This December, research looked into many different aspects of the psychedelic experience. A review paper put forth the argument on why psychedelics and nature (relatedness) should go hand in hand. Music during psychedelic-assisted therapy is at least as important and we saw the first investigation of different genres at the very end of this year.

How the world judges researchers who use psychedelics themselves was investigated in a survey study. The study showed that the integrity of a researcher could be negatively influenced, but only if the study participants hadn’t used psychedelics themselves.

A meta-analysis of MDMA-assisted psychotherapy for PTSD was favorable, but the effects were smaller than usually reported. Significant effects on PTSD (CAPS-IV) scores were found in two of the three dosing (75 & 125 mg, not 100 mg) conditions. Another study with MDMA found it to be safe to use for couples where one was battling with PTSD. This small (n=12) study found that it also significantly improved relationship and happiness scores.

Peering inside the brain was done by Andrea Luppi and colleagues in an fMRI study with LSD. This study added a better understanding over time of how subjective effects (e.g. ego dissolution) map onto the neurological changes. And if changes at this level (vs subjective effects) are needed is hotly debated following a paper that showed the potential of a non-hallucinogenic psychedelic analog.

Do also check out the final section with many papers on ketamine (for SI, PPD, TRD, and more), some good reviews of where psychedelic research stands, and the effects of psychedelics on racial trauma.

The potential synergistic effects between psychedelic administration and nature contact for the improvement of mental health

Authors: Sam Gandy, Matthias Forstmann, Robin L. Carhart-Harris, Christopher Timmermann, David Luke & Rosalind Watts

Published: 6 December 2020

One-sentence summary: This review (2020) of the psychedelic therapy and nature relatedness argues that both may work in synergy and that maximising nature relatedness during psychedelic therapy could provide added benefits.

“Therapeutic psychedelic administration and contact with nature have been associated with the same psychological mechanisms: decreased rumination and negative affect, enhanced psychological connectedness and mindfulness-related capacities, and heightened states of awe and transcendent experiences, all processes linked to improvements in mental health amongst clinical and healthy populations. Nature-based settings can have inherently psychologically soothing properties which may complement all stages of psychedelic therapy (mainly preparation and integration) whilst potentiating increases in nature relatedness, with associated psychological benefits. Maximising enhancement of nature relatedness through therapeutic psychedelic administration may constitute an independent and complementary pathway towards improvements in mental health that can be elicited by psychedelics.“

Further analysis.

MDMA-facilitated cognitive-behavioural conjoint therapy for posttraumatic stress disorder: an uncontrolled trial

Authors: Candice M. Monson, et al.

Published: 7 December 2020

One-sentence summary: This open-label study (n=12, 6 couples) describes the safety, tolerability, and efficacy of MDMA (75-100mg) in combination with cognitive-behavioral conjoint therapy (CBCT) where one half of the couple was battling with PTSD.

“Cognitive-behavioural conjoint therapy (CBCT) for PTSD has been shown to improve PTSD, relationship adjustment, and the health and well-being of partners. MDMA (3,4-methylenedioxymethamphetamine) has been used to facilitate an individual therapy for PTSD. This study was an initial test of the safety, tolerability, and efficacy of MDMAfacilitated CBCT. Six couples with varying levels of baseline relationship satisfaction in which one partner was diagnosed with PTSD participated in a condensed version of the 15-session CBCT protocol delivered over 7 weeks. There were two sessions in which both members of the couple were administered MDMA. All couples completed the treatment protocol, and there were no serious adverse events in either partner. There were significant improvements in clinician-assessed, patient-rated, and partner-rated PTSD symptoms (pre- to post-treatment/follow-up effect sizes ranged from d = 1.85–3.59), as well as patient depression, sleep, emotion regulation, and trauma-related beliefs. In addition, there were significant improvements in patient and partner-rated relationship adjustment and happiness (d =.64–2.79). These results are contextualized in relation to prior results from individual MDMA-facilitated psychotherapy and CBCT for PTSD alone. MDMA holds promise as a facilitator of CBCT to achieve more robust and broad effects on individual and relational functioning in those with PTSD and their partners.“

Further analysis.

A non-hallucinogenic psychedelic analogue with therapeutic potential

Authors: Lindsay P. Cameron, et al.

Published: 9 December 2020

One-sentence summary: This paper describes an analog to ibogaine (tabernanthalog) with similar therapeutic potential that is non-toxic, and non-psychedelic.

“The psychedelic alkaloid ibogaine has anti-addictive properties in both humans and animals1. Unlike most medications for the treatment of substance use disorders, anecdotal reports suggest that ibogaine has the potential to treat addiction to various substances, including opiates, alcohol and psychostimulants. The effects of ibogaine— like those of other psychedelic compounds—are long-lasting2, which has been attributed to its ability to modify addiction-related neural circuitry through the activation of neurotrophic factor signalling3,4. However, several safety concerns have hindered the clinical development of ibogaine, including its toxicity, hallucinogenic potential and tendency to induce cardiac arrhythmias. Here we apply the principles of function-oriented synthesis to identify the key structural elements of the potential therapeutic pharmacophore of ibogaine, and we use this information to engineer tabernanthalog—a water-soluble, non-hallucinogenic, non-toxic analogue of ibogaine that can be prepared in a single step. In rodents, tabernanthalog was found to promote structural neural plasticity, reduce alcohol- and heroin-seeking behaviour, and produce antidepressant-like effects. This work demonstrates that, through careful chemical design, it is possible to modify a psychedelic compound to produce a safer, non-hallucinogenic variant that has therapeutic potential.”

A day later two viewpoint articles (usually not featured) may be of interest in the context of this finding. ‘The Subjective Effects of Psychedelics Are Necessary for Their Enduring Therapeutic Effects‘ by David Yaden and Roland Griffiths, and ‘The Subjective Effects of Psychedelics May Not Be Necessary for Their Enduring Therapeutic Effects‘ by David Olson (co-author of the paper above).

Effect of lysergic acid diethylamide (LSD) on reinforcement learning in humans

Authors: Jonathan W. Kanen, Qiang Luo, Mojtaba R. Kandroodi, Rudolf N. Cardinal, Trevor W. Robbins, Robin L. Carhart-Harris & Hanneke E.M. den Ouden

Published: 9 December 2020

One-sentence summary: This placebo-controlled study (n=19), which also used computational modeling, argues that LSD (75μg) increased reward learning rates heightened plasticity, which in turn could be the mechanism through which psychedelics help reshape maladaptive (‘stuck’) patterns.

“The non-selective serotonin 2A (5-HT2A) receptor agonist lysergic acid diethylamide (LSD) holds promise as a treatment for some psychiatric disorders. Psychedelic drugs such as LSD have been suggested to have therapeutic actions through their effects on learning. The behavioural effects of LSD in humans, however, remain largely unexplored. Here we examined how LSD affects probabilistic reversal learning in healthy humans. Conventional measures assessing sensitivity to immediate feedback (“win-stay” and “lose-shift” probabilities) were unaffected, whereas LSD increased the impact of the strength of initial learning on perseveration. Computational modelling revealed that the most pronounced effect of LSD was enhancement of the reward learning rate. The punishment learning rate was also elevated. Increased reinforcement learning rates suggest LSD induced a state of heightened plasticity. These results indicate a potential mechanism through which revision of maladaptive associations could occur.”

Further analysis.

Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms

Authors: Antonio Inserra, Danilo De Gregorio & Gabriella Gobbi

Published online: 18 December 2020

One-sentence summary: This review presents the neurobiological therapeutic mechanisms by which psychedelics work, with a focus on outcomes on 1) neuroplasticity, 2) immune system, and 3) effects on neurotransmitter (-modulator) systems.

“Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergic acid diethylamide (LSD) are being investigated in several phase II and phase I clinical trials. Hence, the concept of psychedelics as therapeutics may be incorporated into modern society. Here, we discuss the main known neurobiological therapeutic mechanisms of psychedelics, which are thought to be mediated by the effects of these compounds on the serotonergic (via 5-HT_2A and 5-HT_1A receptors) and glutamatergic [via N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors] systems. We focus on 1) neuroplasticity mediated by the modulation of mammalian target of rapamycin-, brain-derived neurotrophic factor-, and early growth response-related pathways; 2) immunomodulation via effects on the hypothalamic-pituitary-adrenal axis, nuclear factor ĸB, and cytokines such as tumor necrosis factor-α and interleukin 1, 6, and 10 production and release; and 3) modulation of serotonergic, dopaminergic, glutamatergic, GABAergic, and norepinephrinergic receptors, transporters, and turnover systems. We discuss arising concerns and ways to assess potential neurobiological changes, dependence, and immunosuppression. Although larger cohorts are required to corroborate preliminary findings, the results obtained so far are promising and represent a critical opportunity for improvement of pharmacotherapies in psychiatry, an area that has seen limited therapeutic advancement in the last 20 years. Studies are underway that are trying to decouple the psychedelic effects from the therapeutic effects of these compounds.“

LSD alters dynamic integration and segregation in the human brain

Authors: Andrea I. Luppi, Robin L. Carhart-Harris, Leor Roseman, Ioannis Pappas, David K. Menon & Emanuel A. Stamatakisa

Published online: 19 December 2020

One-sentence summary: This fMRI study (2020) improves our understanding of how LSD changes brain function over time and how subjective effects (e.g. ego dissolution) map onto these changes.

“Investigating changes in brain function induced by mind-altering substances such as LSD is a powerful method for interrogating and understanding how mind interfaces with brain, by connecting novel psychological phenomena with their neurobiological correlates. LSD is known to increase measures of brain complexity, potentially reflecting a neurobiological correlate of the especially rich phenomenological content of psychedelic-induced experiences. Yet although the subjective stream of consciousness is a constant ebb and flow, no studies to date have investigated how LSD influences the dynamics of functional connectivity in the human brain. Focusing on the two fundamental network properties of integration and segregation, here we combined graph theory and dynamic functional connectivity from resting-state functional MRI to examine time-resolved effects of LSD on brain networks properties and subjective experiences. Our main finding is that the effects of LSD on brain function and subjective experience are non-uniform in time: LSD makes globally segregated sub-states of dynamic functional connectivity more complex, and weakens the relationship between functional and anatomical connectivity. On a regional level, LSD reduces functional connectivity of the anterior medial prefrontal cortex, specifically during states of high segregation. Time-specific effects were correlated with different aspects of subjective experiences; in particular, ego dissolution was predicted by increased small-world organisation during a state of high global integration. These results reveal a more nuanced, temporally-specific picture of altered brain connectivity and complexity under psychedelics than has previously been reported.“

A comparison of MDMA-assisted psychotherapy to non-assisted psychotherapy in treatment-resistant PTSD: A systematic review and meta-analysis

Authors: Benjamin J. G. Illingworth, Declan J. Lewis, Andrew T. Lambarth, Kate Stocking, James M. N. Duffy, Luke A. Jelen & James J. Rucker

Published: 20 December 2020

One-sentence summary: This systematic review and meta-analysis of MDMA-assisted therapy for PTSD, found that over four RCT’s (n=67), PTSD scores (CAPS-IV) were lower in the 75mg and 125mg groups (not 100mg), and depression scores (BDI) only in the 75mg group.

“Rationale: Novel, evidence-based treatments are required for treatment-resistant post-traumatic stress disorder (PTSD). 3,4-Methylenedioxymethamphetamine (MDMA) has beneficially augmented psychotherapy in several small clinical trials. Objective: To review the use of MDMA-assisted psychotherapy in treatment-resistant PTSD. Methods: Systematic searches of four databases were conducted from inception to February 2020. A meta-analysis was performed on trials which were double-blinded, randomised, and compared MDMA-assisted psychotherapy to psychotherapy and placebo. The primary outcomes were the differences in Clinician Administered PTSD Scale (CAPS-IV) score and Beck’s Depression Inventory (BDI). Secondary outcome measures included neurocognitive and physical adverse effects, at the time, and within 7 days of intervention. Results: Four randomised controlled trials (RCTs) met inclusion criteria. When compared to active placebo, intervention groups taking 75 mg (MD -46.90; 95% (confidence intervals) CI -8.78, -5.02), 125 mg (MD -20.98; 95% CI -34.35, -7.61) but not 100 mg (MD -12.90; 95% CI -36.09, 10.29) of MDMA with psychotherapy, had significant decreases in CAPS-IV scores, as did the inactive placebo arm (MD -33.20; 95% CI -40.53, -25.87). A significant decrease in BDI when compared to active placebo (MD -10.80; 95% CI -20.39, -1.21) was only observed at 75 mg. Compared to placebo, participants reported significantly more episodes of low mood, nausea and jaw-clenching during sessions and lack of appetite after 7 days. Conclusion: These results demonstrate potential therapeutic benefit with minimal physical and neurocognitive risk for the use of MDMA-assisted psychotherapy in TR-PTSD, despite little effect on Beck’s Depression Inventory. Better powered RCTs are required to investigate further.”

How psychedelic researchers’ self-admitted substance use and their association with psychedelic culture affect people’s perceptions of their scientific integrity and the quality of their research

Authors: Matthias Forstmann & Christina Sagioglou

Published: 25 December 2020

One-sentence summary: A three-part survey study (n=952) found that psychedelic use by (fictitious) researchers themselves led to lower ratings on integrity, but not the quality of research.

“Across three studies (total N = 952), we tested how self-admitted use of psychedelics and association with psychedelic culture affects the public’s evaluation of researchers’ scientific integrity and of the quality of their research. In Studies 1 and 2, we found that self-admitted substance use negatively affected people’s assessment of a fictitious researcher’s integrity (i.e. being unbiased, professional, and honest), but not of the quality of his research, or how much value and significance they ascribed to the findings. Study 3, however, found that an association with psychedelic culture (i.e. presenting work at a scientific conference that includes social activities stereotypically associated with psychedelic culture) negatively affected perceived research quality (e.g. less valid, true, unbiased). We further found that the latter effect was moderated by participants’ personal experience with psychedelic substances: only participants without such experience evaluated research quality more negatively when it was presented in a stereotyped context.”

Further analysis.

Set and Setting: A Randomized Study of Different Musical Genres in Supporting Psychedelic Therapy

Authors: Justin C. Strickland, Albert Garcia-Romeu & Matthew W. Johnson

Published: 29 December 2020

One-sentence summary: This further analysis of an open-label, counter-balanced study (n=10) with psilocybin (20-30mg/70kg) found that overtone-based music (e.g. gongs) was more effective than classical music (for smoking cessation, mystical experience – but only trends – very small sample size).

“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. Participants (N = 10) received psilocybin (20–30 mg/70 kg) in two sessions, each with a different musical genre (Western classical versus overtone-based), with the order counterbalanced. Participants chose one genre for a third session (30 mg/70 kg). Mystical experiences scores tended to be higher in overtone-based sessions than in Western classical sessions. Six of ten participants chose the overtone-based music for a third session. Biologically confirmed smoking abstinence was similar based on musical choice, with a slight benefit for participants choosing the overtone-based playlist (66.7% versus 50%). These data call into question whether Western classical music typically used in psychedelic therapy holds a unique benefit. Broadly, we call for experimentally examining session components toward optimizing psychedelic therapeutic protocols.“

Further analysis.

More Psychedelic Research Papers

Use CTRL/CMD+F to quickly search if anything relevant for you has been published this month.

• The ameliorating effects of Vitamin E on hepatotoxicity of ecstasy (in mice, given a lot of MDMA, protected from liver damage if also vitamin E was given)
• Rethinking enhancement substance use: A critical discourse studies approach (“… if we reframe all substance use as providing enhancement or achieving a self-improvement goal, we have the potential to destigmatise substance use and eliminate the over-simplistic binaries that surround it.“)
• Examining Changes in Personality Following Shamanic Ceremonial Use of Ayahuasca (decrease in neuroticism after Ayahuasca use)
• Strengthened beliefs under psychedelics (SEBUS)? (preprint, commentary on the infamous REBUS paper)
• Modulation of the functional connectome in major depressive disorder by ketamine therapy (resting-state functional connectivity of those with MDD after ketamine treatment trended towards those of healthy controls)
• Esketamine for Postpartum Suicidality (“ first case of rapid life-saving improvement in postpartum depression (PPD) with severe suicidal ideation/attempt following the introduction of esketamine injections after failing to achieve a response with antidepressants“)
• Does Body Mass Index Predict Response to Intravenous Ketamine Treatment in Adults with Major Depressive and Bipolar Disorder? Results from the Canadian Rapid Treatment Center of Excellence (“Pretreatment BMI did not predict response to IV ketamine, which was effective regardless of BMI.“)
• Psychedelic-assisted therapy for functional neurological disorders: A theoretical framework and review of prior reports (review of psychedelics for functional neurological disorders (FNDs))
• Synthesis and Characterization of 5-MeO-DMT Succinate for Clinical Use (process described for making lab-grade 5-MeO-DMT, 139g, 99.86% purity – also see this press release)
• Ketamine treatment for individuals with treatment-resistant depression: longitudinal qualitative interview study of patient experiences (qualitative reports up to 2 months later, “Some participants described hopelessness when treatment stopped working, paralleled by increased suicidal ideation for three participants. The transient nature and cost of treatment were problematic.“)
• The ritual use of ayahuasca during treatment of severe physical illnesses: a qualitative study (qualitative (n=14) study on psychological processes in ritualistic ayahuasca use during illness)
• The History of Psychedelics in Psychiatry (review by Nichols and Walter)
• Psychedelics and Psychotherapy (review by Nayak and Johnson)
• Psychedelics in Psychiatry-Keeping the Renaissance From Going Off the Rails (short commentary by David Yaden, Mary Yaden & Roland Griffiths)
• A Validated Method for the Simultaneous Determination of Methamphetamine and 3,4-Methylenedioxy- N-methamphetamine in Blood-Based Liquid Chromatography-Tandem Mass Spectrometry (method for accurate detection of MDMA, and meth)
• Free energy calculations of the functional selectivity of 5-HT2B G protein-coupled receptor (“This work quantifies ligand-induced conformational specificity and functional selectivity of 5-HT2B and presents a platform for high-throughput virtual screening of ligands and rational engineering of the ligand-bound molecular free energy landscape“)
• Toxicology and Analysis of Psychoactive Tryptamines (biased? review, toxicology of tryptamines, doesn’t LSD as most common example?)
• The entropic tongue: Disorganization of natural language under LSD (investigates language use under the influence of a medium (75μg) dosage of LSD, finds increased entropy)
• Subanesthetic dose of ketamine for the antidepressant effects and the associated cognitive impairments of electroconvulsive therapy in elderly patients-A randomized, double-blind, controlled clinical study (lower cognitive decline, but no significant differences between ECT and ECT + low-dose ketamine on depressive symptoms)
• Studying pre-treatment and ketamine-induced changes in white matter microstructure in the context of ketamine’s antidepressant effects (pilot study (n=13), identifies specific white matter properties that correlate with clinical outcomes 24 hours later)
• Gray matter volume of rostral anterior cingulate cortex predicts rapid antidepressant response to ketamine (fMRI study (n=33) on depressed patients, shows that grey matter volume (specifically rACC) correlates with clinical outcomes 24 hours later)
• Consciousness, Religion, and Gurus: Pitfalls of Psychedelic Medicine (viewpoint article by Matthew Johnson, identifies 1) wrong use of consciousness as term, 2) religious/spiritual beliefs of clinician, and 3) clinical boundaries as challenges)
• Investigation of the Structure–Activity Relationships of Psilocybin Analogues (investigation of 17 psilocybin analogs, in mice)
• Mystical-type experiences occasioned by ketamine mediate its impact on at-risk drinking: Results from a randomized, controlled trial (double-blind, placebo-controlled study (n=40) showed that mystical experience predicted alcohol)
• Psilocybin-Assisted Group Therapy and Attachment: Observed Reduction in Attachment Anxiety and Influences of Attachment Insecurity on the Psilocybin Experience (this follow-up study (n=18) to Anderson and colleagues (2020) finds that attachment anxiety, but not attachment avoidance, decreased significantly 3 months after psilocybin-assisted group therapy)
• Salvinorin A Does Not Affect Seizure Threshold in Mice (in mice, no effect of Salvinorin A on seizure test)
• Rapid and long-lasting antidepressant-like effects of ketamine and their relationship with the expression of brain enzymes, BDNF, and astrocytes (in mice, ketamine changed brain-derived neurotrophic factor (BDNF) up to 30 days later)
• Corticosterone as a Potential Confounding Factor in Delineating Mechanisms Underlying Ketamine’s Rapid Antidepressant Actions (in rats, “we observed an over 3-fold increase in corticosterone levels in both serum and brain tissue, within an hour of administration of low dose ketamine (10 mg/kg), but not with (2R, 6R)-hydroxynorketamine (HNK) (10 mg/kg), a ketamine metabolite shown to produce antidepressant-like action in rodents without inducing immediate side-effects.”)
• Neurochemical and Behavioral Effects of a New Hallucinogenic Compound 25B-NBOMe in Rats (in rats, investigation of effects like head twitch response and locomotion)
• Combination of Electroconvulsive Therapy Alternating With Intravenous Esketamine Can Lead to Rapid Remission of Treatment Resistant Depression (case study, ECT + ketamine for better effect than both alone)
• Describing the Unspeakable: Psychedelic Communication Technologies and the Development of a Posthuman Language (description of psychedelic communication and how this (may) go beyond our current language models)
• Entheogenic Experience and Spirituality (making a framework for spiritual experiences (less intense than mystical experiences) which is predicted by spiritual motivation(?) but not spiritual affiliation or practices)
• People of color in North America report improvements in racial trauma and mental health symptoms following psychedelic experiences (prospective survey, n=313, found significant and moderate (d = -.45) effect of psychedelics (LSD, MDMA) on racial trauma, also reported on Ohio State website)
• Antidepressant actions of ketamine engage cell-specific translation via eIF4E (study in knockout mice, “The antidepressant activity of the drugs is mediated by 4E-BP2 in excitatory neurons, and 4E-BP1 and 4E-BP2 in inhibitory neurons.“)
• Rapid and long-lasting antidepressant-like effects of ketamine and their relationship with the expression of brain enzymes, BDNF, and astrocytes (in mice, ketamine “changed brain BDNF and GFAP expressions 30 days after a single administration“)
• Subanesthetic ketamine infusions for suicide ideation in patients with bipolar and unipolar treatment refractory depression (“Ketamine produced a significant reduction in SI as early as one hour (71.1%) and up to 1-week post-infusion (60.4%), accompanied by a reduction in overall depressive symptoms which were maintained until the 4^th week.“)
• Ketamine as an adjunctive therapy for major depression – a randomised controlled pragmatic pilot trial (this randomized study (n=25) found no difference in depression scores (HRSD-24) between ketamine and midazolam (benzodiazepine medication))
• Acute Lysergic Acid Diethylamide Does Not Influence Reward-Driven Decision Making of C57BL/6 Mice in the Iowa Gambling Task (in mice, no effect found on reward-driven decision-making)
• Differential effects of propofol and ketamine on critical brain dynamics (brain study on monkeys, tested if criticality of brain function is lowered under ketamine (not much) and propofol (more so))
• A Systematic Review on the Efficacy of Intravenous Racemic Ketamine for Bipolar Depression (five studies (n=110) were finally analysed in this systematic review, found improvements in depression scores, suicidal ideation, and anhedonia)
• Neural network models for DMT-induced visual hallucinations (by Schartner and Timmermann)
• The Effects of Daytime Psilocybin Administration on Sleep: Implications for Antidepressant Action (interesting study on how psilocybin may influence sleep, specifically this study found later onset of REM sleep)
• A Dendrite-Focused Framework for Understanding the Actions of Ketamine and Psychedelics (opinion paper, focus on action at dendrites of classical psychedelics and ketamine)
• The role of dissociation in ketamine’s antidepressant effects (“Presently, the literature does not support the conclusion that dissociation is necessary for antidepressant response to ketamine.“)
• Ketamine Normalizes the Structural Alterations of Inferior Frontal Gyrus in Depression (MRI scans 24 hours pre/post ketamine infusion, n=50, some changes found only in MDD group, not MDD/PTSD nor healthy controls)
• Low Dose Ketamine Infusion for Comorbid Posttraumatic Stress Disorder and Chronic Pain: A Randomized Double-Blind Clinical Trial (both ketamine and ketorolac proved to be effective for PTSD & chronic pain (CP) and CP groups)
• Therapeutic Mechanisms of Ketamine (review)
• Treatment response to low-dose ketamine infusion for treatment-resistant depression: A gene-based genome-wide association study (n=65, gene-based study that finds that some genes have predictive value on outcomes of ketamine for TRD)
• The acute antisuicidal effects of single-dose intravenous ketamine and intranasal esketamine in individuals with major depression and bipolar disorders: A systematic review and meta-analysis (“The findings suggest that single-dose IV ketamine/IN esketamine is associated with robust reductions in suicidal thoughts at 2-h, 4-h, and 24-h post-intervention“)
• Subanesthetic ketamine infusions for suicide ideation in patients with bipolar and unipolar treatment refractory depression (also see previous paper, lower SI scores up to 1 week later)
• Investigating the role of 5-HT2A and 5-HT2C receptor activation in the effects of psilocybin, DOI, and citalopram on marble burying in mice (in mice, possible implications for OCD research)
• Synergistic effects of MDMA and ethanol on behavior: Possible effects of ethanol on dopamine D ₂ -receptor-related signaling (“The combination of MDMA with ethanol enhanced their locomotor-increasing, rewarding, and discriminative stimulus effects without enhancing their effects on the release of dopamine from the nucleus accumbens in rodents“)
• Towards psychedelic apprenticeship: Developing a gentle touch for the mediation and validation of psychedelic-induced insights and revelations (model for working with/guiding psychedelic experiences)
• Ketamine reversed short-term memory impairment and depressive-like behavior in animal model of Parkinson’s disease (“ketamine reversed depressive-like behaviors and short-term memory impairment in rats with SNc bilateral lesions, indicating a promising profile for its use in PD patients“)
• Working memory associated with anti-suicidal ideation effect of repeated-dose intravenous ketamine in depressed patients (improvement in working memory (WM) as possible mechanism why ketamine reduces suicidal ideation (SI))
• Sleep improvement is associated with the antidepressant efficacy of repeated-dose ketamine and serum BDNF levels: a post-hoc analysis (n=127, better sleep led to better antidepressant effects of ketamine in those with MDD or BD)
• New psychoactive substances: a review and updates (review of new psychedelic(s) substances)