About

Margaret Johnson is an Associate Professor in the Department of Biophysics at Johns Hopkins University, which she joined in 2013. She holds a B.S. in Applied Math from Columbia University and a Ph.D. in Bioengineering from UC Berkeley. Her postdoctoral work was completed in the Lab of Chemical Physics at the NIH. Her multidisciplinary research group studies dynamical systems in biology, focusing on how macromolecular self-assembly is controlled to occur at the right place and time within cells. Her research addresses processes such as endocytosis, viral exit, and transcriptional regulation, developing and applying theory, modeling, and simulations in collaboration with experimentalists. Dr. Johnson's work aims to understand the principles and design of self-assembly and its biological functions, utilizing modeling techniques from physics, chemistry, and engineering, including molecular models, reaction-diffusion models, and continuum models. Her research has contributed to understanding how localization to membranes can enhance assembly processes and how the stoichiometry of protein networks influences cellular functions. She has received several awards, including an NIH Pathway to Independence Award, an NSF CAREER Award, and an NIH MIRA Award.

Research topics

• Internal medicine
• Psychiatry
• Medicine
• Psychology
• Clinical psychology

Selected publications

• Shame, Guilt and Psychedelic Experience: Results from a Prospective, Longitudinal Survey of Real-World Psilocybin Use

  Journal of Psychoactive Drugs · 2025-02-07 · 9 citations

  article

  The classic psychedelic psilocybin has attracted special interest across clinical and non-clinical settings as a potential tool for mental health. Despite increasing attention to challenging psychedelic experiences, few studies have explored the relevance of shame-related processes with psychedelic use. This prospective, longitudinal study involved sequential, automated, web-based surveys that collected data from 679 adults planning to use psilocybin in naturalistic settings at timepoints before and after psilocybin use. State and trait shame and feelings of guilt were collected using validated measures and assessed alongside other measurements of psychological health. Acute feelings of shame or guilt during psilocybin experiences were commonly reported (68.2% of users) and difficult to predict. Ratings of participant ability to constructively work through these feelings predicted wellbeing 2-4 weeks after psilocybin use. Psilocybin on average produced a small but significant decrease in trait shame that was maintained 2-3 months after use (Cohen's dz = 0.37). Trait shame increased in a notable minority of participants (29.8%). The activation of self-conscious emotions with psychedelics deserves further attention as a challenging experience subcategory that may be relevant to psychological outcomes. Such experiences could pose a unique and context-dependent learning condition for both therapeutic and detrimental forms of shame-related memory reconsolidation.

  PublisherDOI

• Adverse reactions among psychedelic users: Norwegian validation of the Challenging Experience Questionnaire

  Journal of Psychiatric Research · 2025-05-26 · 3 citations

  articleOpen accessSenior author

  Psychedelic drugs, known for their potent psychoactive effects, have gained attention for their potential therapeutic benefits in treating mental disorders.However, distressing experiences induced by psychedelics can lead to adverse long-term effects. To better assess these experiences, we aimed to provide a Norwegian translation and psychometric validation of the Challenging Experience Questionnaire (CEQ), a key tool for evaluating adverse psychedelic experiences. Our study employed an anonymous online survey targeting Norwegian recreational psychedelic users, focusing on their most memorable psychedelic encounter. A sample of 729 participants, predominantly male (73%) and aged between 26-35 years (41%), with 90% having used LSD or psilocybin, was analyzed. Half of the participants had completed a university degree, and 48% reported a diagnosed mental disorder. The CEQ underwent a rigorous seven-stage translation process and was included in the survey to validate the original 7-factor structure. Our findings revealed excellent internal consistency (alpha = 0.94) and robust overall model fit (χ 2 [278] = 1451.80, RMSEA = .076, SRMR = .051, CFI = .913) for the 7-factor model, with evidence of factorial invariance across gender and psychiatric status. Further, the relationship between reported difficulty and CEQ factors such as fear, grief, insanity, and death underscored its convergent validity. In conclusion, our study confirms the 7-factor structure of the CEQ while demonstrating its reliability and validity. This provides Norwegian researchers with a culturally adapted, psychometrically valid tool for assessing complex adverse reactions to psychedelic use. • 729 participant responses analyzed, matching other studies' demographics. • Norwegian CEQ internal consistency was high (α = 0.94) • Confirmatory factor analysis confirms 7-factor model fit • Factor structure invariant across gender/psychiatric status groups. • Significant relationship between CEQ factors and later well-being and difficulty.

  PublisherDOI

• On the varieties of conscious experiences: Altered Beliefs Under Psychedelics (ALBUS)

  Neuroscience of Consciousness · 2025-01-01 · 12 citations

  articleOpen accessSenior author

  How is it that psychedelics so profoundly impact brain and mind? According to the model of "Relaxed Beliefs Under Psychedelics" (REBUS), 5-HT2a agonism is thought to help relax prior expectations, thus making room for new perspectives and patterns. Here, we introduce an alternative (but largely compatible) perspective, proposing that REBUS effects may primarily correspond to a particular (but potentially pivotal) regime of very high levels of 5-HT2a receptor agonism. Depending on both a variety of contextual factors and the specific neural systems being considered, we suggest opposite effects may also occur in which synchronous neural activity becomes more powerful, with accompanying "Strengthened Beliefs Under Psychedelics" (SEBUS) effects. Such SEBUS effects are consistent with the enhanced meaning-making observed in psychedelic therapy (e.g. psychological insight and the noetic quality of mystical experiences), with the imposition of prior expectations on perception (e.g. hallucinations and pareidolia), and with the delusional thinking that sometimes occurs during psychedelic experiences (e.g. apophenia, paranoia, engendering of inaccurate interpretations of events, and potentially false memories). With "Altered Beliefs Under Psychedelics" (ALBUS), we propose that the manifestation of SEBUS vs. REBUS effects may vary across the dose-response curve of 5-HT2a signaling. While we explore a diverse range of sometimes complex models, our basic idea is fundamentally simple: psychedelic experiences can be understood as kinds of waking dream states of varying degrees of lucidity, with similar underlying mechanisms. We further demonstrate the utility of ALBUS by providing neurophenomenological models of psychedelics focusing on mechanisms of conscious perceptual synthesis, dreaming, and episodic memory and mental simulation.

  PublisherDOI

• Psychedelics and substance use disorder treatment

  International review of neurobiology · 2025-01-01 · 5 citations

  reviewSenior authorCorresponding
  PublisherDOI

• Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Subcutaneous RE104

  Journal of Clinical Psychopharmacology · 2025-07-21

  articleOpen access

  BACKGROUND: This study is the first to formally evaluate in humans the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of RE104, a prodrug of the synthetic psychedelic known as 4-hydroxy-N,N-diisopropyltryptamine or 4-OH-DiPT. METHODS: This double-blind, randomized, placebo-controlled, phase 1 study of single subcutaneous (SC) doses of RE104 (5 to 40 mg) included 6 cohorts and a total of 48 healthy adult participants with prior experiences with hallucinogenic or psychedelic compounds. RESULTS: SC doses of RE104 were generally safe up to 40 mg with no serious adverse events (AEs) or deaths. Most AEs occurred acutely under supervision and were mild to moderate. The Columbia-Suicide Severity Rating Scale score did not increase during the study, and the Assessment of Alertness and Sedation Scale was largely normal at all timepoints regardless of dose. RE104 exposure, based on Cmax, AUC 0-t , and AUC 0-inf , increased with dose from 5 to 40 mg RE104. 4-OH-DiPT appeared rapidly in plasma (median T max ranged from 1.0 to 1.25 hours across dose groups). Mean plasma 4-OH-DiPT t ½ ranged from 2.72 hours to 4.12 hours. PKs appeared linear at the doses examined. Plasma levels of 4-OH-DiPT correlated with the Drug Effect Questionnaire and Mystical Experience Questionnaire (MEQ). Dose-related increases were observed in frequency of the MEQ 30 "complete mystical experience" responders. CONCLUSIONS: Single SC doses of RE104 resulted in a psychoactive experience and a favorable safety profile similar to psilocybin but with a shorter duration of psychoactive effect (3 to 4 hours). Results suggest a potential for therapeutic effect, warranting further study.

  PublisherDOI

• Time estimation variability in delay discounting: Model comparison and considerations

  Behavioural Processes · 2025-10-09

  articleOpen access
  PublisherOA PDFDOI

• Attitudes and Perceptions of Portuguese Psychiatrists and Psychologists on the Clinical Use of Ketamine

  Acta Médica Portuguesa · 2025-05-02 · 1 citations

  articleOpen access

  INTRODUCTION: Ketamine has garnered attention for its rapid efficacy in alleviating depressive symptoms in treatment-resistant depression, offering a novel mechanism as a non-monoaminergic agent. Despite its potential, limited research has explored mental health professionals' perspectives on its use. This study assesses the attitudes, knowledge, and concerns of Portuguese psychiatrists and psychologists regarding the clinical application of ketamine in treatment-resistant depression. METHODS: A cross-sectional survey study was conducted from June 2022 to January 2024 among Portuguese psychiatrists and psychologists. The anonymous online questionnaire assessed perceptions of ketamine's therapeutic utility, risks, and knowledge sources. Statistical analyses examined subgroup differences by age, sex, profession, and prior psychedelic use. RESULTS: Among 156 participants (mean age = 37.2; 68.6% female), 53.8% were psychologists, and 46.2% were psychiatrists or trainees in Psychiatry. Only 35.9% reported substantial knowledge of ketamine's therapeutic potential, while 59% were open to integrating it clinically. The majority expressed interest in training, though 73% raised concerns about inadequate professional training. Significant differences emerged, with psychiatrists reporting higher knowledge levels and openness to ketamine compared to psychologists, while younger professionals showed greater interest in training and usage. CONCLUSION: There was a favorable attitude toward ketamine use among Portuguese psychiatrists and psychologists, yet substantial educational gaps remain. Customized training addressing age, sex, and professional background is essential for safe and effective clinical integration of ketamine in treatment-resistant depression. Further studies should focus on longitudinal outcomes of ketamine treatment under standardized protocols to ensure efficacy and safety in clinical practice.

  PublisherOA PDFDOI

• Effects of Psilocybin on Religious and Spiritual Attitudes and Behaviors in Clergy from Various Major World Religions

  Psychedelic Medicine · 2025-05-16 · 14 citations

  articleOpen access

  Background: Although historical writings, anthropological accounts, and experimental studies document associations between psilocybin use and religion, no prospective experimental study has investigated how the effects of psilocybin are experienced and interpreted by religious clergy. This exploratory study evaluated the overall safety and the acute and enduring effects of psilocybin in clergy. Methods: = 16) at 6 months after screening using self-report measures. The effects of psilocybin were also assessed on session days and 4 and 16 months after the second psilocybin session in the 24 participants who completed both sessions. Results: The primary outcome assessment at 6 months after screening showed that, compared with the delayed control group, participants who had received psilocybin reported significantly greater positive changes in their religious practices, attitudes about their religion, and effectiveness as a religious leader, as well as in their non-religious attitudes, moods, and behavior. Follow-up assessments showed that positive changes in religious and non-religious attitudes and behavior were sustained through 16 months after the second psilocybin session. At that time, participants rated at least one of their psilocybin experiences to be among the top five most spiritually significant (96%), profoundly sacred (92%), psychologically insightful (83%), and psychologically meaningful (79%) of their lives. Furthermore, 42% rated one of their experiences to be the single most profound of their lifetime. At 16-months follow-up, most (79%) strongly endorsed that the experiences had positive effects on their religious practices (e.g., prayer or meditation) and their daily sense of the sacred, and most (71%) reported positive changes in their appreciation of religious traditions other than their own. Although no serious adverse events were reported, 46% rated a psilocybin experience as among the top five most psychologically challenging of their lives. Conclusions: In this population of clergy, psilocybin administration was safe and increased multiple domains of overall psychological well-being including positive changes in religious attitudes and behavior as well as their vocation as a religious leader. The study was limited by a waitlist control design, homogenous sample, and the use of some unvalidated outcome measures. Further research with more rigorous control conditions and diverse samples is needed.

  PublisherOA PDFDOI

• A Field-Wide Review and Analysis of Study Materials Used in Psilocybin Trials: Assessment of Two Decades of Research

  Psychedelic Medicine · 2025-01-20 · 7 citations

  reviewOpen access

  Introduction: Serotonergic psychedelics, serotonin 2A receptor agonists such as psilocybin that can result in substantially altered states of consciousness, are used in recreational and research settings. The safety of psychedelic experiences in research settings is supported by controlled physical environments, presence of clinical and medical staff to address emergent issues, screening for personal and family history of potential contraindications, and psychoeducational preparation with psychological support. Research settings typically provide psychoeducation to participants verbally and in writing (e.g., informed consent), and such documents and conversations can provide safety-related information-but may also introduce a wide range of expectancies. Such expectancies might involve the specific character of the acute subjective effects of psychedelics, possible side effects, and anticipated outcomes. Methods: To better understand the content of this psychoeducation, we gathered study materials from many psilocybin studies conducted in the past two decades in healthy and therapeutic populations. We conducted a reflexive thematic analysis to better understand these documents. Results: While these documents varied substantially between studies, we identified themes intended to lower levels of risk and optimize therapeutic effects from psychedelic treatments. The most frequently coded themes related to (1) biological and physical safety, (2) psychological safety and well-being, (3) aspects of setting, and (4) potential for expectancies. Prioritizing biological and psychological safety was evident in the materials from all sites. Furthermore, we identify potential contributors to expectancy unrelated to safety and suggest that these extrapharmacological elements be studied systematically in future research. Conclusions: Ideally, future research should strive to maximize safety while attempting to minimize extraneous expectancies.

  PublisherOA PDFDOI

• Hypothetical Purchase Task Metrics Predict Responding on an Incentivized Purchase Task for Full and Reduced Nicotine Cigarettes

  Nicotine & Tobacco Research · 2025-06-24 · 1 citations

  article

  INTRODUCTION: The purchase task procedure offers a rapid data collection method for evaluating drug value in contexts for which drug self-administration is practically or ethically limited. This study addresses a methodological concern with purchase task use-the correspondence between hypothetical and real commodity valuation-by testing the say-do and hypothetical-incentivized correspondence of the task for tobacco demand across varied tobacco products. AIMS AND METHODS: Participants (N = 24; 50% female) completed study sessions characterized by changing cigarette product characteristics. During each session, participants sampled a cigarette varying in blinded nicotine content and nicotine expectancy and completed hypothetical and incentivized purchase tasks for that product. The incentivized task prompted participants to report the number of session cigarettes they would purchase for a within-session self-administration period while the hypothetical task evaluated simulated purchases of cigarette packs for a typical smoking week. Measures of correspondence were evaluated across purchase task metrics. RESULTS: Across conditions, purchasing and self-administration in the incentivized purchase task and self-administration period showed a strong positive correlation (r = .70, p < .001). Average correlations for each metric between task types ranged from r = .43 [Omax] to r = .55 [breakpoint]. Linear mixed-effects modeling revealed statistically significant predictive relations between hypothetical and incentivized task metrics for Q0 (p < .001), ⍺ (p < .001), intensity (p < .001), Omax (p = .04), Pmax (p = .01), and breakpoint (p < .001). CONCLUSIONS: Data uphold the correspondence between hypothetical and incentivized task responding in the context of familiar and novel cigarette products. Broadly, data provide continued support for the purchase task method as a reliable and ecologically valid method of assessing reinforcer valuation. IMPLICATIONS: A limited body of research precludes conclusions regarding the say-do correspondence of simulated purchase tasks. This study examines correspondence across a hypothetical task prompting participants to report tobacco valuation in units of packs and an incentivized task prompting participants to report single cigarette consumption for use during a within-session self-administration period. The task correspondence observed in this study supports the continued use of behavioral economic simulated purchase tasks for application in difficult-to-study contexts.

  PublisherDOI

Recent grants

• NIH Grant R21DA026967

  NIH · $451k · 2012

• Development of a Prospective Memory Intervention to Reduce Drug Use and HIV Risk

  NIH · $2.0M · 2013–2019

• NIH Grant R21DA036675

  NIH · $443k · 2018

• NIH Grant R01DA032363

  NIH · $959k · 2016

• NIH Grant R21DA029823

  NIH · $451k · 2013

Frequent coauthors

• Roland R. Griffiths

  Johns Hopkins University

  360 shared

• Peter H. Addy

  VA Connecticut Healthcare System

  162 shared

• Maite Garrido

  Institut d'Investigacions Biomèdiques de Barcelona

  162 shared

• M. J. González

  162 shared

• Judit Claramunt

  Louisiana State University

  162 shared

• Jimena Coimbra

  Hospital de Sant Pau

  162 shared

• Jordi Riba

  Universitat Autònoma de Barcelona

  162 shared

• Marta Valle

  Universitat Autònoma de Barcelona

  162 shared

Labs

• Johnson GroupPI

Awards & honors

• NIH Pathway to Independence Award
• NSF CAREER Award
• NIH MIRA Award