empathy. European Neurology 39 (4):193–99.
Forgeard, M. J. C., and K. V. Eichner. 2014.“Creativity as
a target and tool for positive interventions”.InThe Wiley
Blackwell handbook of positive psychological interventions,
edited by A. C. Parks & S. M. Schueller, 137–54. Wiley-
Forgeard, M. J. C., and J. G. Elstein. 2014. Advancing the
clinical science of creativity. Frontiers in Psychology 5:613.
Frecska, E., P. Bokor, and M. Winkelman. 2016. The thera-
peutic potentials of ayahuasca: possible effects against var-
ious diseases of civilization. Frontiers in Pharmacology
Frecska, E., C. E. Móré, A. Vargha, and L. E. Luna. 2012.
Enhancement of creative expression and entoptic phenom-
ena as after-effects of repeated ayahuasca ceremonies.
Journal of Psychoactive Drugs 44 (3):191–99. doi:10.1080/
10 N. L. MASON ET AL.
Garcia-Romeu, A., R. R. Griffiths, and M. W. Johnson. 2015.
Psilocybin-occasioned mystical experiences in the treat-
ment of tobacco addiction. Current Drug Abuse Reviews
Gleichgerrcht, E., and J. Decety. 2013. Empathy in clinical
practice: How individual dispositions, gender, and experi-
ence moderate empathic concern, burnout, and emotional
distress in physicians. PloS One 8 (4):e61526. doi:10.1371/
Griffiths, R. R., M. W. Johnson, M. A. Carducci, A. Umbricht,
W. A. Richards, B. D. Richards, M. P. Cosimano, and
M. A. Klinedinst. 2016.Psilocybinproducessubstantial
and sustained decreases in depression and anxiety in
patients with life-threatening cancer: A randomized
double-blind trial. Journal of Psychopharmacology 30
Griffiths, R. R., M. W. Johnson, W. A. Richards,
B. D. Richards, U. McCann, and R. Jesse. 2011.Psilocybin
occasioned mystical-type experiences: Immediate and per-
sisting dose-related effects. Psychopharmacology 218
Griffiths, R. R., W. A. Richards, U. McCann, and R. Jesse.
2006. Psilocybin can occasion mystical-type experiences
having substantial and sustained personal meaning and
spiritual significance. Psychopharmacology. 187 (3):268–83.
discussion 284-92. doi:10.1007/s00213-006-0457-5.
Grob, C. S., A. L. Danforth, G. S. Chopra, M. Hagerty,
C. R. McKay, A. L. Halberstadt, and G. R. Greer. 2011.
Pilot study of psilocybin treatment for anxiety in patients
with advanced-stage cancer. Archives of General Psychiatry
68 (1):71–78. doi:10.1001/archgenpsychiatry.2010.116.
Guilford, J. P. 1967.The nature of human intelligence.
New York, NY, US: McGraw-Hill.
Harman, W. W., R. H. McKim, R. E. Mogar, J. Fadiman, and
M. J. Stolaroff. 1966. Psychedelic agents in creative
problem-solving: A pilot study. Psychological Reports 19
F. X. Vollenweider. 2004. Acute psychological and physiolo-
gical effects of psilocybin in healthy humans: A double-blind,
placebo-controlled dose–Effect study. Psychopharmacology
172 (2):145–56. doi:10.1007/s00213-003-1640-6.
Hurlemann, R., A. Patin, O. A. Onur, M. X. Cohen,
T. Baumgartner, S. Metzler, I. Dziobek, J. Gallinat,
M. Wagner, W. Maier, et al. 2010. Oxytocin enhances
amygdala-dependent, socially reinforced learning and
emotional empathy in humans. The Journal of
Neuroscience 30 (14):4999–5007. doi:10.1523/jneur-
Hysek, C. M., Y. Schmid, L. D. Simmler, G. Domes,
M. Heinrichs, C. Eisenegger, K. H. Preller, B. B. Quednow,
and M. E. Liechti. 2014. MDMA enhances emotional empa-
thy and prosocial behavior. Social Cognitive and Affective
Neuroscience 9 (11):1645–52. doi:10.1093/scan/nst161.
Johnson, M. W., A. Garcia-Romeu, and R. R. Griffiths. 2017.
Long-term follow-up of psilocybin-facilitated smoking
cessation. The American Journal of Drug and Alcohol
Abuse 43 (1):55–60. doi:10.3109/00952990.2016.1170135.
Kometer, M., A. Schmidt, R. Bachmann, E. Studerus,
E. Seifritz, and F. X. Vollenweider. 2012. Psilocybin biases
facial recognition, goal-directed behavior, and mood state
toward positive relative to negative emotions through dif-
ferent serotonergic subreceptors. Biological Psychiatry 72
Krippner, S. 1964. The hypnotic trance, the psychedelic experi-
ence, and the creative act. American Journal of Clinical
Hypnosis 7(2):140–47. doi:10.1080/00029157.1964.10402408.
Kuypers, K. P. C. 2018. Out of the box: A psychedelic model
to study the creative mind. Medical Hypotheses 115:13–16.
Kuypers, K. P. C., R. de la Torre, M. Farre, S. Yubero-Lahoz,
I. Dziobek, W. van Den Bos, and J. G. Ramaekers. 2014.
No evidence that MDMA-induced enhancement of emo-
tional empathy is related to peripheral oxytocin levels or
5-HT1a receptor activation. PloS One 9 (6):e100719.
Kuypers, K. P. C., P. C. Dolder, J. G. Ramaekers, and
M. E. Liechti. 2017. Multifaceted empathy of healthy volun-
teers after single doses of MDMA: A pooled sample of
placebo-controlled studies. Journal of Psychopharmacology
31 (5):589–98. doi:10.1177/0269881117699617.
Kuypers, K. P. C., J. Riba, M. de la Fuente Revenga, S. Barker,
E. L. Theunissen, and J. G. Ramaekers. 2016. Ayahuasca
enhances creative divergent thinking while decreasing con-
ventional convergent thinking. Psychopharmacology 233
Laussmann, T., and S. Meier-Giebing. 2010.Forensicanalysis
of hallucinogenic mushrooms and khat (Catha edulisForsk)
using cation-exchange liquid chromatography. Forensic
Science International 195 (1):160–64. doi:10.1016/j.
Lawn, W., J. E. Hallak, J. A. Crippa, R. Dos Santos, L. Porffy,
M. J. Barratt, J. A. Ferris, A. R. Winstock, and C. J. A. Morgan.
2017. Well-being, problematic alcohol consumption and
acute subjective drug effects in past-year ayahuasca users:
A large, international, self-selecting online survey. Scientific
Reports 7 (1):15201. doi:10.1038/s41598-017-14700-6.
Lee, J. K., and S. M. Orsillo. 2014. Investigating cognitive
flexibility as a potential mechanism of mindfulness in
Generalized Anxiety Disorder. Journal of Behavior
Therapy and Experimental Psychiatry 45 (1):208–16.
Morelli, S.A., M. D. Lieberman, and J. Zaki. 2015. The emerging
study of positive empathy. Social and Personality Psychology
Compass 9(2):57–68. doi:10.1111/spc3.v9.2.
Morrison, A. S., M. A. Mateen, F. A. Brozovich, J. Zaki,
P. R. Goldin, R. G. Heimberg, and J. J. Gross. 2016.
Empathy for positive and negative emotions in social
anxiety disorder. Behaviour Research and Therapy
M. Wirtz, C. Woopen, A. Haramati, and C. Scheffer. 2011.
Empathy decline and its reasons: A systematic review of studies
with medical students and residents. Academic Medicine 86
Nietlisbach, G., and A. Maercker. 2009. Social cognition and
interpersonal impairments in trauma survivors with PTSD.
Journal of Aggression, Maltreatment & Trauma 18
Nietlisbach, G., A. Maercker, W. Rossler, and H. Haker. 2010.
Are empathic abilities impaired in posttraumatic stress
disorder? Psychological Reports 106 (3):832–44.
JOURNAL OF PSYCHOACTIVE DRUGS 11
Osorio, F. L., R. F. Sanches, L. R. Macedo, R. G. Santos,
effects of a single dose of ayahuasca in patients with recurrent
depression: A preliminary report. Revista brasileira de psi-
quiatria 37 (1):13–20. doi:10.1590/1516-4446-2014-1496.
Palgi, S., E. Klein, and S. G. Shamay-Tsoory. 2016. Oxytocin
improves compassion toward women among patients with
PTSD. Psychoneuroendocrinology 64:143–49. doi:10.1016/j.
Palm, K. M., and V. M. Follette. 2011. The roles of cognitive
flexibility and experiential avoidance in explaining psycho-
logical distress in survivors of interpersonal victimization.
Journal of Psychopathology and Behavioral Assessment 33
Parlar, M., P. Frewen, A. Nazarov, C. Oremus, G. MacQueen,
R. Lanius, and M. C. McKinnon. 2014. Alterations in
empathic responding among women with posttraumatic
stress disorder associated with childhood trauma. Brain
and Behavior 4 (3):381–89. doi:10.1002/brb3.215.
Pavot, W., and E. Diener. 2013. The Satisfaction with Life
Scale (SWL). Measurement instrument database for the
social science. www.midss.ie.
Pavot, W., E. Diener, C. R. Colvin, and E. Sandvik. 1991.
Further validation of the Satisfaction with Life Scale:
Evidence for the cross-method convergence of well-being
measures. Journal of Personality Assessment 57 (1):149–61.
Pavot, W., and E. Diener. 2009.“Review of the satisfaction
with life scale”.InSocial Indicators Research Series: Vol. 39.
Assessing Well-Being: The Collected Works of Ed
Diener (pp. 101–117). New York, NY: Springer Science +
F. X. Vollenweider. 2017.Effectofpsilocybinonempathy
and moral decision-making. International Journal of
Neuropsychopharmacology 20 (9):747–57. doi:10.1093/ijnp/
Preller, K. H., T. Pokorny, R. Krähenmann, I. Dziobek,
P. Stämpfli, and F. X. Vollenweider. 2015. The effect of
5-HT2A/1a agonist treatment on social cognition, empa-
thy, and social decision-making. European Psychiatry
Prochazkova, L., D. P. Lippelt, L. S. Colzato, M. Kuchar,
Z. Sjoerds, and B. Hommel. 2018.Exploring the effect of
microdosing psychedelics on creativity in an open-label
natural setting. Psychopharmacology 235 (12):3401–13.
Runco, M. A., and S. Acar. 2012. Divergent thinking as an
indicator of creative potential. Creativity Research Journal
24 (1):66–75. doi:10.1080/10400419.2012.652929.
Schmid, Y., C. M. Hysek, L. D. Simmler, M. J. Crockett,
B. B. Quednow, and M. E. Liechti. 2014. Differential effects
of MDMA and methylphenidate on social cognition. Journal
of Psychopharmacology 28 (9):847–56. doi:10.1177/
Sessa, B. 2008. Is it time to revisit the role of psychedelic drugs in
enhancing human creativity? Journal of Psychopharmacology
22 (8):821–27. doi:10.1177/0269881108091597.
Shewan, D., P. Dalgarno, and G. Reith. 2000. Perceived
risk and risk reduction among ecstasy users: The role
ofdrug,set,andsetting.International Journal of Drug
Policy 10 (6):431–53. doi:10.1016/S0955-3959(99)
Thomas, G., P. Lucas, N. R. Capler, K. W. Tupper, and
G. Martin. 2013. Ayahuasca-assisted therapy for addiction:
Results from a preliminary observational study in Canada.
Current Drug Abuse Reviews 6 (1):30–42.
T. D. Shanafelt. 2007. How do distress and well-being
relate to medical student empathy? A multicenter study.
Journal of General Internal Medicine 22 (2):177–83.
Todd, A. R., M. Forstmann, P. Burgmer, A. W. Brooks, and
A. D. Galinsky. 2015. Anxious and egocentric: How spe-
cific emotions influence perspective taking. Journal of
Experimental Psychology General 144 (2):374–91.
andJ.G.Ramaekers.2018. Sub-acute and long-term
effects of ayahuasca on affect and cognitive thinking
style and their association with ego dissolution.
Psychopharmacology 235(10): 2979-2989.
Valle, M., A. E. Maqueda, M. Rabella, A. Rodriguez-Pujadas,
R. M. Antonijoan, S. Romero, J. F. Alonso, M. A. Mananas,
S. S. Barker, P. P. Friedlander, et al. 2016. Inhibition of
alpha oscillations through serotonin-2A receptor activa-
tion underlies the visual effects of ayahuasca in humans.
European Neuropsychopharmacology 26 (7):1161–75.
12 N. L. MASON ET AL.