Psychiatry research
November 1, 2023
Sipan Haikazian, David C J Chen-Li, Danica E Johnson et al.
121 citations
A systematic review and meta-analysis of 13 studies (686 participants) found that psilocybin therapy produced a large reduction in depressive symptoms compared to control conditions, with a standardized mean difference of -0.78. Response and remission rates were also significantly higher with psilocybin. Open-label trials showed robust decreases in depression after psilocybin administration. The findings suggest antidepressant efficacy for psilocybin-assisted psychotherapy, but the authors note that further studies are needed to confirm safety and efficacy and to optimize treatment protocols.
Journal of psychiatric research
July 1, 2021
Ashley N Siegel, Shakila Meshkat, Katie Benitah et al.
101 citations
A review of clinical trials registered on clinicaltrials.gov as of December 3, 2020, shows that 70 studies are evaluating psychedelics (excluding ketamine) for psychiatric disorders. Most studies focus on MDMA (45.7%) and psilocybin (41.4%), with fewer investigating ayahuasca, LSD, ibogaine, salvia divinorum, 5-MeO-DMT, and DMT fumarate. MDMA and psilocybin are primarily studied for PTSD and major depressive disorder; LSD for depression, anxiety, and severe somatic disorders; ibogaine for substance use disorders; and 5-MeO-DMT and DMT for major depressive disorder. Only 21 of the 70 studies had published results; most are ongoing.
Med (New York, N.Y.)
March 8, 2024
Joshua D Rosenblat, Shakila Meshkat, Zoe Doyle et al.
97 citations
Psilocybin-assisted psychotherapy (PAP) is feasible for patients with complex, treatment-resistant depression, including those with bipolar II disorder and baseline suicidality. In a randomized trial with 30 adults, those receiving immediate PAP showed greater reductions in depression severity (MADRS) compared to a waitlist control, with a large effect size (Hedge's g = 1.07). Adverse events were transient and no serious adverse events occurred. Repeated doses over six months were associated with further improvement. The findings suggest PAP can be safely delivered to this population and warrants further study.
Brain sciences
June 4, 2023
Muhammad Youshay Jawad, Saleha Qasim, Menglu Ni et al.
46 citations
Ketamine shows promise as a treatment for bipolar depression, though evidence remains weak. A scoping review of 10 clinical studies (5 randomized controlled trials and 5 open-label studies) found that ketamine was generally tolerable, with minimal risk of triggering manic or hypomanic episodes, and demonstrated some effectiveness in reducing depressive symptoms and suicidality. The treatment may be particularly useful for patients with treatment-resistant bipolar depression. However, more research is needed to establish ketamine's role in both acute and maintenance treatment phases, and to study its potential for preventing recurrence and suicidal behavior.
Journal of affective disorders
July 1, 2024
Cameron N Calder, Angela T H Kwan, Kayla M Teopiz et al.
31 citations
Ketamine is effective for adults with treatment-resistant depression. A systematic review of 21 placebo-controlled randomized trials with 2042 participants calculated the number needed to treat (NNT) for racemic ketamine: 7 at 4 hours, 3 from one day to one week, and 9 at four weeks. Esketamine had an NNT of 2 at one day and 11 at four weeks. Numbers needed to harm indicated low risk. The NNTs under 10 across observation intervals are considered highly clinically meaningful for this difficult-to-treat disorder. Limitations include potential functional unblinding and selective reporting bias.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
August 1, 2024
Roger S McIntyre, Istvan Bitter, Jozefien Buyze et al.
30 citations
In the ESCAPE-TRD trial, esketamine nasal spray caused treatment-emergent adverse events more often than quetiapine extended release (91.9% versus 78.0%), but these events were typically mild or moderate and transient: 92.0% resolved the same day, and only 4.2% of patients discontinued esketamine due to adverse events compared with 11.0% for quetiapine. The median proportion of days with adverse events was lower with esketamine (11.9% versus 21.3%). Along with greater efficacy, esketamine's tolerability profile supports its use for treatment-resistant depression.
Journal of affective disorders
June 15, 2024
Gia Han Le, Sabrina Wong, Sebastian Badulescu et al.
25 citations
A systematic review examined how serotonergic psychedelics (psilocybin, LSD) and ketamine affect brain wave patterns measured by EEG and MEG in people with major depressive disorder, treatment-resistant depression, and healthy controls. Ketamine and psychedelics both increase theta power in depressed individuals. In healthy controls and depressed persons, both drug classes decrease alpha, beta, and delta power. Ketamine also increases gamma power in both groups. Theta power specifically rises in those with major depressive disorder when given psychedelics. The studies varied in patient populations, dosing, and measurement devices. The findings support disease models involving altered network connectivity and may guide future treatment discovery.
The American journal of psychiatry
January 1, 2025
Roger S McIntyre, Angela T H Kwan, Rodrigo B Mansur et al.
23 citations
Psychedelics show promise for treating difficult-to-treat psychiatric disorders like major depressive disorder, treatment-resistant depression, and posttraumatic stress disorder, with preliminary evidence also supporting efficacy in tobacco and alcohol use disorders. However, concerns exist about the interpretability and translatability of study results due to insufficiently characterized short- and long-term safety, abuse liability, and the essentiality of the psychedelic experience and psychological support. This overview reviews methodological aspects affecting inferences and interpretation of extant psychedelic studies and provides guidance for future research and development critical to study interpretation and clinical implementation.
Journal of psychiatric research
August 1, 2024
Noah Chisamore, Danica Johnson, Margery J Q Chen et al.
21 citations
Psilocybin-assisted psychotherapy shows promise for treating depression and distress in life-threatening illnesses, but a systematic review of 28 clinical trial protocols reveals substantial variability and inconsistency in therapeutic approaches beyond the basic framework of preparatory, dosing, and integration sessions. The review found no validated or universally agreed-upon protocol, with frequent lack of clarity in descriptions of therapy models, duration, and number of sessions. Future studies need to define and report psychotherapeutic components more clearly to identify the safest and most effective approaches.
Journal of affective disorders
April 1, 2024
Sabrina Wong, Angela T H Kwan, Kayla M Teopiz et al.
19 citations
A systematic review of randomized controlled trials compared the clinical efficacy of psilocybin and esketamine in adults with treatment-resistant depression. 25 mg of psilocybin significantly reduced depressive symptoms at 21 days post-dose, with a number needed to treat (NNT) of 5. Psilocybin-induced nausea had a number needed to harm (NNH) of 5. Fixed doses of esketamine (56 mg and 84 mg) showed significant effects at 28 days post-dose, with NNTs of 7. Esketamine-induced headache, nausea, dizziness, and dissociation had NNHs below 10. The preliminary results may reflect only a small portion of the patient population and require replication and longer-term studies. Both agents showed clinically meaningful NNT estimates and acceptable NNH profiles, underscoring their clinical relevance for treatment-resistant depression.
CNS drugs
October 1, 2022
Niloufar Pouyan, Zahra Halvaei Khankahdani, Farnaz Younesi Sisi et al.
16 citations
A systematic review of psilocybin research organized by the Research Domain Criteria (RDoC) framework found that psilocybin has beneficial effects across multiple domains, particularly on positive valence systems, negative valence systems, and social processes. Short-term (23 assessments) and long-term (15 assessments) benefits were reported for positive valence systems. For the negative valence system, 12 outcome measures indicated increased fear, 19 showed no significant effect, and 7 parameters indicated lowered sustained threat over the long term. Thirty-four outcome measures revealed short-term alterations in social systems, including enhanced perception and understanding of others and affiliation. Cognitive systems findings mostly reported dyscognitive effects. Seven studies suggested transdiagnostic effects.
Journal of clinical psychopharmacology
Nicole Ledwos, Joshua D Rosenblat, Daniel M Blumberger et al.
16 citations
A critical appraisal of clinical trials on serotonergic psychedelics for major depressive disorder and end-of-life distress finds that current evidence is low-level due to methodological limitations. Small randomized trials of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy to an active comparator, with similar preliminary positive effects for single-dose ayahuasca in treatment-resistant depression and lysergic acid diethylamide for end-of-life distress. Adverse events were mild and transient. However, small homogenous samples, expectancy bias, functional unblinding, and lack of standardized psychotherapy limit all studies. Psychedelics should remain experimental interventions used within clinical trials.
Pharmaceuticals (Basel, Switzerland)
January 24, 2025
John E Donello, Roger S McIntyre, Donald B Pickel et al.
14 citations
Plastogens are a class of therapeutics that rapidly promote changes in neuroplasticity. Ketamine, a notable example, is an N-methyl-D-aspartate receptor (NMDAR) antagonist with rapid and long-term antidepressant effects but also psychotomimetic and dissociative side effects. Stinels—rapastinel, apimostinel, and zelquistinel—are plastogens with improved safety and tolerability profiles. This review clarifies the mechanism of stinels, defining them as positive allosteric modulators of NMDAR activity with a novel regulatory binding site, contrasting with earlier descriptions of glycine-like partial agonists. The review presents the rationale for targeting NMDARs in treatment-resistant depression and other psychiatric conditions.
Journal of affective disorders
October 15, 2024
Angela T H Kwan, Joshua D Rosenblat, Rodrigo B Mansur et al.
13 citations
Ketamine and esketamine are increasingly prescribed for treatment-resistant mood disorders and suicide risk, but ketamine is also misused. Analyzing reports in the World Health Organization pharmacovigilance database up to January 2024, ketamine showed elevated reporting odds ratios for alcohol abuse (3.24), substance dependence (12.48), substance use disorder (170.44), substance abuse (2.94), drug dependence (2.88), drug use disorder (11.54), and drug abuse (2.85). Esketamine had reduced odds for substance abuse (0.41), drug dependence (0.083), and drug abuse (0.052), and no increased odds for any alcohol or substance misuse parameter. These associations do not establish causation.
Frontiers in psychiatry
January 1, 2022
Ryan Yip, Jennifer Swainson, Atul Khullar et al.
13 citations
Ketamine is increasingly used for treatment-resistant depression, but its intravenous administration often causes transient high blood pressure. Current psychiatric guidelines recommend aggressive monitoring and treatment of these hypertensive episodes. This review argues that those guidelines should be updated to align with standard best practices for managing hypertension, distinguishing between hypertensive emergency and asymptomatic hypertensive urgency. Adopting such an updated protocol could make ketamine therapy safer and more accessible for patients with depression.
Journal of affective disorders
August 1, 2025
Morgan C H Cheng, Christine E Dri, Hana Ballum et al.
12 citations
Ketamine and esketamine produce rapid antidepressant effects in major depressive disorder and treatment-resistant depression, but their impact on patient-reported quality of life has been unclear. A systematic review of five studies found that both agents improve quality of life measures on scales such as the WHOQOL-BREF, Assessment of Quality of Life 8D, and EuroQol-5 Dimension-5 Layers, with statistically significant results. However, the studies had an overall moderate risk of bias and varied in the quality-of-life scales used and study duration. Further research should examine effects on specific quality-of-life domains.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
April 1, 2025
Eduard Vieta, Nahida Ahmed, Celso Arango et al.
12 citations
Patients with treatment-resistant depression who received esketamine nasal spray experienced 43.2% more weeks with functional remission over 32 weeks compared to those taking quetiapine extended release, a difference of 2.0 weeks. Esketamine also led to an 11.9% reduction in productivity loss due to absenteeism and a 14.2% reduction in overall work productivity loss. Both treatments were taken alongside an ongoing SSRI or SNRI. The findings suggest that esketamine provides greater improvements in daily functioning and workplace productivity for this patient group.
Psychiatry research
May 1, 2024
Eric A Miller, Houtan Totonchi Afshar, Jyoti Mishra et al.
12 citations
Ketamine helps some patients with treatment-resistant depression, but predicting who will respond is difficult. Analyzing symptom trajectories from 120 patients treated with ketamine or esketamine in a real-world clinic, all symptoms improved on average, with depressed mood improving faster than low energy. A principal component analysis identified overall treatment response and a second component reflecting differences between affective and somatic symptoms. Logistic regression classifiers predicted overall response better than chance using baseline symptoms alone. By adjusting decision thresholds, models identified 22% of patients who would not respond with over 96% negative predictive value, potentially guiding treatment recommendations to avoid ineffective treatments.
Journal of psychopharmacology (Oxford, England)
April 1, 2024
Nelson B Rodrigues, David Chen-Li, Joshua D Di Vincenzo et al.
12 citations
Ketamine is a rapid antidepressant for people with treatment-resistant depression, but no reliable predictors of response have been identified. This study examined whether variants in the Val66Met and CYP2B6 genes predicted treatment outcomes in 85 participants with major depressive disorder who received four intravenous ketamine infusions. Participants showed significant overall reductions in depression, suicide, and anxiety, with 25% meeting response criteria and 15% meeting remission criteria. However, neither Val66Met nor CYP2B6 genotypes significantly predicted changes in depressive symptoms, suicidality, anxiety, or dissociation. The findings suggest that single-gene predictors are unlikely to be useful and that a broader genetic approach may be needed.
CNS drugs
December 1, 2023
Niloufar Pouyan, Farnaz Younesi Sisi, Alireza Kargar et al.
12 citations
A review of 28 clinical studies with 477 participants examined how lysergic acid diethylamide (LSD) affects reward processing, using the National Institute of Mental Health's Research Domain Criteria (RDoC) framework. LSD produced dose-dependent mood improvement in 20 short-term and 3 long-term studies. Its subjective and neural effects were linked to the 5-HT2A receptor. Animal studies suggested LSD could mildly reinforce conditioned place preference without aversion and reduce responsiveness to other rewards. Findings on reward learning were inconsistent but hinted at potential enhancements in associative learning. Reward valuation measures indicated possible reductions in effort expenditure for other reinforcers. The review identified areas for future research but noted limitations including diverse study designs not initially RDoC-oriented and potential bias from open-label human studies.
Journal of affective disorders
April 1, 2025
Angela T H Kwan, Moiz Lakhani, Kayla M Teopiz et al.
11 citations
An analysis of the FDA Adverse Event Reporting System found that reports of hepatobiliary disorders differ between ketamine and esketamine. Compared to acetaminophen, ketamine was associated with disproportionately lower reporting of hepatitis, liver injury, drug-induced liver injury, hepatic failure, and acute hepatic failure, but disproportionately higher reporting of hepatic function abnormalities and hepatic cytolysis. For esketamine, there was no disproportionate reporting of most hepatobiliary toxicities relative to acetaminophen, except for disproportionately higher reporting of hepatic failure. The authors recommend periodic monitoring of liver function tests and clinical surveillance for signs of hepatobiliary disease in individuals receiving chronic ketamine or esketamine, though causality has not been established.
Psychiatry research
January 1, 2022
Joshua D Di Vincenzo, Orly Lipsitz, Nelson B Rodrigues et al.
11 citations
A small proportion of people with treatment-resistant depression experience clinically significant worsening of symptoms during a course of intravenous ketamine, but the rate is very low—between 1.83% and 5.49% across infusion time points—and similar to that seen with conventional antidepressants. In a retrospective analysis of 164 adults (142 with unipolar depression and 22 with bipolar depression) who received four ketamine infusions over two weeks, no individuals with bipolar depression reported worsening. The findings suggest that symptomatic worsening with ketamine is uncommon, though the study's uncontrolled, single-center design limits certainty.
CNS spectrums
October 31, 2024
Sabrina Wong, Gia Han Le, Angela T H Kwan et al.
10 citations
A systematic review and meta-analysis of seven randomized controlled trials found that a single dose of esketamine given around childbirth significantly reduced the incidence of postpartum depression (PPD). Within one week of delivery, the odds of a PPD diagnosis were 70% lower for those who received esketamine compared to a control; between four and six weeks postpartum, the odds were 67% lower. The results suggest that esketamine may have preventive antidepressant effects during the postpartum period, with implications for both the mechanisms and clinical treatment of PPD.
CNS spectrums
January 17, 2025
Roger S McIntyre, Gregory Mattingly, Yordan Godinov et al.
9 citations
In adults with treatment-resistant depression, esketamine nasal spray combined with an oral antidepressant leads to higher remission rates than quetiapine extended-release combined with an oral antidepressant. Starting at week 8, 28.3% of esketamine-treated patients achieved remission compared to 18.6% on quetiapine, and by week 32, 55.7% versus 36.3%. Depressive symptoms improved more with esketamine from day 8 onward. Fewer patients stopped treatment due to side effects with esketamine (4.5%) than with quetiapine (10.1%). These results come from a secondary analysis of a randomized trial.
Psychedelic Medicine
November 18, 2024
Shakila Meshkat, Erica Kaczmarek, Zoe Doyle et al.
8 citations
In a small subgroup analysis of four adults with treatment-resistant depression associated with bipolar II disorder, two 25 mg doses of psilocybin combined with psychotherapy were associated with reductions in depressive symptoms. The average depression score on the Montgomery–Åsberg Depression Rating Scale dropped from 32.5 at baseline to 20.3 two weeks after the first dose, and to 19 two weeks after the second dose; at six months the average score was 21.3. Mania ratings remained stable, and no mania, hypomania, or psychosis occurred. The authors suggest psilocybin may improve depressive symptoms in bipolar II disorder but call for larger studies to confirm the findings.