Psychopharmacology
January 2, 2019
Thomas Anderson, Rotem Petranker, Daniel Rosenbaum et al.
171 citations
People who currently or formerly microdosed psychedelics like LSD or psilocybin reported lower dysfunctional attitudes and negative emotionality, and higher wisdom, open-mindedness, and creativity compared to non-microdosers. These differences were observed in an online observational study using self-report questionnaires and a creativity task. The findings suggest potential benefits of microdosing, but controlled experiments are needed to confirm safety and clinical efficacy.
Harm Reduction Journal
July 9, 2019
Thomas Anderson, Rotem Petranker, Adam Christopher et al.
130 citations
A mixed-methods study of an active microdosing community categorizes the experiences participants report, identifying high-potential avenues for future scientific research. The resulting taxonomy distills intervention targets from participant reports to help allocate research funding efficiently. Microdosing research complements full-dose psychedelic studies as clinical treatments and neuropharmacological mechanisms are developed. The framework aims to guide researchers and clinicians as experimental microdosing research begins in earnest.
Psychopharmacology
February 1, 2021
Richard J. Zeifman, Nikhita Singhal, Rafael G. Dos Santos et al.
79 citations
Suicidality is a major public health problem with few treatment options. In an open-label trial, 17 adults with recurrent major depressive disorder received a single dose of ayahuasca. Among the 15 who had suicidality at baseline, suicidality decreased acutely (within 40 to 180 minutes after administration) and remained lower at 1, 7, 14, and 21 days afterward. Post-acute effect sizes were large (Hedges' g = 1.31–1.75), with the largest effect at 21 days (g = 1.75). When administered in an appropriate context, ayahuasca may produce rapid and sustained reductions in suicidality. The authors call for randomized, double-blind studies with larger samples to confirm these early findings.
Journal of Psychopharmacology
February 28, 2020
Daniel Rosenbaum, Cory R. Weissman, Thomas Anderson et al.
75 citations
People who microdose psychedelics—taking small, non-hallucinogenic amounts of LSD or psilocybin—are less likely to report a history of substance use disorders or anxiety disorders than non-microdosers, but more likely to report recent recreational substance use. Among 909 participants recruited from Reddit, most microdosers used LSD (59.3%) or psilocybin (25.9%) on a one-day-on, two-days-off schedule. The findings suggest that microdosers differ from non-microdosers in psychiatric and substance-use profiles, and well-designed randomized controlled trials are needed to evaluate safety and potential benefits in clinical populations.
ACS Pharmacology & Translational Science
March 11, 2021
Richard J. Zeifman, Nikhita Singhal, Leah Breslow et al.
60 citations
Classic psychedelics such as psilocybin, ayahuasca, and LSD are being used more often and studied as a potential mental health treatment. Suicidality is a safety concern with these substances, yet they may also help reduce suicidal thoughts. A systematic review of 64 articles found mixed results for non-clinical use: some studies showed positive, negative, or no link between lifetime psychedelic use and suicidality. Early psychedelic therapy had some suicide cases, but it was unclear if therapy caused them. Recent clinical trials found no increased suicidality and preliminary evidence for acute and sustained decreases after treatment.
Psychedelic Med (New Rochelle)
March 12, 2024
Alexander Wen, Nikhita Singhal, Brett D. M. Jones et al.
36 citations
Blinding is especially difficult in randomized controlled trials of psychedelics because these drugs produce noticeable changes in consciousness. This systematic review of 50 papers from 48 clinical trials published between 1963 and January 2023 found that most studies were double-blinded, used within-subjects designs, and employed inert placebos. The majority did not report on whether blinding procedures were successful, and in those that did, blinding failed. To reduce unblinding and expectancy effects, the authors recommend using active placebos and dose-response or active comparator designs.
npj Mental Health Research
February 20, 2024
Kush V. Bhatt, Cory R. Weissman
29 citations
Psilocybin, a serotonergic psychedelic, produces lasting antidepressant effects, but its mechanism is unclear. Empathy and prosocial behavior may play a key role. This review examines how psilocybin affects empathy and prosocial behavior and proposes that it initiates a positive feedback loop involving these social processes, which could explain its enduring antidepressant benefits.
The Journal of Clinical Psychiatry
January 13, 2022
Richard J. Zeifman, Dengdeng Yu, Nikhita Singhal et al.
18 citations
A meta-analysis of 7 psychedelic therapy clinical trials found that, relative to baseline, psychedelic therapy was associated with large decreases in suicidality acutely (80–240 minutes) and at 1 day, 1–8 weeks, and 3–4 months (standardized mean differences ranging from −1.48 to −2.36). At 6 months, the effect was medium (SMD = −0.65). Reductions were significant at all time points except 7–8 weeks. Acute and post-acute elevations in suicidality were rare (6.5% and 3.0%, respectively). The authors note limitations including heterogeneous samples and interventions, and suggest that controlled trials specifically evaluating psychedelic therapy for suicidality may be warranted.
November 1, 2018
Thomas Anderson, Rotem Petranker, Daniel Rosenbaum et al.
11 citations
preprint
People who regularly consume small amounts of psychedelics like LSD or psilocybin—a practice called microdosing—report lower levels of dysfunctional attitudes and negative emotionality, and higher levels of wisdom, open-mindedness, and creativity compared to those who do not microdose. This pre-registered study, the first to investigate microdosing and mental health, recruited participants from online forums. Although promising, the findings are preliminary and warrant controlled experimental research to test safety and clinical efficacy. Microdosing may offer clinical benefits without the hallucinogenic effects of full-dose psychedelic therapy.
The Journal of Clinical Psychiatry
January 8, 2025
Ali Abdolizadeh, Brett D. M. Jones, Maryam Hosseini Kupaei et al.
2 citations
A systematic review of treatments for suicidality among psychiatric inpatients aged 18–65 found that intravenous ketamine produced the most consistent rapid reduction in suicidality among 14 pharmacologic trials. Among 35 nonpharmacologic trials—including chronotherapy, neurostimulation, and psychotherapies—results were mixed, with some interventions showing potential benefit, especially for mood, personality, and trauma-related disorders. Many studies had methodological limitations such as nonrandomized designs and lack of control groups. The review calls for larger, well-designed trials to confirm effectiveness.
The Journal of Clinical Psychiatry
May 9, 2022
Richard J. Zeifman, Dengdeng Yu, Nikhita Singhal et al.
2 citations
correction
In a meta-analysis of patient-level data on psychedelics and suicidality, two serious adverse events occurred that the original study authors deemed unrelated to the drug. One participant in a very low-dose psilocybin condition (1 mg/70 kg) completed suicide 11 days after administration, having reported boredom and left the session early. Another participant attempted suicide about two months after an active psilocybin dose (21–25.2 mg/70 kg), following a partner's sudden death and subsequent methamphetamine and crack cocaine use, with a brief psychotic episode. These events highlight the need for close monitoring of all participants during and after psychedelic therapy trials.
Translational Psychiatry
November 17, 2025
Noah Stapper, Lindsay L Benster, Sahit Menon et al.
1 citation
A systematic review of 24 clinical trials examined neurophysiological biomarkers linked to treatment-induced changes in suicidal ideation. Most studies were published within the past five years but showed methodological heterogeneity, including non-randomized designs and concurrent interventions. Despite limitations, findings suggest that the anterior cingulate cortex is involved in the anti-suicidal effects of intravenous ketamine, an effect absent with oral ketamine, possibly explaining intravenous ketamine's superior clinical effects. Improvements in suicidal ideation following electroconvulsive therapy and magnetic seizure therapy were associated with activity in the prefrontal cortex. These patterns may indicate that acute effects of intravenous ketamine and sustained effects of seizure therapies involve differential modulation of these brain regions.
Journal of Affective Disorders
November 1, 2026
Lindsay L Benster, Jordan N Kohn, Benjamin Wade et al.
In a real-world comparison of two FDA-approved treatments for treatment-resistant depression, intranasal esketamine led to faster improvement than repetitive transcranial magnetic stimulation (rTMS). Over 90 days, esketamine patients responded a median of 36 days versus 49 days for rTMS, and suicidal ideation resolved more quickly (median 9 vs. 26 days). However, by about 90 days, overall response and remission rates were similar between the groups (68.8% and 45.2% for esketamine; 59.4% and 40.1% for rTMS), suggesting a difference in speed rather than ultimate effectiveness. For rTMS, slower response was predicted by comorbid anxiety and benzodiazepine use, while former tobacco use predicted faster response. No such predictors were found for esketamine.
Pharmacology Research & Perspectives
May 10, 2026
Jessie Kim, Liam Lochhead, Cory R. Weissman
Interest in psychedelic-assisted therapy (PAT) is growing, prompting policy shifts toward legalization in many U.S. states. As PAT moves from controlled clinical trials to real-world practice, concerns arise about maintaining rigorous patient screening, treatment setting, and therapist support. Clinical trials use strict inclusion criteria and safety monitoring to minimize adverse events, but routine clinics may face pressure to lower standards, as seen in some for-profit ketamine clinics. Nonpharmacological factors like preparation, therapeutic rapport, and integration meaningfully shape outcomes. Standardized training, certification, and oversight, such as a FDA Risk Evaluation and Mitigation Strategy (REMS), could help balance safety and access. Successful implementation requires thorough screening, supportive environment, and careful regulation to realize PAT's potential in psychiatry.
Community mental health journal
April 1, 2026
Kush V. Bhatt, Joseph Friedman, Lindsay L Benster et al.
Recreational psychedelic use is increasing, but data on adverse events is limited. A retrospective chart review of emergency department visits at UC San Diego Medical Center from 2010 to 2023 identified 232 cases linked to LSD (35%), MDMA (30.2%), and psilocybin (24%). Patients were mostly young, white, and male. Common symptoms included agitation (25.9%) and anxiety (24.6%); 11.2% required psychiatric hospitalization. Factors associated with higher odds of hospitalization were concurrent cannabis use (odds ratio 10.9), history of bipolar disorder (odds ratio 12.67), and history of a primary psychotic disorder (odds ratio 17.10). Most psychedelic-related emergency visits are managed without hospitalization, but these specific vulnerabilities predict severe outcomes.
Psychiatry Research
February 19, 2026
Trisha Menon, Andy Lu, Akhilan Arulmozhi et al.
Ketamine, esketamine, repetitive transcranial magnetic stimulation (rTMS), and electroconvulsive therapy (ECT) are associated with reductions in suicidal ideation in people with major depressive disorder. The strongest evidence from randomized controlled trials supports rapid, short-term effects, particularly for ketamine and esketamine. Further research is needed to characterize the durability of these antisuicidal effects and to determine whether reductions in suicidal ideation translate into reduced severity of suicidal behavior.