The HASHTAG Study is investigating whether the medicine semaglutide can help adults with cannabis use disorder (CUD) reduce their cannabis use. Participants will be randomly assigned to receive either semaglutide or a placebo. The first 50 participants will have functional brain scans (fMRI) to investigate how the brain responds to cannabis-related cues. The main outcome after 20 weeks is whether semaglutide reduces cannabis use compared to placebo. Changes in brain activity in response to cannabis cues will be explored as a secondary outcome.
This is a randomized (1:1), double-blind, placebo-controlled clinical study investigating whether semaglutide reduces cannabis use. Participants will receive weekly injections of semaglutide or placebo for 20 weeks, with the primary endpoint assessed at the end of treatment. A follow-up visit will occur at week 46. A total of 100 participants will be enrolled. Cannabis use and secondary outcomes will be measured at week 0, 6, 12, 20, and 46. Participants will also receive four sessions of supportive therapy. Randomization and blinding: Injections will be administered by staff who are not involved in any other study procedures to maintain the double-blind setup. Optional fMRI sub-study: Up to 50 eligible participants will undergo fMRI scans at baseline and week 20. Blood and urine samples will be collected for safety and secondary endpoints.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
100
semaglutide (Wegovy) once-weekly by subcutaneous injection, titrated to a maximum dose of 2.4 mg.
once-weekly by subcutaneous injection of saline (BD Posiflush)
Psychiatric Center Copenhagen, Frederiksberg Hospital
Frederiksberg, Denmark
RECRUITINGCannabis consumption
Total cannabis consumption (grams) over the last 28 days, measured using the Timeline Follow-back (TLFB) after 20 weeks of treatment and adjusted for baseline.
Time frame: From baseline to week 20.
Quantitative measure of cannabis metabolites
Change in plasma and urine concentrations of THC and its metabolites (11-hydroxy-delta 9-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH) levels)
Time frame: From baseline to week 20.
Cannabis consumption
Cannabis-free days over the past 28 days, assessed using self-reported TLFB.
Time frame: From baseline to week 20.
THC consumption
Total THC consumption, measured in standard THC units over 28 days after 20 weeks of treatment, assessed using TLFB and adjusted for baseline. Note: Total THC consumption is calculated based on grams used, method of administration, and average THC concentration from seized cannabis in DK.
Time frame: From baseline to week 20.
Severity of cannabis use
Change in Cannabis Use Disorders Identification Test - Revised (CUDIT-R) score. Minimum score = 0, maximum score = 32. A high score means a worse outcome.
Time frame: From baseline to week 20.
Cannabis problems
Change in Marijuana Problem Scale (MPS) score. Minimum score = 0, maximum score = 19. A high score means a worse outcome.
Time frame: From baseline to week 20.
Cannabis craving
Change in Marijuana Craving Questionnaire - Short Form (MCQ-SF) score. Minimum score = 12, maximum score = 84. A high score means a worse outcome.
Time frame: From baseline to week 20.
Depression symptoms
Change in Patient Health Questionnaire - 9 items (PHQ-9) total score. Minimum score = 0, maximum score = 27. A high score means a worse outcome.
Time frame: From baseline to week 20.
Subjective sleep quality
Change in Pittsburgh Sleep Quality Index (PSQI) global score. Minimum score = 0, maximum score = 21. A high score means a worse outcome.
Time frame: From baseline to week 20.
Severity of alcohol use
Change in Alcohol Use Disorder Identification Test (AUDIT) score. Minimum score = 0, maximum score =40. A high score means a worse outcome.
Time frame: From baseline to week 20.
Severity of drug use
Change in Drug Use Disorders Identification Test (DUDIT) score. Minimum score = 0, maximum score =44. A high score means a worse outcome.
Time frame: From baseline to week 20.
Drug use frequency
Change in drug use frequency measured using the drug use frequency section of the DUDIT-extended
Time frame: From baseline to week 20.
Severity of nicotine
Change in Fagerströms Test for Nicotine Dependence score. Minimum score = 0, maximum score =10. A high score means a worse outcome.
Time frame: From baseline to week 20.
Average Daily Cigarette Consumption
Change in mean cigarettes per day on average during the past week
Time frame: From baseline to week 20.
Changes in Quality of life
Change in World Health Organization Quality of Life - BREF (WHOQOL-BREF) domain scores. Scores are transformed to a 0 to 100 scale. Higher scores indicate better quality of life (better outcome).
Time frame: From baseline to week 20.
Body weight
Percent change in body weight (kilograms)
Time frame: From baseline to week 20.
Body fat and metabolic risk
Change in waist circumference (cm)
Time frame: From baseline to week 20.
Quantitative measure of nicotine intake
Change in Blood cotinine levels
Time frame: From baseline to week 20.
Cardiovascular parameters
Changes in Blood pressure (both systolic and diastolic)
Time frame: From baseline to week 20.
Cardiovascular parameters
Change in pulse
Time frame: From baseline to week 20.
Glycaemic parameters
Change in HbA1c
Time frame: From baseline to week 20.
Neural responses in brain regions associated with reward processing
Change in fMRI cue reactivity using a cannabis paradigm. Measures brain response to cannabis-related cues.
Time frame: From baseline to week 20.
Functional connectivity between NAc/septal regions and prefrontal cortex
Resting-state fMRI connectivity analysis
Time frame: From baseline to week 20.
Functional connectivity between NAc/septal regions and amygdala/insula
Resting-state fMRI connectivity analysis
Time frame: From baseline to week 20.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.