OPEN Foundation

P. Dolder

MDMA-induced changes in within-network connectivity contradict the specificity of these alterations for the effects of serotonergic hallucinogens

Abstract

It has been reported that serotonergic hallucinogens like lysergic acid diethylamide (LSD) induce decreases in functional connectivity within various resting-state networks. These alterations were seen as reflecting specific neuronal effects of hallucinogens and it was speculated that these shifts in connectivity underlie the characteristic subjective drug effects. In this study, we test the hypothesis that these alterations are not specific for hallucinogens but that they can be induced by monoaminergic stimulation using the non-hallucinogenic serotonin-norepinephrine-dopamine releasing agent 3,4-methylenedioxymethamphetamine (MDMA). In a randomized, placebo-controlled, double-blind, crossover design, 45 healthy participants underwent functional magnetic resonance imaging (fMRI) following oral administration of 125 mg MDMA. The networks under question were identified using independent component analysis (ICA) and were tested with regard to within-network connectivity. Results revealed decreased connectivity within two visual networks, the default mode network (DMN), and the sensorimotor network. These findings were almost identical to the results previously reported for hallucinogenic drugs. Therefore, our results suggest that monoaminergic substances can induce widespread changes in within-network connectivity in the absence of marked subjective drug effects. This contradicts the notion that these alterations can be regarded as specific for serotonergic hallucinogens. However, changes within the DMN might explain antidepressants effects of some of these substances.

Müller, F., Holze, F., Dolder, P., Ley, L., Vizeli, P., Soltermann, A., Liechti, M. E., & Borgwardt, S. (2021). MDMA-induced changes in within-network connectivity contradict the specificity of these alterations for the effects of serotonergic hallucinogens. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 46(3), 545–553. https://doi.org/10.1038/s41386-020-00906-2

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Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide Microdoses in Healthy Participants

Abstract

“Microdoses” of lysergic acid diethylamide (LSD) are used recreationally to enhance mood and cognition. Increasing interest has also been seen in developing LSD into a medication. Therefore, we performed a pharmacokinetic-pharmacodynamic study using very low doses of LSD. Single doses of LSD base (5, 10, and 20 µg) and placebo were administered in a double-blind, randomized, placebo-controlled crossover study in 23 healthy participants. Test days were separated by at least 5 days. Plasma levels of LSD and subjective effects were assessed up to 6 hours after administration. Pharmacokinetic parameters were determined using compartmental modeling. Concentration-subjective effect relationships were described using pharmacokinetic-pharmacodynamic modeling. Mean (95% confidence interval) maximal LSD concentrations were 151 pg/mL (127-181), 279 pg/mL (243-320), and 500 pg/mL (413-607) after 5, 10, and 20 µg LSD administration, respectively. Maximal concentrations were reached after 1.1 hours. The mean elimination half-life was 2.7 hours (1.5-6.2). The 5 µg dose of LSD elicited no significant acute subjective effects. The 10 µg dose of LSD significantly increased ratings of “under the influence” and “good drug effect” compared with placebo. These effects began an average of 1.1 hours after 10 µg LSD administration, peaked at 2.5 hours, and ended at 5.1 hours. The 20 µg dose of LSD significantly increased ratings of “under the influence,” “good drug effects,” and “bad drug effects.” LSD concentrations dose-proportionally increased at doses as low as 5-20 µg and decreased with a half-life of 3 hours. The threshold dose of LSD base for psychotropic effects was 10 µg.

Holze, F., Liechti, M. E., Hutten, N., Mason, N. L., Dolder, P. C., Theunissen, E. L., Duthaler, U., Feilding, A., Ramaekers, J. G., & Kuypers, K. (2021). Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide Microdoses in Healthy Participants. Clinical pharmacology and therapeutics, 109(3), 658–666. https://doi.org/10.1002/cpt.2057

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Mood and cognition after administration of low LSD doses in healthy volunteers: A placebo controlled dose-effect finding study

Abstract

There is a popular interest in microdosing with psychedelics such as LSD. This practice of using one-tenth of a full psychedelic dose according to a specific dosing schedule, anecdotally enhances mood and performance. Nonetheless, controlled research on the efficacy of microdosing is scarce. The main objective of the present dose-finding study was to determine the minimal dose of LSD needed to affect mood and cognition. A placebo-controlled within-subject study including 24 healthy participants, was conducted to assess the acute effects of three LSD doses (5, 10, and 20 mcg) on measures of cognition, mood, and subjective experience, up until 6 h after administration. Cognition and subjective experience were assessed using the Psychomotor Vigilance Task, Digit Symbol Substitution Test, Cognitive Control Task, Profile of Mood States, and 5-Dimensional Altered States of Consciousness rating scale. LSD showed positive effects in the majority of observations by increasing positive mood (20 mcg), friendliness (5, 20 mcg), arousal (5 mcg), and decreasing attentional lapses (5, 20 mcg). Negative effects manifested as an increase in confusion (20 mcg) and anxiety (5, 20 mcg). Psychedelic-induced changes in waking consciousness were also present (10, 20 mcg). Overall, the present study demonstrated selective, beneficial effects of low doses of LSD on mood and cognition in the majority of observations. The minimal LSD dose at which subjective and performance effects are notable is 5 mcg and the most apparent effects were visible after 20 mcg.

Hutten, N., Mason, N. L., Dolder, P. C., Theunissen, E. L., Holze, F., Liechti, M. E., Feilding, A., Ramaekers, J. G., & Kuypers, K. (2020). Mood and cognition after administration of low LSD doses in healthy volunteers: A placebo controlled dose-effect finding study. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 41, 81–91. https://doi.org/10.1016/j.euroneuro.2020.10.002

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Acute dose-dependent effects of lysergic acid diethylamide in a double-blind placebo-controlled study in healthy subjects

Abstract

Growing interest has been seen in using lysergic acid diethylamide (LSD) in psychiatric research and therapy. However, no modern studies have evaluated subjective and autonomic effects of different and pharmaceutically well-defined doses of LSD. We used a double-blind, randomized, placebo-controlled, crossover design in 16 healthy subjects (eight women, eight men) who underwent six 25 h sessions and received placebo, LSD (25, 50, 100, and 200 µg), and 200 µg LSD 1 h after administration of the serotonin 5-hydroxytryptamine-2A (5-HT2A) receptor antagonist ketanserin (40 mg). Test days were separated by at least 10 days. Outcome measures included self-rating scales that evaluated subjective effects, autonomic effects, adverse effects, plasma brain-derived neurotrophic factor levels, and pharmacokinetics up to 24 h. The pharmacokinetic-subjective response relationship was evaluated. LSD showed dose-proportional pharmacokinetics and first-order elimination and dose-dependently induced subjective responses starting at the 25 µg dose. A ceiling effect was observed for good drug effects at 100 µg. The 200 µg dose of LSD induced greater ego dissolution than the 100 µg dose and induced significant anxiety. The average duration of subjective effects increased from 6.7 to 11 h with increasing doses of 25-200 µg. LSD moderately increased blood pressure and heart rate. Ketanserin effectively prevented the response to 200 µg LSD. The LSD dose-response curve showed a ceiling effect for subjective good effects, and ego dissolution and anxiety increased further at a dose above 100 µg. These results may assist with dose finding for future LSD research. The full psychedelic effects of LSD are primarily mediated by serotonin 5-HT2A receptor activation.

Holze, F., Vizeli, P., Ley, L., Müller, F., Dolder, P., Stocker, M., Duthaler, U., Varghese, N., Eckert, A., Borgwardt, S., & Liechti, M. E. (2021). Acute dose-dependent effects of lysergic acid diethylamide in a double-blind placebo-controlled study in healthy subjects. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 46(3), 537–544. https://doi.org/10.1038/s41386-020-00883-6

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Low Doses of LSD Acutely Increase BDNF Blood Plasma Levels in Healthy Volunteers

Abstract

Despite preclinical evidence for psychedelic-induced neuroplasticity, confirmation in humans is grossly lacking. Given the increased interest in using low doses of psychedelics for psychiatric indications and the importance of neuroplasticity in the therapeutic response, this placebo-controlled within-subject study investigated the effect of single low doses of LSD (5, 10, and 20 μg) on circulating BDNF levels in healthy volunteers. Blood samples were collected every 2 h over 6 h, and BDNF levels were determined afterward in blood plasma using ELISA. The findings demonstrated an increase in BDNF blood plasma levels at 4 h (5 μg) and 6 h (5 and 20 μg) compared to that for the placebo. The finding that LSD acutely increases BDNF levels warrants studies in patient populations.

Hutten, N., Mason, N. L., Dolder, P. C., Theunissen, E. L., Holze, F., Liechti, M. E., Varghese, N., Eckert, A., Feilding, A., Ramaekers, J. G., & Kuypers, K. (2020). Low Doses of LSD Acutely Increase BDNF Blood Plasma Levels in Healthy Volunteers. ACS pharmacology & translational science, 4(2), 461–466. https://doi.org/10.1021/acsptsci.0c00099

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A low dose of lysergic acid diethylamide decreases pain perception in healthy volunteers

Abstract

Background: Lysergic acid diethylamide (LSD) is an ergot alkaloid derivative with psychedelic properties that has been implicated in the management of persistent pain. Clinical studies in the 1960s and 1970s have demonstrated profound analgesic effects of full doses of LSD in terminally ill patients, but this line of research evaporated after LSD was scheduled worldwide.

Aim: The present clinical study is the first to revisit the potential of LSD as an analgesic, and at dose levels which are not expected to produce profound mind-altering effects.

Methods: Twenty-four healthy volunteers received single doses of 5, 10 and 20 µg LSD as well as placebo on separate occasions. A Cold Pressor Test was administered at 1.5 and 5 h after treatment administration to assess pain tolerance to experimentally evoked pain. Ratings of dissociation and psychiatric symptoms as well as assessments of vital signs were included to monitor mental status as well as safety during treatments.

Results: LSD 20 µg significantly increased the time that participants were able to tolerate exposure to cold (3°C) water and decreased their subjective levels of experienced pain and unpleasantness. LSD elevated mean blood pressure within the normal range and slightly increased ratings of dissociation, anxiety and somatization.

Conclusion: The present study provides evidence of a protracted analgesic effect of LSD at a dose that is low enough to avoid a psychedelic experience. The present data warrant further research into the analgesic effects of low doses of LSD in patient populations.

Ramaekers, J. G., Hutten, N., Mason, N. L., Dolder, P., Theunissen, E. L., Holze, F., … & Kuypers, K. P. (2020). A low dose of lysergic acid diethylamide decreases pain perception in healthy volunteers. Journal of Psychopharmacology, 0269881120940937; 10.1177/0269881120940937
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Self-Rated Effectiveness of Microdosing With Psychedelics for Mental and Physical Health Problems Among Microdosers

Abstract

Background: There is a growing interest in the use of psychedelic substances for health related purposes, including symptom relief for disorders like anxiety, depression, and pain. Although the focus of recent clinical trials has been on high doses of these substances, anecdotal evidence suggests that low (micro) doses are also effective, and may be more suitable for certain conditions. Nonetheless, empirical evidence regarding the efficacy of microdosing with psychedelics for symptomatic relief is lacking. The present study aimed to investigate, by means of an online questionnaire, the self-rated effectiveness (SRE) of microdosing with psychedelics (MDP) for mental and physiological disorders compared to the conventional prescribed treatment and to regular doses of psychedelics. Methods: An online questionnaire was launched on several websites and fora between March and July 2018. Respondents who had consented, were 18 years of age or older, had experience with microdosing and were diagnosed with at least one mental or physiological disorder by a medical doctor or therapist (N = 410; 7.2%) were included in the analyses. Odds ratio were calculated to compare the SRE of MDP with conventional treatment, and regular psychedelic doses for mental and physiological diagnoses for each of the three effectiveness questions (“Did it work,” “Symptom disappear,” “Quality of life improved”). Results: Odds ratio showed that SRE of MDP was significantly higher compared to that of conventional treatments for both mental and physiological diagnoses; and that these effects were specific for ADHD/ADD and anxiety disorders. In contrast, SRE of MDP was lower compared to that of higher, regular psychedelic doses for mental disorders such as anxiety and depression, while for physiological disorders no difference was shown. Conclusion: This study demonstrates that SRE of MDP to alleviate symptoms of a range of mental or physiological diagnoses is higher compared to conventionally offered treatment options, and lower than regular (‘full’) psychedelic doses. Future RCTs in patient populations should objectively assess the effectivity claims of psychedelics, and whether these are dose related, disorder specific, and superior to conventional treatments.

Hutten, N. R., Mason, N. L., Dolder, P. C., & Kuypers, K. P. (2019). Self-rated effectiveness of microdosing with psychedelics for mental and physical health problems amongst microdosers. Frontiers in psychiatry10, 672. 10.3389/fpsyt.2019.00672

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Motives and side-effects of microdosing with psychedelics among users

Abstract

BACKGROUND:

Microdosing with psychedelics has gained considerable media attention where it is portrayed as a performance enhancer, especially popular on the work floor. While reports are in general positive, scientific evidence about potential negative effects is lacking aside from the prevalence and motives for use. The present study addressed this gap by surveying psychedelic users about their experience with microdosing including their dosing schedule, motivation, and potential experienced negative effects.

METHODS:

An online questionnaire was launched on several websites and fora between March and July 2018. Respondents who had consented, were 18 years of age or older, and had experience with microdosing were included in the analyses.

RESULTS:

In total, 1116 of the respondents were either currently microdosing (79.5%) or microdosed in the past (20.5%). Lysergic acid diethylamide (10 mcg) and psilocybin (0.5 g) were the most commonly used psychedelics with a microdosing frequency between 2 and 4 times per week. The majority of users, however, were oblivious about the consumed dose. Performance enhancement was the main motive to microdose (37%). The most reported negative effects were of psychological nature and occurred acutely while under the influence.

CONCLUSION:

In line with media reports and anecdotes, the majority of our respondents microdosed to enhance performance. Negative effects occurred mostly acutely after substance consumption. However, the main reason to have stopped microdosing was that it was not effective. Future experimental placebo-controlled studies are needed to test whether performance enhancement can be quantified and to assess potential negative effects after longer term microdosing.

Hutten, N. R., Mason, N. L., Dolder, P. C., & Kuypers, K. P. (2019). Motives and side-effects of microdosing with psychedelics among users. International Journal of Neuropsychopharmacology., 10.1093/ijnp/pyz029

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Altered network hub connectivity after acute LSD administration

Abstract

LSD is an ambiguous substance, said to mimic psychosis and to improve mental health in people suffering from anxiety and depression. Little is known about the neuronal correlates of altered states of consciousness induced by this substance. Limited previous studies indicated profound changes in functional connectivity of resting state networks after the administration of LSD. The current investigation attempts to replicate and extend those findings in an independent sample. In a double-blind, randomized, cross-over study, 100 μg LSD and placebo were orally administered to 20 healthy participants. Resting state brain activity was assessed by functional magnetic resonance imaging. Within-network and between-network connectivity measures of ten established resting state networks were compared between drug conditions. Complementary analysis were conducted using resting state networks as sources in seed-to-voxel analyses. Acute LSD administration significantly decreased functional connectivity within visual, sensorimotor and auditory networks and the default mode network. While between-network connectivity was widely increased and all investigated networks were affected to some extent, seed-to-voxel analyses consistently indicated increased connectivity between networks and subcortical (thalamus, striatum) and cortical (precuneus, anterior cingulate cortex) hub structures. These latter observations are consistent with findings on the importance of hubs in psychopathological states, especially in psychosis, and could underlay therapeutic effects of hallucinogens as proposed by a recent model.
Müller, F., Dolder, P. C., Schmidt, A., Liechti, M. E., & Borgwardt, S. (2018). Altered network hub connectivity after acute LSD administration. NeuroImage: Clinical. 10.1016/j.nicl.2018.03.005
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Acute effects of methylphenidate, modafinil and MDMA on negative emotion processing

Abstract

BACKGROUND:
Stimulants such as methylphenidate (MPH) and modafinil are frequently used as cognitive enhancers in healthy people, whereas 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is proposed to enhance mood and empathy in healthy subjects. However, comparative data on the effects of MPH and modafinil on negative emotions in healthy subjects have been widely missing. The aim of this study was to compare the acute effects of MPH and modafinil on the neural correlates of fearful face processing using MDMA as a positive control.
METHODS:
Using a double-blind within-subject placebo-controlled cross-over design, 60 mg MPH, 600 mg modafinil, and 125 mg MDMA were administrated to 22 healthy subjects, while performing an event-related fMRI task to assess brain activation in response to fearful faces. Negative mood states were assessed with the State-Trait Anxiety Inventory and subjective ratings.
RESULTS:
Relative to placebo, modafinil, but not MPH or MDMA, increased brain activation within a limbic-cortical-striatal-pallidal-thalamic circuit during fearful face processing. Modafinil but not MPH also increased amydgala responses to fearful faces compared with MDMA. Furthermore, activation in the middle and inferior frontal gyrus in response to fearful faces correlated positively with subjective feelings of fearfulness and depressiveness after modafinil administration.
CONCLUSIONS:
In spite of the cognitive enhancement effects of 600 mg modafinil in healthy people, potential adverse effects on emotion processing should be considered.
Schmidt, A., Müller, F., Dolder, P. C., Schmid, Y., Zanchi, D., Egloff, L., … & Borgwardt, S. (2017). Acute effects of methylphenidate, modafinil and MDMA on negative emotion processing. International Journal of Neuropsychopharmacology, pyx112. 10.1093/ijnp/pyx112
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