Psychedelic therapy for depressive symptoms: A systematic review and meta-analysis

Content analysis of Reddit posts about coadministration of selective serotonin reuptake inhibitors and psilocybin mushrooms

RATIONALE

Treatments with the serotonergic psychedelic psilocybin are being investigated for multiple neuropsychiatric disorders. Because many patients with these disorders use selective serotonin reuptake inhibitors (SSRIs), understanding interactions between psilocybin and SSRIs is critical for evaluating the safety, efficacy, and scalability of psilocybin-based treatments. Current knowledge about these interactions is limited, as most clinical psilocybin research has prohibited concomittant SSRI use.

OBJECTIVES

We aimed to explore potential interactions between psilocybin and SSRIs by characterizing peoples' real-world experiences using psilocybin mushrooms and SSRIs together.

METHODS

We conducted a systematic search of Reddit for posts describing psilocybin mushroom and SSRI coadministration. We identified 443 eligible posts and applied qualitative content analysis to each.

RESULTS

8% of posts reported negative physical or psychological effects resulting from coadministration. These included 13 reports that may reflect serotonin toxicity, and 1 concerning for a psychotic/manic episode. 54% of posts described reduced intensity of the acute psilocybin experience, but 39% reported unchanged intensity with SSRI coadministration.

CONCLUSIONS

Psilocybin's interactions with SSRIs are likely complex and may depend on multiple factors. Prospective studies are needed to evaluate whether psilocybin treatments are reliably safe and effective in the setting of SSRI use.

Management of Depression in Adults: A Review

Importance

Approximately 9% of US adults experience major depression each year, with a lifetime prevalence of approximately 17% for men and 30% for women.

Observations

Major depression is defined by depressed mood, loss of interest in activities, and associated psychological and somatic symptoms lasting at least 2 weeks. Evaluation should include structured assessment of severity as well as risk of self-harm, suspected bipolar disorder, psychotic symptoms, substance use, and co-occurring anxiety disorder. First-line treatments include specific psychotherapies and antidepressant medications. A network meta-analysis of randomized clinical trials reported cognitive therapy, behavioral activation, problem-solving therapy, interpersonal therapy, brief psychodynamic therapy, and mindfulness-based psychotherapy all had at least medium-sized effects in symptom improvement over usual care without psychotherapy (standardized mean difference [SMD] ranging from 0.50 [95% CI, 0.20-0.81] to 0.73 [95% CI, 0.52-0.95]). A network meta-analysis of randomized clinical trials reported 21 antidepressant medications all had small- to medium-sized effects in symptom improvement over placebo (SMD ranging from 0.23 [95% CI, 0.19-0.28] for fluoxetine to 0.48 [95% CI, 0.41-0.55] for amitriptyline). Psychotherapy combined with antidepressant medication may be preferred, especially for more severe or chronic depression. A network meta-analysis of randomized clinical trials reported greater symptom improvement with combined treatment than with psychotherapy alone (SMD, 0.30 [95% CI, 0.14-0.45]) or medication alone (SMD, 0.33 [95% CI, 0.20-0.47]). When initial antidepressant medication is not effective, second-line medication treatment includes changing antidepressant medication, adding a second antidepressant, or augmenting with a nonantidepressant medication, which have approximately equal likelihood of success based on a network meta-analysis. Collaborative care programs, including systematic follow-up and outcome assessment, improve treatment effectiveness, with 1 meta-analysis reporting significantly greater symptom improvement compared with usual care (SMD, 0.42 [95% CI, 0.23-0.61]).

Conclusions and Relevance

Effective first-line depression treatments include specific forms of psychotherapy and more than 20 antidepressant medications. Close monitoring significantly improves the likelihood of treatment success.

A rapid narrative review of the clinical evolution of psychedelic treatment in clinical trials

Pre-prohibition psychedelic research with complex psychiatric patients generated a wealth of treatment methodologies and practices, providing invaluable clinical insights pertaining to the medical administration of psychedelics in various mental health diagnoses. Building upon these early studies, which lack the rigor and research tools available today, contemporary psychedelic research has focused on investigating the safety and efficacy of psychedelics in randomized controlled trials via psychometric measures and symptom assessments. Both then and now, the treatment context and the role of clinicians in psychedelic treatment has been recognized as an essential feature for positive patient outcomes. To broaden the knowledge base of modern psychedelic research and support the training of clinicians conducting medically supervised psychedelic research studies, this paper provides a review of pre-prohibition clinical research narratives pertaining to the phenomenology of psychedelic treatment and the role of the non-pharmacological treatment factors in the patient experience. Lastly, this paper explores a range of clinician perspectives and psychological interventions employed in pre-prohibition psychedelic research to inform future research directions and best practice guidelines.

Attitudes on Psychedelics in a Sample of Croatian Mental Health Professionals: A Cross-Sectional National Survey Study

For some time now, there has been an increased interest in psychedelics among scientists and mental health experts. Given that experts introduce therapy and advise patients, it is important to know their views. Therefore, the aim of our research was to examine and compare the attitudes of psychiatrists and psychologists toward psychedelics. We were interested in how they are formed and what is the role of personality in that process. We included 218 respondents, of which 92 were psychiatrists and 126 were psychologists. Attitudes toward psychedelics were examined using the Attitudes on Psychedelics Questionnaire. We used the Big Five Inventory to examine personality traits. On the Legal Use of Psychedelics subscale, it was shown that psychiatrists have more negative attitudes toward psychedelics (p = .033). Higher Openness (β = 0.184, p < .001) and lower Conscientiousness (β = -0.144, p = .009) contribute to positive attitudes toward psychedelics, as well as previous lifetime experience with psychedelics (β = 0.411, p < .001) and younger age (β = -0.278, p < .001). In conclusion, we can say that mental health professionals are open but also wary of psychedelics. Openness motivates them to learn. For this reason, additional education could have an impact on the attitudes of psychiatrists and psychologists and prepare them for the practical use of psychedelics.

Psychedelic 25H-NBOMe attenuates post-sepsis depression in rats

Sepsis-associated encephalopathy, which manifests in severe cognitive and depressive symptoms, is directly linked to neuroinflammation. Our study investigates the efficacy of 25H-NBOMe, a phenethylamine, in alleviating these symptoms, potentially offering an innovative treatment for post-sepsis depression. Wistar rats, weighing between 250-300 g, were subjected to cecal ligation and puncture (CLP) surgery to induce sepsis. Depressive-like behaviors were assessed using the forced swim test (FST) on either day 7 or 14 post-surgery, to establish the presence of depressive symptoms. The impact of 25H-NBOMe treatment was then evaluated, focusing on the head-twitch response (HTR), performance in the FST, and GFAP expression in the prefrontal cortex. Treatment with 25H-NBOMe resulted in significant behavioral changes, demonstrated by decreased immobility and increased swimming times in the FST, along with a rise in the HTR. These outcomes indicate a reduction in depressive-like symptoms post-sepsis and the psychoactive effects of the compound. Furthermore, a notable decrease in GFAP expression in the study highlights the compound's impact on mitigating sepsis-induced astrogliosis. This study demonstrates the effectiveness of 25H-NBOMe, a psychedelic in the phenethylamine class, in treating post-sepsis depression and reducing astrogliosis. However, the psychedelic nature of 25H-NBOMe calls for further investigation into similar compounds with less psychoactive impact, crucial for advancing treatment options for neuropsychiatric symptoms following sepsis.

In the new era of psychedelic assisted therapy: A systematic review of study methodology in randomized controlled trials

Recent years have seen a resurgence in randomized, placebo controlled trials (RCTs) utilizing non-classical psychedelics (e.g. 3,4-methyl enedioxy methamphetamine [MDMA]), and classical psychedelics (e.g. psilocybin, lysergic acid diethylamide [LSD], and N,N-dimethyltryptamine [DMT/ayahuasca]) in conjunction with assisted therapy (AT) for psychiatric disorders. A notable methodological challenge in psychedelic AT, however, is the complexity of blinding procedures. The lack of efficacious blinding can introduce considerable response bias, reduce internal validity, and compromise participant retention. This systematic review examines design and blinding techniques in RCTs utilizing psychedelics and placebo for the treatment of psychiatric disorders. The aim of this work is to identify factors that may inform future RTC design for conducting psychedelics research. We conducted a systematic review of PubMed, MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), Psycinfo, Embase, and Web of Science Core Collection to examine: (1) placebo selection, (2) study design, and (3) integrity of blinding measures. Sixteen publications were identified as meeting the criteria for a systematic review. Our findings suggest that traditional placebo administration is insufficient to control for expectancy confounds. Consequently, experimental methodology that limits personnel unblinding and the use of an active placebo are important considerations when designing prospective clinical studies involving psychedelics.

Tripping into the unknown: Exploring the experiences of first-time LSD users through global drug survey insights

BACKGROUND

The recreational use of LSD, a synthetic psychedelic drug, has surged in recent years, coinciding with a renewed research focus on its potential psychotherapeutic properties.

AIM

This study aims to describe the experiences and perceptions of individuals engaging in LSD use for the first time, derived from a large international sample.

METHODS

This study utilised 2018 Global Drug Survey data collected from 6 November 2017 to 10 January 2018. Participants who initiated LSD use in the preceding 12 months answered questions on their experiences, social settings, harm-reduction behaviours, and demographics. Descriptive statistics were employed, and characteristics of those seeking emergency medical treatment (EMT) and those not planning further LSD use were compared with other respondents.

RESULTS

Among 3340 respondents who used LSD in the past year, their first-time experiences generally exceeded expectations, with 97.7% expressing excitement. Adverse and unwanted side effects were rarely reported, and only 17 individuals needed EMT. Feelings of fear were reported by most (64.1%), but only very mildly and not enough to put them off from wanting to use LSD again.

DISCUSSION

Although the occurrence of unwanted side effects seems low and the LSD experience is generally pleasurable, vigilance amid the rising illicit use of LSD through harm-reduction education is still important in preventing possible risks.

Attitudes of European psychiatrists on psychedelics: a qualitative study

Introduction and aim

It is important to understand how mental health practitioners view recent findings on psychedelic-assisted psychotherapy (PAP) as there is potential this treatment may be incorporated into clinical practice. The aim of our study was to explore how psychiatrists who are not involved in psychedelic research and who are located in the European region perceive psychedelics and PAP.

Methods

We conducted online semi-structured interviews with 12 psychiatry specialists and psychiatry trainees from 8 European countries. Data were analyzed using a general inductive approach informed by codebook thematic analysis.

Results

Based on the interviews, we developed four main themes and 14 sub-themes, including (1) Psychedelics hold potential, (2) Psychedelics are dangerous, (3) Future of psychedelics is uncertain, and (4) Psychiatry is ambivalent toward psychedelics.

Discussion

Our respondents-psychiatrists acknowledged the potential of PAP but remained cautious and did not yet perceive its evidence base as robust enough. Education on psychedelics is lacking in medical and psychiatric training and should be improved to facilitate the involvement of mental health experts in decision-making on PAP.

Personality traits explain the relationship between psychedelic use and less depression in a comparative study

Interest in psychedelics is increasing due to the potential for improved mental health and quality of life. However, adverse effects on mental health are still a concern. Personality traits have been suggested to both influence the psychedelic experience and mental health, and even be changed by psychedelic use. The present study describes for the first time a national sample of Swedish psychedelic users (n = 400) compared to a sex and age-matched control-group of non-users (n = 400) regarding mental health variables (depression, insomnia, problematic alcohol and drug use, and dissociation) and personality (Big Five). Data was collected in an online survey including individuals from 16 years of age who had at least one psychedelic experience. The main results reported psychedelic users as less depressed (Patient Health Questionnaire-9; PHQ-9) (d = - 0.29) and having more use of drugs (Drug Use Disorders Identification Test; DUDIT) (d = 1.27). In the Big Five personality traits, openness differed notably (d = 1.72), and the between-group effects in PHQ-9 were explained by lower neuroticism. Our findings reveal that psychedelic users report less depression and higher drug use, and this is partly due to personality traits. These results have implications on how we view psychedelic users and the use of psychedelic drugs.

Efficacy of psilocybin for treating symptoms of depression: systematic review and meta-analysis

OBJECTIVE

To determine the efficacy of psilocybin as an antidepressant compared with placebo or non-psychoactive drugs.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Five electronic databases of published literature (Cochrane Central Register of Controlled Trials, Medline, Embase, Science Citation Index and Conference Proceedings Citation Index, and PsycInfo) and four databases of unpublished and international literature (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, ProQuest Dissertations and Theses Global, and PsycEXTRA), and handsearching of reference lists, conference proceedings, and abstracts.

DATA SYNTHESIS AND STUDY QUALITY

Information on potential treatment effect moderators was extracted, including depression type (primary or secondary), previous use of psychedelics, psilocybin dosage, type of outcome measure (clinician rated or self-reported), and personal characteristics (eg, age, sex). Data were synthesised using a random effects meta-analysis model, and observed heterogeneity and the effect of covariates were investigated with subgroup analyses and metaregression. Hedges' g was used as a measure of treatment effect size, to account for small sample effects and substantial differences between the included studies' sample sizes. Study quality was appraised using Cochrane's Risk of Bias 2 tool, and the quality of the aggregated evidence was evaluated using GRADE guidelines.

ELIGIBILITY CRITERIA

Randomised trials in which psilocybin was administered as a standalone treatment for adults with clinically significant symptoms of depression and change in symptoms was measured using a validated clinician rated or self-report scale. Studies with directive psychotherapy were included if the psychotherapeutic component was present in both experimental and control conditions. Participants with depression regardless of comorbidities (eg, cancer) were eligible.

RESULTS

Meta-analysis on 436 participants (228 female participants), average age 36-60 years, from seven of the nine included studies showed a significant benefit of psilocybin (Hedges' g=1.64, 95% confidence interval (CI) 0.55 to 2.73, P<0.001) on change in depression scores compared with comparator treatment. Subgroup analyses and metaregressions indicated that having secondary depression (Hedges' g=3.25, 95% CI 0.97 to 5.53), being assessed with self-report depression scales such as the Beck depression inventory (3.25, 0.97 to 5.53), and older age and previous use of psychedelics (metaregression coefficient 0.16, 95% CI 0.08 to 0.24 and 4.2, 1.5 to 6.9, respectively) were correlated with greater improvements in symptoms. All studies had a low risk of bias, but the change from baseline metric was associated with high heterogeneity and a statistically significant risk of small study bias, resulting in a low certainty of evidence rating.

CONCLUSION

Treatment effects of psilocybin were significantly larger among patients with secondary depression, when self-report scales were used to measure symptoms of depression, and when participants had previously used psychedelics. Further research is thus required to delineate the influence of expectancy effects, moderating factors, and treatment delivery on the efficacy of psilocybin as an antidepressant.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023388065.

The effect of psychedelics on the level of brain-derived neurotrophic factor: A systematic review and meta-analysis

BACKGROUND

Recent interest in the potential therapeutic effects of psychedelics has led to investigations into their influence on molecular signaling pathways within the brain.

AIMS

Integrated review and analysis of different studies in this field.

METHODS

A systematic search was conducted across international databases including Embase, Scopus, Web of Science, and PubMed from inception to 9 July 2023. Eligibility criteria encompassed published and peer-reviewed studies evaluating changes in brain-derived neurotrophic factor (BDNF) levels after psychedelic consumption.

OUTCOMES

A total of nine studies were included in our study. The meta-analysis demonstrated significantly higher BDNF levels in psychedelic consumers compared to healthy controls, with a pooled standardized mean difference of 0.26 (95% CI: 0.10-0.42, I2 = 38.51%, p < 0.001). Leave-one-out analysis indicated robustness in results upon removal of individual psychedelics. No significant publication bias was observed. The results highlight the potential influence of psychedelics on neuroplasticity by altering BDNF levels.

CONCLUSIONS

More precisely, the documented rise in BDNF levels indicates a neurobiological mechanism by which psychedelics could enhance synaptic plasticity and foster the growth of neurons. Given the limited data available on this topic, the conclusions remain uncertain. Consequently, we highly recommend additional research with more extensive sample sizes to yield more reliable evidence in this field.

Phase 1, placebo-controlled, single ascending dose trial to evaluate the safety, pharmacokinetics and effect on altered states of consciousness of intranasal BPL-003 (5-methoxy-N,N-dimethyltryptamine benzoate) in healthy participants

AIMS

To investigate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of BPL-003, a novel intranasal benzoate salt formulation of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), in healthy participants.

METHODS

In all, 44 psychedelic-naïve participants enrolled in the double-blind, placebo-controlled single ascending dose study (1-12 mg BPL-003). Concentrations of 5-MeO-DMT and its pharmacologically active metabolite, bufotenine, were determined in plasma and urine. PD endpoints included subjective drug intensity (SDI) rating, the Mystical Experience Questionnaire (MEQ-30) and the Ego Dissolution Inventory (EDI).

RESULTS

BPL-003 was well tolerated at doses up to 12 mg. There were no serious adverse events (AEs), and most AEs were mild; the most common being nasal discomfort, nausea, headache and vomiting. 5-MeO-DMT was rapidly absorbed and eliminated; the median time to peak plasma concentration was approximately 8-10 min and the mean terminal elimination half-life was <27 min. 5-MeO-DMT systemic exposure increased approximately dose-proportionally, while plasma bufotenine concentrations and urinary excretion of 5-MeO-DMT and bufotenine were negligible. The intensity of the SDI ratings was associated with plasma 5-MeO-DMT concentrations. MEQ-30 and EDI scores generally increased with the BPL-003 dose; 60% of participants had a 'complete mystical experience' at 10 and 12 mg doses. Profound and highly emotional consciousness-altering effects were observed with BPL-003, with a rapid onset and short-lasting duration.

CONCLUSION

The novel intranasal formulation of BPL-003 was well tolerated with dose-proportional increases in PK and PD effects. The short duration of action and induction of mystical experiences suggest clinical potential, warranting further trials.

CLINICAL TRIAL REGISTRATION

NCT05347849.

Psychedelic substitution: altered substance use patterns following psychedelic use in a global survey

Introduction

Recent research suggests that psychedelics may have potential for the treatment of various substance use disorders. However, most studies to date have been limited by small sample sizes and neglecting to include non-North American and European populations.

Methods

We conducted a global, cross-sectional online survey of adults (n = 5,268, 47.2% women) self-reporting past or current psychedelic use and investigated whether psychedelic use was associated with changes in use of other substances.

Results

Nearly three-quarters (70.9%; n = 3,737/5,268) reported ceasing or decreasing use of one or more non-psychedelic substances after naturalistic psychedelic use. Among those with previous use, 60.6% (n = 2,634/4,344) decreased alcohol use, 55.7% (n = 1,223/2,197) decreased antidepressant use, and 54.2% (n = 767/1,415) decreased use of cocaine/crack. Over a quarter of the sample indicated that their decrease in substance use persisted for 26 weeks or more following use of a psychedelic. Factors associated with decreased use included a motivation to either decrease one's substance use or self-treat a medical condition. Importantly, 19.8% of respondents also reported increased or initiated use of one or more other substances after psychedelic use, with illicit opioids (14.7%; n = 86/584) and cannabis (13.3%; n = 540/4,064) having the highest proportions. Factors associated with increased substance use included having a higher income and residing in Canada or the US.

Discussion

Although limited by cross-sectional study design, this large observational study will help inform future studies aiming to investigate the relationship between substance use patterns and psychedelic use.

Efficacy and acceptability of psilocybin for primary or secondary depression: A systematic review and meta-analysis of randomized controlled trials

Introduction

Psilocybin is a classic psychedelics, which has been shown to have antidepressant effects by many studies in recent years. In this study, we aim to evaluate the efficacy, acceptability and tolerability of psilocybin in the treatment of primary (major depressive disorder) or secondary (experiencing distress related to life-threatening diagnoses and terminal illness) depression.

Methods

We searched PubMed, EMBASE, Web of Science, Cochrane Library and ClinicalTrials.gov for clinical trials of psilocybin for depression (updated to 4 October, 2023). Effect size Hedges' g was used as an indicator of efficacy, and other outcomes included response rate, drop-out rate, and adverse events.

Results

A total of 10 studies were finally included in systematic review. 8 studies were included in the meta-analysis, involving a total of 524 adult patients, and produced a large effect size in favor of psilocybin (Hedge's g =-0.89, 95% CI -1.25~-0.53, I² = 70.19%, P<0.01). The therapeutic effects of psilocybin increase with increasing doses. Adverse events caused by psilocybin are generally transient and reversible, but serious adverse events also may occur.

Discussion

Our study shows that psilocybin has both short-term and long-term antidepressant effects and holds promise as a potential complementary or alternative therapy for depression, probably. Further research may reveal more about its therapeutic potential.

Giving Consent to the Ineffable

A psychedelic renaissance is currently taking place in mental healthcare. The number of psychedelic-assisted therapy trials is growing steadily, and some countries already grant psychiatrists special permission to use psychedelics in non-research contexts under certain conditions. These clinical advances must be accompanied by ethical inquiry. One pressing ethical question involves whether patients can even give informed consent to psychedelic-assisted therapy: the treatment's transformative nature seems to block its assessment, suggesting that patients are unable to understand what undergoing psychedelic-assisted therapy actually means for them and whether it aligns with their values. The present paper argues that patients often have sufficient knowledge to give informed consent because they know that they want to change their negative status quo and that psychedelic-assisted therapy offers an effective way to do so. Accordingly, patients can understand what the transformative nature of psychedelic-assisted therapy means for them and a make a value-aligned choice even if they are unable to anticipate the manifestation of a psychedelic experience.

Antidepressant- and anxiolytic-like activities and acute toxicity evaluation of the Psilocybe cubensis mushroom in experimental models in mice

ETHNOPHARMACOLOGY RELEVANCE

Central nervous system (CNS) diseases can be diverse and usually present with comorbidity, as in the case of depression and anxiety. Despite alternatives like Psilocybe mushrooms for mental health there is no basic research to evidence their CNS benefits.

AIM OF THE STUDY

To evaluate the anxiolytic- and antidepressant-like effects, as well as the acute toxicity of P. cubensis mushroom.

MATERIAL AND METHODS

First, the acute toxicity (LD50) of P. cubensis (2000 mg/kg) was determined after the esophageal (p.o.) and intraperitoneal (i.p.) route of administration. The rota-rod test and electroencephalogram (EEG) were included to assess CNS toxicity in free moving mice. Anxiolytic (ambulatory or exploratory and rearing behaviors) and antidepressant behavioral responses were assayed in the open-field, plus-maze, and forced swimming test, respectively, after administration of 1000 mg/kg, p.o., of the whole P. cubensis mushroom or the polar aqueous (AQ) or methanolic (MeOH) extractions (1, 10, and/or 100 mg/kg, i.p.) in comparison to the reference drugs buspirone (4 mg/kg, i.p.), fluoxetine and/or imipramine (10 mg/kg, s.c. and i.p., respectively). A chemical analysis of the AQ and MeOH extractions was performed to detect psilocybin and/or psilocin by using UHPLC.

RESULTS

Neurotoxic effects of P. cubensis mushroom administered at high doses were absent in mice assessed in the rota-rod test or for EEG activity. A LD50 > 2000 mg/kg was calculated by p.o. or i.p. administration. While significant and/or dose-response antidepressant-like effects were produced with the whole P. cubensis mushroom, p.o., and after parenteral administration of the AQ or MeOH extractions resembling the effects of the reference drugs. Behavioral responses were associated with an anxiolytic-like effect in the open-field as corroborated in the plus-maze tests. The presence of psilocybin and psilocin was mainly characterized in the AQ extraction.

CONCLUSION

Our results provide preclinical evidence of the anxiolytic- and antidepressant-like effects of the P. cubensis mushroom without producing neurotoxicity after enteral or parenteral administration, where psilocybin and psilocin were identified mainly after AQ extraction. This study reinforces the benefits of the P. cubensis mushroom in mental health and therapy for anxiety and depression.

Ononin ameliorates depression-like behaviors by regulating BDNF-TrkB-CREB signaling in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Ononin is a flavonoid compound found in several medicinal plants, including Astragalus membranaceus, Sophora flavescens, and Ononis spinosa. These plants have been traditionally used in various parts of the world for their medicinal properties, including anti-inflammatory, antioxidant, and antitumor effects. Major depression is a common, long-lasting, and recurrent psychiatric disorder with a high suicide rate. Naturally occurring flavonoids treat depression via poorly understood mechanisms.

AIM OF THE STUDY

The present study aimed to determine whether ononin conferred an antidepressant-like effect in PC12 cell models and chronic mild stress (CMS)-induced depressive rat models and to explore its possible mechanisms.

MATERIALS AND METHODS

Depression-related behaviors were measured using sucrose preference, tail suspension and open-field tests. Furthermore, to explore these mechanisms, we employed in vitro and in vivo assay methods, including neurite outgrowth, western blotting, quantitative RT-PCR, and staining methods.

RESULTS

Treatment with ononin or BDNF significantly increased PC12 cells' neuronal growth and differentiation. Furthermore, ononin promotes the activation of TrkB and growth factors and upregulates the PI3K/Akt and BDNF/TrkB/CREB signaling pathways. The in vitro results were consistent with CMS-induced depressive rat models, in which ononin treatment significantly decreased depression-like behaviors and activated TrkB, growth factors, and BDNF/TrkB/CREB signaling pathways in the frontal cortex and hippocampus. Depression-induced microscopic alterations in the frontal cortex and hippocampus of rats with CMS-induced depression were also mitigated following ononin treatment.

CONCLUSION

Based on these findings, we suggest that ononin is a promising antidepressant candidate for treating depression.

Trauma-Informed Care in Psychedelic Therapy Research: A Qualitative Literature Review of Evidence-Based Psychotherapy Interventions in PTSD and Psychedelic Therapy Across Conditions

Introduction

Post-traumatic stress disorder (PTSD) is associated with significant patient burden. While pharmacotherapies and evidence-based psychotherapy interventions (EBPI) are effective, studies consistently highlight inadequate outcomes and high treatment dropout. Psychedelic therapy (PT) has shown preliminary promise across difficult-to-treat conditions, including MDMA-assisted therapy for PTSD, however trials of classical psychedelics in PTSD are lacking. Understanding patients' experiences of EBPI could help promote safety in PT.

Aim

To systematically review qualitative research on patients' subjective experience of EBPI for PTSD, and of PT, and examine areas of overlap and divergence between them.

Methods

Systematic literature searches for studies published between 2010 and 2023 were conducted on OVID, PubMed, Web of Science, and PsycInfo. Included were original studies in English that presented qualitative data of patient experiences of EBPI in PTSD, or PT for any indication. Extracted data from included studies were analysed using thematic synthesis. Syntheses were completed separately for EBPI and PT, before similarities and differences between the therapies were identified.

Results

40 research articles were included for review: 26 studies on EBPI for PTSD, and 14 studies on PT. EBPI studied were CBT, EMDR, CPT and PE. Psychedelic compounds studied were psilocybin, ibogaine, LSD, MDMA and ketamine, for treatment of substance use disorders, anxiety relating to physical illness, depression, and PTSD. Core themes from patient experiences of EBPI: 1) patient burden in PTSD treatment; 2) readiness; 3) key mechanisms of change; 4) psychological safety and trust. Themes identified in the review of PT: 1) indirect trauma processing; 2) reorganisation of self-narratives via processes of relatedness and identification; 3) key treatment characteristics.

Conclusion

This study suggests overlap between patients' experience of EBPI and PT in terms of key mechanisms of change, the importance of psychological safety and readiness to engage in treatment. Trauma-informed care paradigms and practices may improve safety and acceptability of PT research.

TAAR1 as an emerging target for the treatment of psychiatric disorders

Trace amines, a group of amines expressed at the nanomolar level in the mammalian brain, can modulate monoamine transmission. The discovery of and the functional research on the trace amine-associated receptors (TAARs), especially the most well-characterized TAAR1, have largely facilitated our understanding of the function of the trace amine system in the brain. TAAR1 is expressed in the mammalian brain at a low level and widely distributed in the monoaminergic system, including the ventral tegmental area and substantial nigra, where the dopamine neurons reside in the mammalian brain. Growing in vitro and in vivo evidence has demonstrated that TAAR1 could negatively modulate monoamine transmission and play a crucial role in many psychiatric disorders, including schizophrenia, substance use disorders, sleep disorders, depression, and anxiety. Notably, in the last two decades, many studies have repeatedly confirmed the pharmacological effects of the selective TAAR1 ligands in various preclinical models of psychiatric disorders. Recent clinical trials of the dual TAAR1 and serotonin receptor agonist ulotaront also revealed a potential efficacy for treating schizophrenia. Here, we review the current understanding of the TAAR1 system and the recent advances in the elucidation of behavioral and physiological properties of TAAR1 agonists evaluated both in preclinical animal models and clinical trials. We also discuss the potential TAAR1-dependent signaling pathways and the cellular mechanisms underlying the inhibitory effects of TAAR1 activation on drug addiction. We conclude that TAAR1 is an emerging target for the treatment of psychiatric disorders.

A Proposal to Study the Safety and Efficacy of Psilocybe cubensis in Preclinical and Clinical Studies as a Therapeutic Alternative for Major Depressive Disorder

The pharmacological treatment of depression consists of taking antidepressant drugs for prolonged periods; its modest therapeutic effect can often be associated with significant adverse effects, while its discontinuation can lead to relapses. Psilocybin is today a novel and breakthrough therapy for major depression. It is a natural alkaloid in Psilocybe mushrooms, which are endemic to Mexico. Research on a larger scale is lacking in various populations, including the Mexican people. This proposal contemplates the experimental design of a preclinical (toxicity and pharmacological evaluation of an extract in mice) and clinical study by including the chemical analysis of a species of Psilocybe cubensis mushroom to characterize its main constituents. The clinical study will consider the safety evaluation by exploring tolerated doses of Psilocybe cubensis by measuring pharmacokinetic parameters after oral administration in healthy adults and an open trial on a sample of patients with major depressive disorder to assess the safety and efficacy of fully characterized Psilocybe cubensis in a two-single doses treatment, (with assisted psychotherapy), compared with the traditional care model at the Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz in Mexico City. This report presents the design of a research project with preclinical and clinical experimental components.

Predicting the Intensity of Psychedelic-Induced Mystical and Challenging Experience in a Healthy Population: An Exploratory Post-Hoc Analysis

Introduction

In psychedelic therapy, mystical as well as challenging experience may influence therapeutic outcome. However, predictors of such experience have not been sufficiently established. Determining predictors of their intensity is, therefore, potentially beneficial in targeting psilocybin therapy for depression.

Methods

In a post hoc data analysis of a Phase 1, randomised, double-blind, placebo-controlled, between-groups clinical trial, dosage, personality traits, affect, and individual data were analysed as possible clinical predictors. Eighty-nine healthy volunteers were randomised to receive a single dose of placebo, 10 mg of psilocybin, or 25 mg of psilocybin. ANOVA was used to analyse the relationship between dosage and mystical and/or challenging experience, and correlation analysis for all other variables.

Results

The intensity of both mystical and challenging experience was strongly associated with higher dosage. Age was negatively correlated with intensity of challenging experience. Correlation between identified personality traits and either mystical or challenging experience was minimal, with the exception of positive correlation between neuroticism and challenging experience at higher dose. Neither positive nor negative affect indicated correlation with the intensity of either type of experience.

Discussion

A limitation of this study is its post hoc, exploratory design; recommendations for further research are provided.

History repeating: guidelines to address common problems in psychedelic science

Research in the last decade has expressed considerable optimism about the clinical potential of psychedelics for the treatment of mental disorders. This optimism is reflected in an increase in research papers, investments by pharmaceutical companies, patents, media coverage, as well as political and legislative changes. However, psychedelic science is facing serious challenges that threaten the validity of core findings and raise doubt regarding clinical efficacy and safety. In this paper, we introduce the 10 most pressing challenges, grouped into easy, moderate, and hard problems. We show how these problems threaten internal validity (treatment effects are due to factors unrelated to the treatment), external validity (lack of generalizability), construct validity (unclear working mechanism), or statistical conclusion validity (conclusions do not follow from the data and methods). These problems tend to co-occur in psychedelic studies, limiting conclusions that can be drawn about the safety and efficacy of psychedelic therapy. We provide a roadmap for tackling these challenges and share a checklist that researchers, journalists, funders, policymakers, and other stakeholders can use to assess the quality of psychedelic science. Addressing today's problems is necessary to find out whether the optimism regarding the therapeutic potential of psychedelics has been warranted and to avoid history repeating itself.

Psychoactive substances 25H-NBOMe and 25H-NBOH induce antidepressant-like behavior in male rats

Ring-substituted phenethylamines are believed to induce psychedelic effects primarily by interacting with 5-hydroxytryptamine 2 (5-HT2A) receptors in the brain. We assessed the effect of the psychedelic substances 25H-NBOMe and 25H-NBOH on the depressive-like behavior of male adult rats. Naive Wistar rats were divided into groups to assess the effects of different doses (0.1 mg/kg, 1 mg/kg, and 3 mg/kg) of 25H-NBOMe and 25H-NBOH. The substances were administered intraperitoneally and the hallucinogenic properties were evaluated using the head twitch response test (HTR). Additionally, we assessed their locomotor activity in the open field test (OFT) and depressive-like behavior in the forced swimming test (FST). Our data demonstrated that all doses of synthetic psychedelic substances evaluated exhibited hallucinogenic effects. Interestingly, we observed that both 25H-NBOMe and 25H-NBOH produced a significantly greater motivation to escape in the FST, compared to the control group. Furthermore, we found no significant differences in locomotor activity during the OFT, except for the dose of 3 mg/kg, which induced a reduction in locomotion. This study provides new insights into a potential psychedelic substance, specifically by demonstrating the previously unknown antidepressant properties of a single dose of both 25H-NBOMe and 25H-NBOH. These findings contribute to the ongoing progress of experimental psychiatry toward developing safe and effective clinical practices in the field of psychedelics research.

Psychedelics, With a Focus on Psilocybin: Issues for the Clinician

There has been a burgeoning interest in psychedelics among the public, state legislatures, psychiatrists and other clinical providers, and within the research community. Increasing numbers of studies evaluating psychedelics for depression, anxiety, posttraumatic stress disorder, and substance use disorders have been conducted or are underway. While discussing psychedelics in general, the focus of this paper is on psilocybin and its mechanism, how it exerts a psychedelic effect, dosing, and a review of the treatment studies of psilocybin, which were primarily for treatment-resistant depression and cancer-related anxiety. Future directions and potential limitations of studying and regulating psilocybin and other psychedelics are also discussed.

Psychedelics for treatment resistant depression: are they game changers?

INTRODUCTION

A new era of treatment for adults with treatment-resistant depression (TRD), which involves psychedelic substances, is dawning. Emerging evidence indicates that psychedelics can exert antidepressant effects through multiple neurobiological and psychological mechanisms. However, it remains to be seen if these new treatments will revolutionize the treatment of TRD.

AREAS COVERED

The present review focuses on the efficacy of serotoninergic psychedelics psilocybin, lysergic acid diethylamide (LSD), N,N-dimethyltryptamine (DMT), ayahuasca, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and mescaline (3,4,5-trimethoxyphenethylamine), as well as 3,4-methylenedioxymethamphetamine (MDMA), for TRD. A systematic search was conducted for psilocybin in TRD as emerging trials had not yet been subject to review. A narrative review summarized findings on other psychedelics.

EXPERT OPINION

Psychedelic therapy has created a paradigm shift in the treatment of TRD, as it can maximize therapeutic benefits and minimize potential risks. Psilocybin holds promise as a potential game-changer in the treatment of TRD, with initial evidence suggesting a rapid antidepressant effect sustained for some responders for at least 3 months. Nevertheless, further adequately powered, double-blind, comparator-controlled trials are required to explore and clarify the mechanisms of action and long-term effects of psychedelics in TRD. Psychedelics also hold promise for other psychiatric conditions, such as bipolar depression and post-traumatic stress disorder.

Microbiome: The Next Frontier in Psychedelic Renaissance

The psychedelic renaissance has reignited interest in the therapeutic potential of psychedelics for mental health and well-being. An emerging area of interest is the potential modulation of psychedelic effects by the gut microbiome-the ecosystem of microorganisms in our digestive tract. This review explores the intersection of the gut microbiome and psychedelic therapy, underlining potential implications for personalized medicine and mental health. We delve into the current understanding of the gut-brain axis, its influence on mood, cognition, and behavior, and how the microbiome may affect the metabolism and bioavailability of psychedelic substances. We also discuss the role of microbiome variations in shaping individual responses to psychedelics, along with potential risks and benefits. Moreover, we consider the prospect of microbiome-targeted interventions as a fresh approach to boost or modulate psychedelic therapy's effectiveness. By integrating insights from the fields of psychopharmacology, microbiology, and neuroscience, our objective is to advance knowledge about the intricate relationship between the microbiome and psychedelic substances, thereby paving the way for novel strategies to optimize mental health outcomes amid the ongoing psychedelic renaissance.