Matthew W Johnson

Johns Hopkins Medicine | JHUSOM · Department of Psychiatry and Behavioral Sciences

Studies suggest that reduced-nicotine cigarettes decrease nicotine intake and dependence. However, questions remain about reduced-nicotine cigarette abuse liability, whether reduced-nicotine cigarette exposure lowers reduced- and full-nicotine cigarette use, and whether reduced-nicotine cigarettes substitute for full-nicotine cigarettes. This rando...

Literature concerning operant behavioral economics shows a strong preference for the coefficient of determination ( R ² ) metric to (a) describe how well an applied model accounts for variance and (b) depict the quality of collected data. Yet R ² is incompatible with nonlinear modeling. In this report, we provide an updated discussion of the concer...

Current FDA plans include proposed nicotine reduction mandates by the end of 2023. Most research on reduced nicotine cigarettes has been dose-blinded, while a mandate would be known to the public. Few laboratory studies have examined specifically how low nicotine content labeling impacts behavioral response. The purpose of this within-subject, bala...

Substance use disorders (SUDs) have an enormous impact on public health. With classic psychedelic-assisted therapies showing initial promise in treating multiple SUDs, it is possible that these treatments will become legally available options for patients with SUDs in the future. This article highlights how classic psychedelic-assisted therapies mi...

Introduction: The classic psychedelic psilocybin has attracted special interest across clinical and non-clinical settings as a potential tool for mental health. However, despite increasing attention to challenging psychedelic experiences, few studies have explored the relevance of emotionally painful, shame-related processes with psychedelic use. M...

Introduction The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain lim...

Introduction: The Tobacco Control Act gives the US FDA authority to establish a reduced-nicotine content standard in combusted cigarettes. This future potential regulation may pose a significant public health benefit; however, black markets may arise to meet demand for normal-nicotine content cigarettes among smokers unwilling to transition to or...

Objective: To systematically review control conditions of all available randomized psychedelic trials. Data Sources: We searched PubMed, PsycINFO, and EMBASE for randomized trials of psychedelics in humans from 1940 through May 2020 with no language restrictions. PRISMA guidelines were followed. (PROSPERO registration number: PROSPERO-CRD4202020534...

Rationale: Behavioral economic drug purchase tasks quantify the reinforcing value of a drug (i.e., demand). Although widely used to assess demand, drug expectancies are rarely accounted for and may introduce variability across participants given diverse drug experiences. Objectives: Three experiments validated and extended previous hypothetical...

While the literature on psychedelic medicine emphasizes the im- portance of set and setting alongside the quality of subjective drug effects for therapeutic efficacy, few scholars have explored the therapeutic frameworks that are used alongside psychedelics in the lab or in the clinic. Based on a narrative analysis of the treatment manual and post...

Importance Novel treatments for opioid use disorder (OUD) are needed to address both the ongoing opioid epidemic and long-standing barriers to existing OUD treatments that target the endogenous μ-opioid receptor (MOR) system. The goal of this review is to highlight unique clinical trial design considerations for the study of emerging treatments for...

Increasing vaccine utilization is critical for numerous diseases, including COVID-19, necessitating novel methods to forecast uptake. Behavioral economic methods have been developed as rapid, scalable means of identifying mechanisms of health behavior engagement. However, most research using these procedures is cross-sectional and evaluates predict...

The acute subjective effects of psychedelics are responsive to users’ expectations and surroundings (i.e., “set and setting”). Accordingly, a great deal of thought has gone into designing the psychosocial context of psychedelic administration in clinical settings. But what theoretical paradigms inform these considerations about set and setting? Her...

Operant behavioral economic methods are increasingly used in basic research on the efficacy of reinforcers as well as in large-scale applied research (e.g., evaluation of empirical public policy). Various methods and strategies have been put forward to assist discounting researchers in conducting large-scale research and detecting irregular respons...

Background: Preliminary data suggest that psilocybin-assisted treatment produces substantial and rapid antidepressant effects in patients with major depressive disorder (MDD), but little is known about long-term outcomes. Aims: This study sought to examine the efficacy and safety of psilocybin through 12 months in participants with moderate to seve...

The role of human behavior to thwart transmission of infectious diseases like COVID-19 is evident. Psychological and behavioral science are key areas to understand decision-making processes underlying engagement in preventive health behaviors. Here we adapt well validated methods from behavioral economic discounting and demand frameworks to evaluat...

The past decade has witnessed a rapid growth of research on the basic science and clinical understanding of psychedelics. This chapter provides an overview of the human behavioral pharmacology of psychedelics focusing on three prototypic classic psychedelics—psilocybin, lysergic acid diethylamide (LSD), and dimethyltryptamine (DMT). A brief histori...

Delay discounting and operant demand are two behavioral economic constructs that tend to covary, by degree, with cigarette smoking status. Given historically robust associations between adverse health outcomes of smoking, a strong preference for immediate reinforcement (measured with delay discounting), and excessive motivation to smoke cigarettes...

Behavioral economics offers unique tools for assessing value and motivation associated with college drinking. Tasks that model changes in consumption as a function of price (operant demand) or the decline in an outcome’s subjective value as a function of time-to-occurrence (delay discounting) provide valuable information that may efficiently supple...

Background: Delay discounting assessments typically involve choices between an immediate outcome and a larger amount of the same outcome after a delay. Real-world choices, however, more often involve qualitatively different alternatives. The primary aim of this study was to examine single- and cross-commodity discounting of money, alcohol, and cann...

Several pilot studies have provided evidence supporting the potential of classic psychedelics like psilocybin in the treatment of substance use disorders (SUDs). If larger trials confirm efficacy, classic psychedelic-assisted psy- chotherapy may eventually be integrated into existing addiction treatments such as cognitive behavioral therapy, contin...

Verbal reports of drug effects are often used in behavioral pharmacology. Two reports related to reinforcement are drug use (Harford, 1978; Liu et al., 2018) frequency and drug preference. Anecdotally, some individuals may specify a favorite/preferred drug (e.g., psilocybin) despite using another drug more frequently (e.g., tobacco). Research compa...

Condom use substantially reduces unwanted pregnancies and sexually transmitted infections. While condom availability is a significant public health priority, effects of condom availability constraints remain relatively under‐researched. The limited research on condom availability suggests two major barriers to use: (1) effort/costs and (2) delay to...

Background: Experiences with psychedelic drugs, such as psilocybin or lysergic acid diethylamide (LSD), are sometimes followed by changes in patterns of tobacco, opioid, and alcohol consumption. But, the specific characteristics of psychedelic experiences that lead to changes in drug consumption are unknown. Objective: Determine whether quantitativ...

As fatal overdoses from synthetic opioids continue to rise, we need to understand decision-making processes underlying heroin and synthetic opioid use. This study evaluated the influence of sample impurity and fatal overdose risk on hypothetical heroin use. Individuals who currently use heroin (n = 69) were recruited online. Participants completed...

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Psychedelic substances produce unusual and compelling changes in conscious experience which have prompted some to propose that psychedelics may provide unique insights explaining the nature of consciousness. At present, psychedelics, like other current scientific tools and methods, seem unlikely to provide information relevant to the so-called “har...

Background Growing evidence suggests psilocybin, a naturally occurring psychedelic, is a safe and promising pharmacotherapy for treatment of mood and substance use disorders when administered as part of a structured intervention. In most trials to date, psilocybin dose has been administered on a weight-adjusted basis rather than the more convenient...

Attention-deficit/hyperactivity disorder (ADHD) is associated with increased risk of detrimental life outcomes. Recent research also indicates that ADHD is associated with sexual risk behavior, such as unprotected sex. Some risky sexual behaviors may be driven, in part, by preference for immediate rewards, referred to as delay discounting, which is...

Mounting evidence supports the serotonin 2A receptor agonist psilocybin as a psychiatric pharmacotherapy. Little research has experimentally examined how session “set and setting” impacts subjective and therapeutic effects. We analyzed the effects of the musical genre played during sessions of a psilocybin study for tobacco smoking cessation. Parti...

This viewpoint identifies pitfalls in the study of psychedelic compounds, including those that pose challenges for the potential use of psychedelics as medicines. They are as follows: (1) Sloppiness regarding use of the term “consciousness”. (2) Inappropriate introduction of religious/spiritual beliefs of investigators or clinicians. (3) Clinical b...

Psychedelics have shown great promise in modern clinical trials for treating various psychiatric conditions. As a transdiagnostic treatment that exerts its effects through subjective experiences that leave enduring effects, it is akin to psychotherapy. To date, there has been insufficient discussion of how psychedelic therapy is similar to and diff...

Economic vulnerability, such as homelessness and unemployment, contributes to HIV risk among U.S. racial minorities. Yet, few economic-strengthening interventions have been adapted for HIV prevention in this population. This study assessed the feasibility of conducting a randomized clinical trial of a 20-week microenterprise intervention for econom...

Importance: Major depressive disorder (MDD) is a substantial public health burden, but current treatments have limited effectiveness and adherence. Recent evidence suggests that 1 or 2 administrations of psilocybin with psychological support produces antidepressant effects in patients with cancer and in those with treatment-resistant depression. O...

Salvinorin A (SA) is a κ-opioid receptor agonist and atypical dissociative hallucinogen found in Salvia divinorum. Despite the resurgence of hallucinogen studies, the effects of κ-opioid agonists on human brain function are not well-understood. This placebo-controlled, within-subject study used functional magnetic resonance imaging for the first ti...

Behavioral processes underlying sexual behavior are important for understanding normal human functioning and risk behavior leading to sexually transmitted infections (STIs). This systematic review examines delay and probability discounting in human sexual behavior through synthesis of 50 peer-reviewed, original research articles. Sixteen studies fo...

As cannabis policy changes, there is an urgent need to understand interactions between cannabis and alcohol couse. An online sample of 711 adult past-month cannabis and alcohol users completed both single-item hypothetical purchasing tasks for cannabis and alcohol and cross-commodity purchasing tasks assessing adjusting-price cannabis with concurre...

Correlational evidence has linked methamphetamine use and HIV sexual risk behavior, but the direct effects of methamphetamine on sexual desire and sexual decision making in humans have not been tested. This study was designed to test the effect of methamphetamine administration on sexual desire and hypothetical condom-use decisions as measured by t...

We demonstrate through theoretical, empirical, and sociocultural evidence that the concept of impulsivity fails the basic requirements of a psychological construct and should be rejected as such. Impulsivity (or impulsiveness) currently holds a central place in psychological theory, research, and clinical practice and is considered a multifaceted c...

As more states in the US legalize cannabis for recreational and medical use, the public health impact of cannabis may increase if regularly co-consumed with alcohol or tobacco. We used a behavioral economics framework to examine how public health messaging influences cannabis, alcohol, and tobacco purchasing. Participants who reported current canna...

RationaleAlthough both psilocybin and dextromethorphan (DXM) produce psychedelic-like subjective effects, rates of non-medical use of psilocybin are consistently greater than DXM.Objective New data are presented from a study of psilocybin and DXM relevant to understanding the features of psilocybin subjective effects that may account for its higher...

The last years have seen an increasing interest in research on hallucinogenic drugs, like psilocybin and LSD. Similar developments were observed for the entactogen MDMA. During the 1950s and 1960s, this field was in the focus, and relatively broad investigations of psilocybin and LSD were conducted, both in basic and clinical research. In this era,...

Hypothetical purchase tasks allow for rapid assessment of behavioral economic demand for numerous commodities and are useful in evaluating reinforcer pathologies, such as substance and behavioral addiction. Currently, there is not a task for evaluating demand for sex without requiring implicit engagement in sex work. The current study used a novel...

Background Experiences of having an encounter with seemingly autonomous entities are sometimes reported after inhaling N,N-dimethyltryptamine. Aim The study characterized the subjective phenomena, interpretation, and persisting changes that people attribute to N,N-dimethyltryptamine-occasioned entity encounter experiences. Methods Two thousand, f...

Delay discounting reflects the systematic reduction in the value of a consequence by delay to delivery. Theoretical and empirical work suggests that delay discounting is a key behavioral mechanism underlying substance use disorder. Existing work on cannabis use, however, is mixed with many studies reporting null results. The purpose of this review...

Background Cannabinoids may potentiate opioid analgesia and therefore could be used to reduce reliance on opioids for analgesia. Aims The current study evaluated whether the concurrent availability of cannabis influences opioid consumption using a behavioral economic demand framework. Methods An online survey assessed cannabis and opioid use freq...

Background Observational data and preliminary studies suggest serotonin 2A agonist psychedelics may hold potential in treating a variety of substance use disorders (SUDs), including opioid use disorder (OUD). Aims The study aim was to describe and analyze self-reported cases in which naturalistic psychedelic use was followed by cessation or reduct...

Background: Ecstasy typically contains adulterants in addition to, or in lieu of, MDMA which may pose a greater risk to users than MDMA itself. The current study aimed to evaluate the effectiveness of adulterant-related informational prompts in reducing Ecstasy use using a novel probability discounting task. Methods: An online sample of past-mon...

Understanding factors associated with cocaine use disorder is important given its public health impact. One factor is delay discounting (devaluation of future consequences). Cocaine users have shown greater delay discounting of money rewards than non–cocaine users. But underexamined are factors known to affect discounting, such as the sign (reward...

Patterns of tobacco, opioid, and alcohol consumption have been shown to change following a psychedelic experience. However, the specific characteristics of psychedelic experiences that do and do not lead to changes in drug consumption are unknown. We asked 1141 individuals who quit or reduced using alcohol, cannabis, opioids, or stimulants followin...

Cigarette pack graphic warning labels (GWLs) are associated with increased knowledge of tobacco-related harms; scant research has evaluated their effects on behavior among vulnerable populations. We used a behavioral economic approach to measure the effects of GWLs and price on hypothetical cigarette purchasing behavior among HIV-positive smokers....

Delay discounting (DD) refers to the rate at which a reward loses value when there is a delay in receiving it. • DD tasks measure individual preference for Larger Later (LL) rewards in which a larger reward is available at a delay versus Smaller Sooner (SS) rewards in which a smaller reward is available more rapidly. • Eating restraint in anorexia...

Background There has been growing interest in using oxytocin as a pharmacotherapy for psychiatric disorders, including substance use disorder. Limited data exist regarding oxytocin’s reinforcing efficacy, which is a necessary consideration for novel pharmacotherapies, especially in substance-using populations. Aims This study aimed to determine th...

Background: Recent reports of naturalistic psychedelic use outside of clinical settings suggest potential positive effects substance use disorders. However, still unknown are the mechanisms of psychedelic-assisted behavior change and what variables might predict who will benefit from psychedelic-assisted behavior change. Methods: This secondary ana...

This presentation was given as part of the Psychedelics as Behavior Change Agents symposium at APA 2019 and describes behavioral economic analyses of enduring changes following psilocybin administration.

Cocaine dependence constitutes a significant public health concern. This randomized, double-blind, placebo-controlled trial tested a novel approach to reducing cocaine use among cocaine-dependent individuals with d-cycloserine, a drug known to enhance learning and some learning-based therapies. Urine samples and cocaine craving were assessed across...

Background: Economic vulnerability, such as homelessness and unemployment, contributes to the HIV risk among racial minorities in the U.S., who are disproportionately infected. Yet, few economic-strengthening interventions have been adapted for HIV prevention in economically-vulnerable African-American young adults. Engaging Microenterprise for Re...

Objective: Sexual delay discounting describes the decreased likelihood of condom-protected sex if a condom is not immediately available, which can be quantitatively summarised using the Sexual Delay Discounting Task (SDDT). The present studies determined the extent to which condom use likelihood as assessed by the SDDT is associated with self-repor...

Understanding the mechanisms driving cocaine use disorder, despite its long-term negative consequences, is important. One factor is delay discounting (devaluation of future consequences). Cocaine users have shown greater delay discounting of money rewards than non-cocaine users. But research has not examined factors known to affect discounting, suc...

This analysis evaluated how past-30-day Ecstasy users made decisions regarding use of potentially-impure Ecstasy samples based on the perceived harm of impurities.

Background: Text messages offer the potential to better evaluate HIV behavioral interventions using repeated longitudinal measures at a lower cost and research burden. However, they have been underused in US minority settings. Objective: This study aims to examine the feasibility of assessing economic and sexual risk behaviors using text message...

BACKGROUND Text messages offer the potential to better evaluate HIV behavioral interventions using repeated longitudinal measures at a lower cost and research burden. However, they have been underused in US minority settings. OBJECTIVE This study aims to examine the feasibility of assessing economic and sexual risk behaviors using text message sur...

Delay discounting is sometimes discussed as a trait variable – a pre-existing characteristic people bring to a situation. At the extreme, a trait approach suggests an association between discounting across outcomes characteristics (e.g., amount, commodity, and gain/loss). A trait approach would predict related, but not necessarily equivalent, disco...

Delay discounting is sometimes discussed as a trait variable – a pre-existing characteristic people bring to a situation. A trait approach suggests an association between discounting across outcomes characteristics (e.g., amount, commodity, and gain/loss). A trait approach would predict related, but not necessarily equivalent, discounting across ch...

Psilocybin has shown to increase social cooperation in an Ultimatum Game and empathy for social partners. Unexamined is whether psilocybin impacts social discounting or responding in a Prisoner’s Dilemma game, and how enduring any changes might be. We administered psilocybin to participants (N = 75) who also started a program of meditation/spiritua...

Background: Major Depressive Disorder (MDD) is a prevalent condition that confers substantial public health burden. Current approved treatments, including pharmacotherapy and psychotherapy, are limited in effectiveness and adherence. Recent evidence suggests that one or two administrations of psilocybin under psychologically supported conditions pr...

Background: Meta-analysis of randomized studies using lysergic acid diethylamide (LSD) for alcohol use disorder (AUD) showed large, significant effects for LSD efficacy compared to control conditions. Clinical studies suggest potential anti-addiction effects of LSD and mechanistically-related classic psychedelics for alcohol and other substance use...

Supplemental doc providing more info on background, methods, results, and discussion.

Naturally occurring and psychedelic drug–occasioned experiences interpreted as personal encounters with God are well described but have not been systematically compared. In this study, five groups of individuals participated in an online survey with detailed questions characterizing the subjective phenomena, interpretation, and persisting changes a...

Questionnaire of naturally occurring (i.e. non-drug) God encounter experiences. (PDF)

Supporting information tables A, B, C, D, E, F, G, H, I, and J provide estimated means and standard errors of the estimate for data presented in the published manuscript in Tables 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12, respectively. (PDF)

Questionnaire of God encounter experiences occasioned by classic psychedelics. (PDF)

The present study sought to examine factors associated with psychedelic-occasioned reductions in drug use to better understand possible mechanisms through which psychedelic use may exert such effects. Respondents (n=444; White=82%, male=79%, US resident=67%; cannabis users=37%; opioid users=35%; stimulant users=28%) self-identified as experiencing...

Lack of condom use among youth is a major contributor to the spread of sexually transmitted infections (STIs) including HIV/AIDS, which has lifelong deleterious health consequences. College students (N = 262) completed the Sexual Probability Discounting Task in which participants reported their likelihood of condom use under various probabilities o...