The goal of this clinical trial is to systematically categorize potential prohedonic effects of psilocybin in patients with anhedonia in depression. The main questions it aims to answer are: Primary Objectives 1. Systematically categorize prohedonic effects (antianhedonic effects in patients with anhedonia in depression, increase in well-being in all participants). 2. Test effects of psilocybin on brain network complexity measures during the hedonic experience using fMRI as a correlate for prohedonic (anti-anhedonic and well-being increasing) effects. 3. Elucidate relevance of the psychedelic experience to these effects (clinical, behavioral, and imaging) in a pharmacological challenge using the 5-HT2A/D2 antagonist risperidone and extensive characterization of the psychedelic experience. Secondary Objectives 4. Test the differential effects of the psychedelic experience on fMRI paradigms measuring symptoms shown to be altered in anhedonia, more specifically reward processing and sexual arousal. 5. Test the relevance of neuroplasticity (BDNF) and inflammatory parameters to anti-anhedonic, well-being promoting, and brain network dynamic complexity effects. 6. Test the effects of the psychedelic experience on BDNF and inflammatory parameters. Researchers will compare the effects of psilocybin in two separate sessions (one with psilocybin alone, one with co-administration of risperidone) in both patients with depression and anhedonia and healthy control participants. Participants will: * Take 25 mg of psilocybin p.o. in two sessions, in one of the two sessions they will take 1 mg risperidone p.o. before ingestion of psilocybin, to block psilocybin's acute psychedelic effects. * Undergo 3 MRI sessions, one before the first psilocybin session ('baseline') and one session each on the day after each respective psilocybin session. * Perform a variety of tasks during each fMRI session to asses the treatment's effects on anhedonia.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
85
Participants will recieve two doses of Psilocybin 25 mg to be taken orally over the course of the study.
30 minutes before administration of psilocybin in one of the sessions to inhibit acute psychedelic effects
Over the course of the study, participants will undergo three MRI measurement sessions. * M1 (baseline, before treatment) * M2 \& M3 (one day after each psilocybin session)
Medical University of Vienna, Department of Psychiatry and Psychotherapy, Division of General Psychiatry
Vienna, State of Vienna, Austria
RECRUITINGAesthetic task
This task is designed to evoke and probe the nature and extent of the aesthetic experience. Two sets of stimuli will be presented. Each set consists of 20 pieces of self-selected music with 10 pieces inducing highly hedonic experiences and 10 neutral pieces. After stimulus presentation, subjects will rate how aesthetically moving the experience was, whether they experienced chills, and what the valence of the experience was on a Likert scale.
Time frame: From enrolment until the second assessment session (up to 9 weeks after enrolment)
Monetary Incentive Delay (MID) Task
The MID task is established to evoke and assess reward and punishment, which are centrally involved in anhedonia. The task observes several stages of reward processing, i.e., reward prediction, anticipation and reward consumption. The aim of the paradigm is to maximize gain and avoid loss by fast reaction upon presentation of a target stimulus. A trial starts with the presentation of a cue, indicating the potential gain or loss (e.g., -1€, +3€). After a variable delay of for instance 3-5 seconds the target stimulus is shown, and subjects press a button as fast as possible. If the reaction is within a given time limit the amount is gained or loss avoided. Otherwise, the amount is not gained or lost. Each button press is followed by immediate feedback, showing the outcome and the accumulated amount of money.
Time frame: From enrolment until the last imaging session (up to 8 weeks after enrolment)
Sexual arousal task
This task has been implemented by our group to assess changes to sexual arousal, a central and burdensome, yet often understudied, component of anhedonia. During this task, subjects are presented images intended to be sexually arousing and are instructed to denote the extent to which they find the image arousing.
Time frame: From enrolment until the last imaging session (up to 8 weeks after enrolment)
Cognitive Flexibility Inventory (CFI)
The CFI is a 20-item self-report measure to assess two aspects of cognitive flexibility: the adaptive ability to perceive multiple alternative explanations for life occurrences and the ability to generate multiple alternative solutions to difficult situations, as well as having an internal locus of control, or the tendency to perceive difficult situations as somewhat controllable.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Intensity rating
A self-reported rating of the subjective intensity of the acute psychedelic experience will be collected after each medication session on a scale from 0 (not at all) to 4 (extreme).
Time frame: From enrolment until the second medication session (up to 8 weeks after enrolment)
Warwick-Edinburgh Mental Well-being Scale (WEMWBS)
The WEMWBS is a self-report scale which will be used to assess mental well-being over the course of study participation.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Beck-Depression-Inventory (BDI)
The BDI is a self-rated scale which is used to assess symptoms of depression.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Montgomery-Åsberg Depression Rating Scale (MADRS)
The MADRS is a observer-rated scale which is used to assess symptoms of depression.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Dimensional Anhedonia Rating Scale (DARS)
The DARS is a self-report scale that measures anhedonia across four domains on a five-point-likert scale.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Aesthetic Experiences Scale (AES)
The AES is a self-report scale which is used to assess aesthetic experiences in the form of 'aesthetic chills', the response of goose bumps and shivers in response to the arts.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Temporal Experience of Pleasure Scale (TEPS)
The TEPS is a self-rating scale which is used to assess the experience of anticipatory and consummatory experiences of pleasure.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Barcelona Music Reward Questionnaire (BMRQ)
The BMRQ is a psychometric scale designed to assess different factors underlying the experience of music reward, as measured through 20 items on a 5-point Likert scale.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
5-Dimensional Altered States of Consciousness Rating (5D-ASC)
Properties of the psychedelic experience as assessed via the 5D-ASC, a a 94-item self-report scale that assesses the participants' alterations from normal waking Consciousness.
Time frame: From enrolment until the second medication session (up to 8 weeks after enrolment)
Mystical Experience Questionnaire (MEQ30)
Properties of the psychedelic experience as assessed via the MEQ30, a 30 point self-rated scale, which is used to measure the intensity of common aspects of a psychedelic experience (divided into mystical, positive mood, transendence of time and space, and ineffability).
Time frame: From enrolment until the second medication session (up to 8 weeks after enrolment)
Challenging Experience Questionnaire (CEQ)
Properties of the psychedelic experience as assessed via the Challenging Experience Questionnaire (CEQ), an instrument designed to measure challenging psychological experiences associated with the acute effects of psychedelics.
Time frame: From enrolment until the second medication session (up to 8 weeks after enrolment)
Connor-Davidson Resilience Scale (CD-RISC)
The CD-RISC is a self-rating scale which is used to assess changes in study participants' resilience over the course of their participation.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Cytokine panel
Changes in proinflammaotry cytokines, suchz as interleukin 6 and tumor necrosis factor alpha, which have been associated with depression and anhedonia, assessed via Legendplex cytokine panel
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Brain-derived neurotrophic factor (BDNF) concentration
Changes in blood markers which have been associated with depression and anhedonia, assessed via BDNF concentration.
Time frame: From enrolment until the last follow-up session (expected at about 12 weeks after enrolment)
Neural activity
Neural activity during MID and sexual arousal task, assessed via fMRI measurement.
Time frame: Over the course of the three MRI sessions (3-14 days after enrolment, 1 day after the first medication session, 6 weeks after the second measurement)
Brain network dynamic complexity
Brain complexity measures during the hedonic experience assessed with fMRI, as assesed via integrated information decomposition and BOLD variability
Time frame: Over the course of the three MRI sessions (3-14 days after enrolment, 1 day after the first medication session, 6 weeks after the second measurement)
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