A Phase 3 interventional study of Psilocybin (high dose) and Psilocybin (low dose) in Alcohol Use Disorder, Depressive Sympotoms and Psilocybin, sponsored by Centre Hospitalier Universitaire de Nīmes. Recruiting at 8 sites in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-01.
Sponsored by Centre Hospitalier Universitaire de Nīmes · Phase 3, Interventional, and Treatment
Up to 40% of individuals with alcohol use disorder (AUD) experience depression, which increases the risk of early relapse. Depression can cause relapse to occur 3 times faster in individuals with AUD who experience depressive symptoms at discharge. No treatments have been approved for individuals with both AUD and depression. Psilocybin, a psychedelic, shows promising results in treating both depression and addiction. It may be particularly effective for preventing relapse in people with AUD who also have depressive symptoms after detoxification, offering quicker action than traditional antidepressants.
The Psilocybin Alcohol Depression (PAD) pilot study, launched in February 2024, has provided critical insights for avoiding methodological flaws and demonstrated that psilocybin-assisted psychotherapy (PAP) is both feasible and acceptable. Preliminary efficacy analyses were conducted: at 12 weeks, the 25 mg group showed significantly greater reductions in drinking days (p = 0.038) and craving frequency (p = 0.045). Relapse rates were 35% in the 25 mg group and 50% in the control group (HR = 0.52 [0.16-1.65]). In the ERPPAD trial, the study authors will compare high-dose PAP with low-dose PAP in preventing relapse in individuals with AUD and depressive symptoms. The hypothesis is that high-dose PAP will be more effective than low-dose in preventing relapse over 6 months.
1,606 studies on the registry are indexed under Alcoholism; 329 are open to participants now.
This study's planned enrollment of 172 is above the median of 87 across 1,371 interventional studies indexed under Alcoholism.
Browse Alcoholism studies →Centre Hospitalier Universitaire de Nīmes is the lead sponsor of 587 studies on the registry; 96 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
2 administrations of high-dose psilocybin (25 mg) 3 weeks apart
Drug: Psilocybin (high dose)
2 administrations of low-dose psilocybin (3 mg) 3 weeks apart
Drug: Psilocybin (low dose)
2 administrations of high-dose psilocybin (25 mg) 3 weeks apart
2 administrations of low-dose psilocybin (3 mg) 3 weeks apart
Incidence of relapse between groups
Relapse Yes/no, where relapse is defined as the 1st heavy drinking day, assessed using the Timeline Follow-Back (TLFB) method
Time frame: Month 6
Time to relapse between groups
Days until relapse, where relapse is defined as the 1st heavy drinking day, assessed using the Timeline Follow-Back (TLFB) method
Time frame: Month 6
Change in relapse rate between groups
Assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in rate of heavy drinking days between groups
Percent; Assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in total alcohol consumption between groups
Grams, assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in number of drinking days between groups
Days, assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in craving between groups
Assessed using the Craving Experience Questionnaire (CEQ), measuring strength and frequency of craving with a score ranging from 0 to 110, whereby a higher score denotes more craving.
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in alcohol-related quality of life between groups
Alcohol Quality of Life Scale- brief, a 7-item questionnaire assessing the negative impact of alcohol across 7 dimensions: social relationships, activities, living conditions, self-care, negative emotions, sleep, and loss of control.
Time frame: At weeks 3, 15, 21, 27 compared to baseline
Change in anxiety between groups
Beck Anxiety Inventory (BAI)
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in emotional dysregulation between groups
Difficulties in Emotion Regulation Scale (DERS), a 36-item questionnaire
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in rejection sensitivity between groups
Adult Rejection Sensitivity Questionnaire (A-RSQ)
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Change in post-Traumatic Stress Disorder between groups
Post-Traumatic Stress Disorder Checklist for DSM-5 (PCL-5), where a score of 44 is highly sensitive to diagnose PTSD
Time frame: At weeks 3, 9, 15, 21, 27 compared to baseline
Visual Perspective task (VPT)
This task allows calculation of the egocentric bias index, the altercentric bias index and the egocentric egocentric bias
Time frame: Day 0
Visual Perspective task (VPT)
This task allows calculation of the egocentric bias index, the altercentric bias index and the egocentric egocentric bias
Time frame: Week 3
Visual Perspective task (VPT) for participants opting for a third dose
This task allows calculation of the egocentric bias index, the altercentric bias index and the egocentric egocentric bias
Time frame: Week 28
Request for a 3rd dose of psilocybin between groups
Yes/no
Time frame: Week 27
Reason for 3rd dose request
Relapse in AUD/ risk of relapse in AUD/low self-efficacy/ relapse in depression/ personal development/ other
Time frame: Week 27
Administration of 3rd dose
Yes/no
Time frame: Week 28
Relapse rate in relapsers between groups
Assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Rate of heavy drinking days in relapsers between groups
Percent; Assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Total alcohol consumption in relapsers between groups
Grams, assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in number of drinking days in relapsers between groups
Days, assessed using the Timeline Follow-Back (TLFB) method
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in craving in relapsers between groups
Assessed using the Craving Experience Questionnaire (CEQ), measuring strength and frequency of craving with a score ranging from 0 to 110, whereby a higher score denotes more craving.
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in alcohol-related quality of life in relapsers between groups
Alcohol Quality of Life Scale- brief, a 7-item questionnaire assessing the negative impact of alcohol across 7 dimensions: social relationships, activities, living conditions, self-care, negative emotions, sleep, and loss of control.
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in depressive symptoms in relapsers between groups
Beck Depression Inventory-II (BDI-II). The total score is the sum of the 21 item scores, ranging from 0 to 39. Higher scores indicate greater severity of depression.
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in anxiety in relapsers between groups
Beck Anxiety Inventory (BAI)
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in emotional dysregulation in relapsers between groups
Difficulties in Emotion Regulation Scale (DERS), a 36-item questionnaire
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in rejection sensitivity in relapsers between groups
Adult Rejection Sensitivity Questionnaire (A-RSQ)
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Change in post-Traumatic Stress Disorder between groups
Post-Traumatic Stress Disorder Checklist for DSM-5 (PCL-5), where a score of 44 is highly sensitive to diagnose PTSD
Time frame: At weeks 33, 39, 45, 51 compared to week 27
Adverse Childhood Experiences
The Adverse Childhood Experiences (ACE) Questionnaire
Time frame: Day 0
Attachment style
The Relationship Scale Questionnaire (RSQ) for attachment style (secure, fearful, preoccupied, dismissing)
Time frame: Day 0
Severity of aocohol use disorder
The Clinical Global Impression- Severity (CGI-S)
Time frame: Day 0
Cognitive impairments
Montreal Cognitive Assessment (MoCA)
Time frame: Day 0
Features of the psychedelic experience
Acceptance/Avoidance Promoting Experience Questionnaire (APEQ)
Time frame: Prior to integration session in Week 0
Features of the psychedelic experience
Acceptance/Avoidance Promoting Experience Questionnaire (APEQ)
Time frame: Prior to integration session in Week 3
Features of the psychedelic experience
Acceptance/Avoidance Promoting Experience Questionnaire (APEQ)
Time frame: Prior to integration session in Week 28 if third dose
Age
years
Time frame: Day 0
Sex
Time frame: Day 0
Currently under antidepressant at the inclusion
Yes/no
Time frame: Day 0
Diagnosed with ADHD
Yes/no
Time frame: Day 0
In menstruating participants, point of the menstruation cycle at psilocybin administration
Time frame: Dosing session in week 0
In menstruating participants, point of the menstruation cycle at psilocybin administration
Time frame: Dosing session in week 3
In menstruating participants, point of the menstruation cycle at psilocybin administration
Time frame: Dosing session in week 28 if third dose
Safety and tolerance of psilocybin
List of adverse events
Time frame: End of study, week 51
Change in gamma-glutamyl transferase (GGT) between groups and subgroups
fL
Time frame: At week 28 compared to baseline
Change in carbohydrate-deficient transferrin (CDT) between groups and subgroups
U/L
Time frame: At week 28 compared to baseline
Change in mean corpuscular volume (MCV) between groups and subgroups
Percentage
Time frame: At week 28 compared to baseline
Guess the group
Two-item questionnaire developed from the EPIsoDE framework
Time frame: After dosing session Week 0
Guess the group
Two-item questionnaire developed from the EPIsoDE framework
Time frame: After dosing session Week 3
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Centre Hospitalier Universitaire de Nīmes