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Cited by 206Psychedelics and Drug StudiesNeurotransmitter Receptor Influence on BehaviorFace Recognition and Perception

Effects of MDMA on sociability and neural response to social threat and social reward

Open access
Bedi, Gillinder, Phan, K. Luan, Angstadt, Mike, de Wit, Harriet·2009·Psychopharmacology
DOI 10.1007/s00213-009-1635-zPMC PMC3328967
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Abstract

Rationale +/-3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") reportedly produces unique subjective effects, including increased sociability, feelings of closeness with others, and reduced interpersonal defensiveness. Despite their apparent importance in recreational and potential psychotherapeutic use of MDMA, the defining characteristics and neurobiological mechanisms of these interpersonal effects are poorly understood.Materials and methods We investigated acute effects of MDMA on self-reported sociability and neuronal activation in response to socially threatening (angry and fearful faces) and socially rewarding (happy faces) stimuli. Assessment of social threat response focused on amygdala activation, whereas assessment of social reward focused on ventral striatum activation. Healthy volunteers (N = 9) reporting past ecstasy use completed three experimental sessions, receiving MDMA (0.75 and 1.5 mg/kg) and placebo (PBO) under double-blind conditions. During peak drug effects, participants underwent functional magnetic resonance imaging while viewing standardized images depicting emotional facial expressions including angry, fearful, happy, and neutral expressions. They also completed standardized self-report measures of sociability.Results MDMA (1.5 mg/kg) increased self-reported sociability compared to MDMA (0.75 mg/kg) and PBO. MDMA (1.5 mg/kg) attenuated left amygdala response to angry facial expressions compared to PBO, but MDMA did not affect amygdala reactivity to fearful expressions. MDMA (0.75 mg/kg) enhanced ventral striatum response to happy expressions relative to PBO.Conclusions These data present the first evidence that MDMA may increase sociability in humans both by diminishing responses to threatening stimuli and enhancing responses to rewarding social signals.

Integrity signals

Registry

Crossref · 10.1007/s00213-009-1635-z

Cites

55 of 55 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

0 of 36 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    MDMA raised peak DEQ ratings of feeling any drug effect.

    “MDMA increased peak DEQ ratings of feeling any drug effect (DEQ Feel Drug; see Table 2).”
    Quote in the paperNot a substantial claim
  • Findingown data

    At 1.5 mg/kg, MDMA reduced primary motor cortex activation during a motor-visual task compared with placebo.

    “In M1, MDMA (1.5mg/kg) also reduced activation compared to PBO ((10, −12, 76), t(8) = 5.82, p < .005, (−12, −28, 74), t(8) = 4.77, p < .005, (66, −6, 14), t(8) = 3.80, p < .005, (16, −36, 70), t(8) = 3.54, p < .005).”
    Quote in the paperNot a substantial claim
  • Findingown data

    The 0.75 mg/kg dose of MDMA raised ventral striatum reactivity to happy faces compared with placebo.

    “MDMA (0.75mg/kg) enhanced ventral striatum response to happy expressions relative to PBO.”
    • Also stated in: § RESULTS · plain
      “T-tests indicated that VS activation to happy versus neutral faces was greater on MDMA (0.75mg/kg) than PBO (t(8) = 6.13, p < .001).”
    • Also stated in: § RESULTS · hedged
      “Analyses of BOLD signal responses extracted from spheres about peak activation for VS happy versus neutral faces also indicated an overall drug effect (F(2,16) = 8.41, p < .005), with VS activation (happy versus neutral faces) greater in both MDMA conditions than PBO (0.75mg/kg: t(8) = 5.51, p < .005; 1.5mg/kg: t(8) = 2.44, p < .05; Figure 4).”
    Quote in the paperSubstantial claim
  • Findingown data

    At 1.5 mg/kg, MDMA reduced primary visual cortex activation during a motor-visual task compared with placebo.

    “In V1, MDMA (1.5mg/kg) decreased activation relative to PBO ((6,−82, 6), t(8) = 3.81, p < .005, (12, −92, 16), t(8) = 3.72, p < .005).”
    Quote in the paperNot a substantial claim
  • Findingown data

    MDMA at 1.5 mg/kg increased self-reported sociability compared with 0.75 mg/kg and placebo.

    “MDMA (1.5mg/kg) increased self-reported sociability compared to MDMA (0.75mg/kg) and PBO.”
    • Also stated in: § RESULTS · plain
      “MDMA significantly increased VAS ratings of Sociability (interaction of drug versus time), with a very large effect size (ήp2 = .28).”
    • Also stated in: § RESULTS · hedged
      “Simple main effects analyses of drug condition at individual time points revealed that MDMA (1.5mg/kg) increased ratings at 135 min relative to MDMA (0.75mg/kg), and marginally increased ratings compared to PBO (see Table 2; Figure 2).”
    Quote in the paperSubstantial claim
  • May combine two claims. 19
  • Classified as probably not a substantial claim. 10

  • May combine two claims.

    Findingown data

    MDMA did not alter accuracy or reaction time on the emotion recognition task.

    “MDMA did not affect accuracy of Emotion Recognition or reaction time, and there was no interactive effect of drug by emotion on accuracy or reaction time.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The 1.5 mg/kg dose also raised ventral striatum response to happy versus neutral faces relative to placebo in extracted BOLD signal, although the whole-brain trend did not survive small volume correction.

    “While not reaching significance, there was also a trend for VS activation to happy versus neutral faces to be greater on MDMA (1.5mg/kg) than PBO (t(8) = 2.72, p < .05); this trend did not survive SVC.”
    • Also stated in: § RESULTS · plain
      “Analyses of BOLD signal responses extracted from spheres about peak activation for VS happy versus neutral faces also indicated an overall drug effect (F(2,16) = 8.41, p < .005), with VS activation (happy versus neutral faces) greater in both MDMA conditions than PBO (0.75mg/kg: t(8) = 5.51, p < .005; 1.5mg/kg: t(8) = 2.44, p < .05; Figure 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    At the lower dose, MDMA enhanced neural response to happy faces without changing subjective sociability ratings.

    “At the lower dose, MDMA enhanced neural response to happy faces without changing subjective sociability ratings.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Subjective effects support the timing of the imaging protocol.

    “Subjective effects support the timing of the imaging protocol.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    The fMRI protocol was designed to coincide with peak drug effects, but blood plasma measurements were not obtained to confirm that imaging coincided with peak plasma MDMA levels.

    “Finally, although the fMRI protocol was designed to coincide with peak drug effects, we did not obtain blood plasma measurements ensuring that imaging data collection coincided with peak plasma MDMA levels.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    THC reduces amygdala response to social threat signals, which may explain its anxiolytic effects.

    “Administration of Δ9-tetrahydrocannabinoid (THC), the main psychoactive constituent of cannabis, reduces amygdala response to social signals of threat, an action that may underlie anxiolytic effects of THC (Phan et al. 2008).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Phan et al. 2008 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The partial randomization protocol and the time between sessions did not affect outcomes.

    “suggesting that the partial randomization protocol and length of time between sessions did not affect outcomes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    MDMA may increase human sociability both by reducing responses to threatening stimuli and by enhancing responses to rewarding social signals.

    “These data present the first evidence that MDMA may increase sociability in humans both by diminishing responses to threatening stimuli and enhancing responses to rewarding social signals.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductown data

    The sample was small, and the findings need replication in a larger sample.

    “The sample was small; these findings require replication in a larger sample.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    MDMA doses were administered in ascending order, which may have influenced outcomes.

    “For safety reasons, MDMA doses were administered in ascending order, which may have influenced outcomes.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Because of the sample size, analyses were limited to two a priori brain regions; larger samples would allow detailed whole-brain examination.

    “Due to the sample size, we restricted analyses to two a priori identified brain region; larger samples would facilitate detailed examination of whole brain.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Positive social stimuli act as natural rewards, and in humans positive social signs such as smiling faces activate reward circuitry.

    “Positive social stimuli act as a natural reward; rodents demonstrate conditioned preferences for places previously paired with a social partner (Douglas et al. 2004; Thiele et al. 2008), and in humans, positive social signs such as smiling faces activate reward circuitry (Tsukiura and Cabeza 2008).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Douglas et al. 2004 source

      Not checked in the free run.

    • cites Thiele et al. 2008 source

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    • cites Tsukiura and Cabeza 2008 source

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  • May combine two claims.

    Interpretationown data

    MDMA changes processing of emotionally salient social information in at least two ways: by lowering threat responses and by raising reward responses.

    “These findings suggest that MDMA alters processing of emotionally salient social information in at least two ways, by reducing responses to threat and by enhancing responses to reward.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The ventral striatum is central to reward processing and responds to rewarding stimuli including drugs of abuse.

    “The ventral striatum (VS) is central to reward processing (Knutson and Cooper 2005), and is activated by a range of rewarding stimuli including drugs of abuse (Gilman et al. 2008).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Knutson and Cooper 2005 source

      Not checked in the free run.

    • cites Gilman et al. 2008 source

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    Premisecitation

    MDMA's acute pharmacodynamic actions include carrier-mediated release of 5-HT from presynaptic vesicles and monoamine oxidase inhibition, causing rapid rises in extracellular 5-HT.

    “MDMA’s acute pharmacodynamic actions include carrier-mediated release of 5-HT from presynaptic vesicles and monoamine oxidase inhibition, resulting in sudden increases in extracellular 5-HT levels (for review, see Green et al. 2003).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Green et al. 2003 source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    A longer interval between sessions may have been needed to ensure no carry-over effects.

    “Thus, it is possible that a longer period between sessions was required to ensure the absence of carry-over effects.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Ricaurte et al. 1988 source

      Not checked in the free run.

    • cites Mechan et al. 2005 source

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  • May combine two claims.

    Study design and conductcitation

    MDMA may affect cerebral blood flow, which could confound BOLD signal, and this possibility cannot be ruled out.

    “Further, MDMA may have actions on cerebral blood flow that affected either global or regionally-specific BOLD signal.”
    • Also stated in: § DISCUSSION · hedged
      “potentially confounding acute effects of MDMA on cerebrovasculature cannot be ruled out.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Gamma et al. 2000 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Selective 5-HT manipulations alter identification and neural processing of emotional faces, as well as affiliative behavior.

    “Selective 5-HT manipulations alter identification (Del-Ben et al., 2008) and neural processing of emotional faces (Harmer et al. 2006), as well as affiliative behavior (Tse and Bond, 2002).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Del-Ben et al., 2008

      Not checked in the free run.

    • cites Harmer et al. 2006 source

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    • cites Tse and Bond, 2002 source

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  • Classified as probably not a substantial claim.

    Premisecitation

    5-HT neurotransmission is implicated in social processing and behavior.

    “A substantial body of literature implicates 5-HT neurotransmission in social processing and behavior (e.g. Del-Ben et al. 2008; Young and Leyton, 2002).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Del-Ben et al. 2008

      Not checked in the free run.

    • cites Young and Leyton, 2002 source

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  • May combine two claims.

    Premisecitation

    These rodent behavioral changes involve oxytocin release, and oxytocin receptor antagonism reduces MDMA's prosocial effects.

    “These behavioral changes involve release of oxytocin (OT), a neuropeptide implicated in attachment and pair bonding, with OT receptor antagonism attenuating MDMA’s prosocial effects in rodents (Thompson et al. 2007).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Thompson et al. 2007 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Study design and conductreasoning

    The present findings should be regarded as preliminary.

    “The present findings should be regarded as preliminary; there are a number of limitations remaining to be addressed.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationcitation

    This variability may have affected results, as heavy ecstasy use may cause long-term alterations to serotonergic neurotransmission.

    “This may have affected results, as it is possible that heavy ecstasy use causes long-term alterations to serotonergic neurotransmission (McCann et al. 2000; see also Bedi et al., 2008 for discussion of methodological issues).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites McCann et al. 2000 source

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    • cites Bedi et al., 2008 source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Because serotonin is involved in vasoconstriction, prior or recent MDMA exposure might have affected BOLD responses.

    “Moreover, due to involvement of serotonin in vasoconstriction (Cohen et al. 1996), it is possible that prior or recent MDMA exposure might have affected BOLD responses.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Cohen et al. 1996 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Brain responses to social stimuli may be more sensitive indicators of prosocial effects than subjective ratings, and higher doses may be needed for people to report feeling more sociable.

    “It is possible that brain responses to social stimuli are more sensitive indicators of prosocial effects, and that higher doses may be needed for individuals to report feeling more sociable.”
    Quote in the paperSubstantial claim
24 of 24

  • The paper relies on this without support.

    The nature and neural basis of MDMA's interpersonal effects remain poorly characterized.

    “Despite their apparent importance in recreational and potential psychotherapeutic use of MDMA, the defining characteristics and neurobiological mechanisms of these interpersonal effects are poorly understood.”
    “Despite generating widespread interest, the purported empathogenic effects of MDMA are poorly understood.”

  • The paper relies on this without support.

    How drugs of abuse generally affect processing of salient material is not well understood.

    “effects of drugs of abuse in general on processing of salient material are poorly understood.”

  • The paper relies on this without support.

    Apart from MDMA, no drug has been reported to raise subjective sociability while both lowering threat responses and raising reward responses.

    “To our knowledge, no other drug has been found to increase subjective sociability while both attenuating responses to social threat and increasing social reward responding.”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • MDMA appears to modulate fear responses by reducing activity in the amygdala, decreasing reactions to socially threatening stimuli while enhancing responses to socially rewarding signals.

    “MDMA also appears to modulate fear responses by reducing activity in the amygdala, decreasing reactions to socially threatening stimuli while enhancing responses to socially rewarding signals - an effect that may influence emotional memory processing (89).”

    From Psychoanalytically informed MDMA-assisted therapy for pathological narcissism: a novel theoretical approach (2025) · cites this paper as [89]

    The Results (page not supplied) report reduced amygdala activation to angry faces and increased ventral-striatum activation to happy faces, supporting the social-threat and reward components. The claim is broader than the finding: MDMA did not reduce amygdala reactivity to fearful faces, and the study did not establish a general reduction in fear responses. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • MDMA improves psychological flexibility, reduces fear of negative evaluation, and enhances self-reflection.

    “MDMA has been shown to improve psychological flexibility, reduce fear of negative evaluation, and enhance self-reflection (89, 134–136).”

    From Psychoanalytically informed MDMA-assisted therapy for pathological narcissism: a novel theoretical approach (2025) · cites this paper as [89]

    The Discussion reports increased self-rated sociability and reduced neural responses to threatening social stimuli after MDMA, which lends limited support to the claim about reduced social fear. It does not establish reduced fear of negative evaluation as a reported experience, and neither psychological flexibility nor self-reflection was measured. The Introduction describes psychological openness as an argument made by advocates, not a demonstrated finding of this study. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • MDMA's ability to reduce perception of social threat may be particularly beneficial for patients with PN.

    “For patients with PN, who are prone to interpersonal defensiveness and hypersensitivity to social rejection, MDMA’s ability to reduce perception of social threat may be particularly beneficial (89).”

    From Psychoanalytically informed MDMA-assisted therapy for pathological narcissism: a novel theoretical approach (2025) · cites this paper as [89]

    The Results and Discussion (page unavailable) report that MDMA reduced amygdala responses to angry faces and dampened neural responses to social threat. They do not establish reduced conscious perception of threat: the Results report no change in emotion-recognition accuracy. The study involved healthy volunteers, not patients with PN, so a particular benefit for those patients remains an inference. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • The authors' earlier imaging work found MDMA changed brain responses to social cues, yet it left behavioral accuracy for recognizing facial emotions unchanged.

    “Using fMRI, we recently reported effects of MDMA on neural processing of social material [12], but in that study the drug did not alter the behavioral response to the stimuli (i.e. accuracy of identification of emotions from pictures of facial effect).”

    From Is Ecstasy an “Empathogen”? Effects of +/- 3,4-Methylenedioxymethamphetamine on Prosocial Feelings and Identification of Emotional States in Others (2010) · cites this paper as [12]

  • Reduced recognition of negative emotions, especially threat cues like fear, could promote approaching others socially.

    “A decreased ability to identify negative emotions, particularly threat-related signals such as fear, may facilitate social approach behavior [12, 35].”

    From Is Ecstasy an “Empathogen”? Effects of +/- 3,4-Methylenedioxymethamphetamine on Prosocial Feelings and Identification of Emotional States in Others (2010) · cites this paper as [12]

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • Not confirmedt(8) = 3.81reported p < .005 · recomputed p = .005

    “t(8) = 3.81, p < .005”

  • Not confirmedt(8) = 3.72reported p < .005 · recomputed p = .006

    “t(8) = 3.72, p < .005”

  • Not confirmedt(8) = 3.8reported p < .005 · recomputed p = .005

    “t(8) = 3.80, p < .005”

  • Not confirmedt(8) = 3.54reported p < .005 · recomputed p = .008

    “t(8) = 3.54, p < .005”

  • ConsistentF(2, 16) = 9.64reported p < .005 · recomputed p = .002

    “F(2,16) = 9.64, p < .005”

  • Consistentt(8) = 4.41reported p < .005 · recomputed p = .002

    “t(8) = 4.41, p < .005”

  • ConsistentF(2, 16) = 7.24reported p < .01 · recomputed p = .006

    “F(2,16) = 7.24, p < .01”

  • Consistentt(8) = 3.34reported p < .05 · recomputed p = .010

    “t(8) = 3.34, p < .05”

  • Consistentt(8) = 2.44reported p < .05 · recomputed p = .041

    “t(8) = 2.44, p < .05”

  • ConsistentF(2, 16) = 9.75reported p < .005 · recomputed p = .002

    “F(2,16) = 9.75, p < .005”

  • Consistentt(8) = 6.13reported p < .001 · recomputed p < .001

    “t(8) = 6.13, p < .001”

  • Consistentt(8) = 2.72reported p < .05 · recomputed p = .026

    “t(8) = 2.72, p < .05”

  • ConsistentF(2, 16) = 8.41reported p < .005 · recomputed p = .003

    “F(2,16) = 8.41, p < .005”

  • Consistentt(8) = 5.51reported p < .005 · recomputed p < .001

    “t(8) = 5.51, p < .005”

  • Consistentt(8) = 5.82reported p < .005 · recomputed p < .001

    “t(8) = 5.82, p < .005”

  • Consistentt(8) = 4.77reported p < .005 · recomputed p = .001

    “t(8) = 4.77, p < .005”

16 of 16

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Abstract and results disagree on which MDMA dose changes sociability

    Minor

    The Abstract says the higher dose increased self-reported sociability compared to both the lower dose and placebo. Later results state that MDMA significantly increased VAS Sociability with a dose effect, but the specific simple main effect reported is that the higher dose increased ratings relative to the lower dose and only marginally relative to placebo, which is not the same claim as a confirmed increase over placebo.

  • Abstract overstates the sociability comparison with placebo

    Minor

    The abstract presents the higher dose as increasing sociability relative to placebo, but the Results describe that comparison as only marginal. The reported increase relative to the lower dose does not resolve this discrepancy.

2 of 2

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Walter B, Blecker C, Kirsch P, Sammer G, Schlienle A, Stark R, et al (2003). MARINA: An easy to use tool for the creation of MAsks for Region of INterest Analyses. Paper presented at Ninth International Conference on Functional Mapping of the Human Brain New York, NY, June

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Related

Authors
Bedi, G., Phan, K. L., Angstadt, M., & de Wit, H.
Affiliations
  • University of Chicago (US)
  • University of Michigan (US)
ORCID
Venue
Psychopharmacology
Publisher
Springer Science and Business Media LLC
Published
2009-08-13
Volume
207
Issue
1
Pages
73-83
ISSN
  • 0033-3158 (ISSN-L)
  • 1432-2072
DOI
10.1007/s00213-009-1635-z
PMC
PMC3328967
OpenAlex
W2034818162
Cited by
206
References
55
Citations by year
2026: 10 · 2025: 15 · 2024: 18 · 2023: 17 · 2022: 8 · 2021: 13 · 2020: 9 · 2019: 7 · 2018: 23 · 2017: 12 · 2016: 15 · 2015: 15 · 2014: 13 · 2013: 15 · 2012: 4
FWCI
5.65
Type
journal article
Language
en
Open access
Licence
www.springer.com/tdm (tdm)
Locations
  • Psychopharmacology (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
National Institute on Drug Abuse (DA 02812, R01DA002812)
Topics
  • Social Sciences › Psychology › Clinical Psychology › Psychedelics and Drug Studies
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neurotransmitter Receptor Influence on Behavior
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Face Recognition and Perception
Keywords
MDMA, ecstasy, sociability, social danger, social reward, amygdala, ventral striatum, emotional facial expressions, acute drug effects
MeSH terms
Adolescent, Adult, Analysis of Variance, Blood Pressure, Brain, Brain Mapping, Dose-Response Relationship, Drug, Double-Blind Method, Emotions, Hallucinogens, Heart Rate, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Oxygen, Pain Measurement, Pattern Recognition, Visual, Photic Stimulation, Reward, Social Behavior, N-Methyl-3,4-methylenedioxyamphetamine, Young Adult

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