Alcohol AddictionPhase 2ICONICplusNCT06845124
A Trial to Investigate the Effects of Cannabidiol Plus Naltrexone on Alcohol Craving in Patients With Alcohol Dependence
A Phase 2 study testing Cannabidiol capsules and Naltrexone (drug) in people with Alcohol Addiction and Alcoholism, run by Central Institute of Mental Health, Mannheim at 2 sites in Germany.
Trial summary
Alcohol addiction (AD) is a chronic relapsing disorder with currently limited pharmacological treatment options. Alcohol craving, a hallmark symptom of AD that drives relapse in patients, is only insufficiently treated by existing medication. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Alcohol Addiction, Alcoholism
- What is being tested?
- Cannabidiol capsules and Naltrexone (drug)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 150 participants
- Where
- 2 sitesGermany
- Study dates
- 22 Jul 2025to 30 Sep 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age between 18 and 70 years
- Patients meeting the diagnosis of an alcohol dependence according to the ICD-10
- Patients reporting alcohol craving as symptom of AD according to the ICD10 symptom definition
- Ability of subject to understand character and individual consequences of the clinical trial
- Written informed consent (must be available before enrollment in the study)
- Consent to random assignment
- For women with childbearing potential (WOCBP) and males with partners with CBP, use of a highly effective birth control method until one month after last IMP administration (see Appendix 1) and negative pregnancy test
Who cannot join
- Current psychotic or bipolar disorder or current severe depressive episode with suicidal ideations
- Current treatment with any of the following substances: Any investigational medicinal product, Opioid-containing Analgesics, Anti-obesity drugs, Anticonvulsants, Opioid-containing Antidiarrheal Agents, Antineoplastics, Antipsychotics (exception: episodic use of melperone, prothipendyl, pipamperone, promethazine and quetiapine are allowed), Antidepressants (exception: allowed, when being taken in stable dose for a minimum of 14 days prior to enrolment and/or doxepine in low doses [max. 75mg daily]), Opioid-containing Cough/cold agents, Systemical Steroids, Other anti-craving (e.g. Acamprosate) or aversive medication (e.g. disulfiram), THC- or CBD-containing medication, Antiretroviral medication (e.g., Efavirenz), Xanthines (e.g., Theophylline), General anesthetics (e.g., propofol), Hypericum perforatum, Antibiotics (e.g., Rifampin, Clarithromycin, Erythromycin)
- Positive drug screening (amphetamines/ecstasy, opiates, cocaine, barbiturates)
- Pregnancy, lactation or breastfeeding
- Current severe somatic comorbidities: severe liver cirrhosis [CHILD B or C] or epilepsy determined by medical history
- Patients with elevated transaminase levels (AST or ALT) above three times the upper limit normal (ULN) value with elevated bilirubin levels above twice the ULN value
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- History of hypersensitivity to the investigational medicinal product CBD and/or Naltrexone (trade names: Adepend, Naltrexon-Hcl neuraxpharm, Naltrexonhydrochlorid Accord) or to any drug with similar chemical structure or to any excipient present in the pharmaceutical form of the investigational medicinal product CBD and/or Naltrexone
- Participation in other clinical trials or observation period of competing clinical trials, respectively.
- Acute suicidal tendency or acute endangerment of self and others
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Germany2 sites, 2 recruiting
- Recruiting
Central Institute of Mental Health
Mannheim, 68159
Patrick Bach, Prof. Dr. Dr., +496211703, patrick.bach@zi-mannheim.de
Sina Vetter, M.Sc., +496211703, Sina.Vetter@zi-mannheim.de
- Not yet recruiting
Psychiatric Centre North Baden (PZN)
Wiesloch, Baden-Wurttemberg, 69168
Tobias Link, Dr., +49 6222 55-2790, sekretariat.sucht@pzn-wiesloch.de
Tobias Link, Dr.
About this study
Official title: ICONICplus - Randomized, Double-blind, Placebo-controlled Trial to Investigate the Effects of Cannabidiol Plus Naltrexone on Cue-Induced Alcohol Craving in Alcohol Dependence
Alcohol addiction (AD) is a chronic relapsing disorder with currently limited pharmacological treatment options. Alcohol craving, a hallmark symptom of AD that drives relapse in patients, is only insufficiently treated by existing medication. One promising new compound for the treatment of alcohol craving in AD is Cannabidiol (CBD), which showed beneficial effects on alcohol craving in preliminary clinical studies. Additionally, CBD seems to be a particularly promising candidate for enhancing the effects of established medication, specifically Naltrexone (NTX), an opioid-antagonist, which is approved for AD treatment, due to the synergistic effects of the combination of Cannabidiol plus Naltrexone on alcohol consumption that were shown by preclinical studies. The proposed three-armed, 1:1:1 randomized, double-blind, placebo-controlled parallel group, multicentric phase II trial seeks to test the putative synergistic effects of combined CBD (800mg) + oral NTX (50mg) against CBD (1200mg) + oral NTX (50mg) against Placebo + oral NTX (50mg) on alcohol craving (primary outcome) in male and female patients with AD that suffer from high alcohol craving. The trial seeks to test the effects of the innovative combination of CBD plus NTX against Placebo plus NTX on alcohol craving over a 14-day treatment period, which is embedded in a standardized addiction treatment program according to current treatment guidelines, in order to estimate the added value of treatment with CBD on alcohol craving. Quality of life and neurobiological and biochemical markers for craving will serve as secondary outcomes, because they show strong associations to treatment outcome and relapse risk. Collection and analysis of follow-up data (28 days, 42 days, 105 days, 196 days) will be performed to determine whether treatment effects relate to patient outcome.
- Conditions
- Alcohol Addiction, Alcoholism
- Being tested
- Cannabidiol capsules, Naltrexone (drug), Placebo
- Medical subject headings
- Alcoholism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cannabidiol capsulesDrug
800mg (trial arm 1) or 1200mg (trial arm 2) Cannabidiol capsules will be administered daily over the course of 14 days.
Naltrexone (drug)Drug
All participants will receive 50mg Naltrexone daily as oral tablet throughout the study.
PlaceboDrug
Placebo capsules matching the cannabidiol capsules will be administered daily.
| Study group | Role | What they receive |
|---|---|---|
| Cannabidiol (800mg) + Naltrexone | Experimental | All patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the experimental group of trial arm 1, patients will receive a dose of 800mg Cannabidiol (CBD) daily over the course of 14 days during in-patient treatment. Receives: Drug: Cannabidiol capsules; Drug: Naltrexone (drug) |
| Cannabidiol (1200mg) + Naltrexone | Experimental | All patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the experimental group of trial arm 2, patients will receive a dose of 1200mg Cannabidiol (CBD) daily over the course of 14 days during in-patient treatment. Receives: Drug: Cannabidiol capsules; Drug: Naltrexone (drug) |
| Placebo + Naltrexone | Active comparator | All patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the comparator group of trial arm 3, patients will receive placebo capsules daily over the course of 14 days during in-patient treatment. Receives: Drug: Naltrexone (drug); Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Obsessive Compulsive Drinking Scale (OCDS-G)
The alcohol craving will be assessed at separate time points before and after Cannabidiol administration using the Obsessive Compulsive Drinking Scale.
The Obsessive Compulsive Drinking Scale consists of 14 items, each rated on a 5-point Likert scale (0-4), resulting in scores from 0 to 40, with higher scores indicating higher craving.
Measured: The difference of alcohol craving between baseline (visit 2) and 14 days after the first treatment visit (visit 5) will serve as primary endpoint.
Secondary outcomes (18)
Obsessive Compulsive Drinking Scale (OCDS-G)
The alcohol craving will be assessed at separate time points before and after Cannabidiol administration using the Obsessive Compulsive Drinking Scale.
The Obsessive Compulsive Drinking Scale consists of 14 items, each rated on a 5-point Likert scale (0-4), resulting in scores from 0 to 40, with higher scores indicating higher craving.
Measured: Differences from baseline (visit 2, day -2) of Obsessive Compulsive Drinking Scale craving scores to visits 4 (day 7, i.e., 7 days after the first treatment visit) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Subjective quality of life index
Quality of life will be assessed using the World Health Organization Quality of life questionnaire (WHO-QOL-BREF) scores at separate time points before and after Cannabidiol administration. The World Health Organization Quality of life questionnaire is an instrument that can assess patients' global health status independently of disease across 4 health domains and consists of 26 items rated on a 5-point Likert scale (1-5). To calculate the score, items 3, 4, 26 have to be inverted. Scores for each domain (Physical Health, Psychological Health, Social Relationships, Environment) are calculated, that range from 4 to 20. Higher scores indicate better quality of life, with the overall score reflecting a person's general well-being.
Measured: Differences from baseline (visit 2, day -2) of Quality of life (WHO-QOL-BREF scores) to end of treatment (visit 5, day 14) and follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196).
Beck Depression Inventory (BDI-II)
The depressive symptoms will be assessed at separate time points before and after Cannabidiol administration using the Beck Depression Inventory (BDI-II). The Beck Depression Inventory (BDI-II) is a 21-item self-rating inventory that measures characteristic attitudes and symptoms of depression. Each Item is rated on a 4-point Likert scale (0-3). The total score ranges from 0 to 63, with higher scores indicating more severe depressive symptoms.
Measured: Difference from baseline (visit 2, day -2) of depressive symptoms to end of treatment (visit 5, day 14)
State Trait Anxiety Inventory (STAI)
The state and trait anxiety will be assessed at separate time points before and after Cannabidiol administration using the State Trait Anxiety Inventory. The State Trait Anxiety Inventory (STAI) is a 20-item self-report questionnaire that assesses state anxiety and trait anxiety via two subscales: the State Anxiety Scale (STAI-S) and the Trait Anxiety Scale (STAI-T), each consisting of 20 items. Each item is rated on a 4-point Likert scale (1-4). A sumscore has to be calculated for each subscale, ranging from 20 to 80 each, with higher scores indicating higher levels of anxiety.
Measured: Difference from baseline (visit 2, day -2) of depressive symptoms to end of treatment (visit 5, day 14)
Patient reported outcomes (PRO)
The patient reported outcomes will be assessed at separate time points before and after Cannabidiol administration using a set of items assessing effects of the treatment as well as treatment burden on a five-point Likert scale (0 to 4) with higher values indicating more positive effects.
Measured: On visit 3 (day 1 of treatment), visit 4 (day 7 of treatment), visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
CBD plasma levels
The CBD plasma levels will be determined at separate time points before and after Cannabidiol administration to detect effects of active intervention on blood plasma levels. (Only participants enrolled at CIMH study site).
Measured: On visit 3 (day 1 of treatment) and visit 5 (day 14, end of treatment)
Adverse Events (AEs) and Serious Adverse Events (SAEs)
Rate of adverse events and serious adverse events.
Measured: On visit 3 (day 1 of treatment), visit 4 (day 7 of treatment), visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Time to relapse
Time from baseline (visit 2, day -2) to relapse to alcohol use (i.e. any alcohol use) (in days), assessed using the Form-90 semi-structured interview (Timeline Follow Back).
Measured: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Cumulative alcohol consumption during the follow-up period
Cumulative alcohol consumption (in grams alcohol) during the follow-up period of 182 days (+/- 7 days), assessed using the Form-90 semi-structured interview (Timeline Follow Back).
Measured: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Percent heavy drinking days during the follow-up period
Percent heavy drinking days during the follow-up period of 182 days (+/- 7 days), assessed using the Form-90 semi-structured interview (Timeline Follow Back).
Measured: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Average weekly alcohol consumption during the follow-up period
Average weekly alcohol consumption assessed via smartphone-based e-diary every 7 days during the follow-up period of 182 days (+/- 7 days) (optional, only for patients that agree to use the study-specific app).
Measured: Every 7 days during the follow-up period of 182 days (+/- 7 days), starting after visit 5, i.e., end of treatment (day 14) and continuing until visit 9, i.e., end of follow up (day 196)
Maximum weekly craving during the follow-up period
Maximum weekly craving assessed via smartphone-based e-diary every 7 days during the follow-up period of 182 days (+/- 7 days) (optional, only for patients that agree to use the study-specific app).
Measured: Every 7 days during the follow-up period of 182 days (+/- 7 days), starting after visit 5, i.e., end of treatment (day 14) and continuing until visit 9, i.e., end of follow up (day 196)
Neural Brain Activation during functional magnetic resonance imaging
Differences from baseline of neural brain activation to visit 5, measured using the blood oxygenated level dependent (BOLD) response, during presentation of alcohol cues, during the presentation of natural reward cues, during inhibition of motor responses, during presentation of emotional faces and neutral shapes and functional connectivity during resting state (only for patients enrolled at CIMH study site).
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Alcohol Craving during functional magnetic resonance imaging
Differences from baseline of alcohol craving (visual analogue scale) during the functional magnetic resonance imaging (fMRI) to visit 5 (only for patients enrolled at CIMH study site).
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Response Times during functional magnetic resonance imaging
Differences in response times (i.e., time taken to respond) during functional magnetic resonance imaging (fMRI) from baseline to visit 5 (only for patients enrolled at CIMH study site).
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Rates of Errors during functional magnetic resonance imaging
Differences in rates of errors during functional magnetic resonance imaging (fMRI) from baseline to visit 5 (only for patients enrolled at CIMH study site)
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Rates of Correct Responses during functional magnetic resonance imaging
Differences in rates of correct responses during functional magnetic resonance imaging (fMRI) from baseline to visit 5 (only for patients enrolled at CIMH study site)
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Omission Rates during functional magnetic resonance imaging
Differences in omission rates (i.e., rate of failure to respond when a response is expected) during functional magnetic resonance imaging (fMRI) from baseline to visit 5 (only for patients enrolled at CIMH study site)
Measured: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2025
- Study start22 Jul 2025
- Primary completion1 Apr 2028 (estimated)
- Study completion30 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Alcohol AddictionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Central Institute of Mental Health, Mannheim
- Sponsor type
- University, hospital or other
- Collaborators
- Heidelberg University, Heinrich-Heine University, Duesseldorf, German Federal Ministry of Education and Research
- Responsible party
- Sponsor
- Investigators
- Patrick Bach, Prof. Dr. Dr., Study director, Central Institute of Mental Health, Mannheim
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06845124
- Sponsor's protocol ID
- CIMH ICONICplus 25
- Other IDs
- 2024-518164-12-00
- Acronym
- ICONICplus
- Status last verified
- Jan 2026
- First submitted
- 13 Feb 2025
- Last updated
- 3 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual de-identified data will be shared, specifically individual participant data that underlie the results of the trial (i.e. primary outcome data \[OCDS-G scores\]) will be made available with a respective data dictionary. Secondary Outcome data (e.g. fMRI data) will be made available on aggregated group level (e.g. for the purpose of meta-analyses). Related documents, specifically the study protocol, statistical analysis plan and analytic code will be shared in open-access online repositories. Aggregated data will be made available to publicly accessible repositories (Neurosynth.org), e.g. for the purpose of meta-analyses.
Publications
Vetter S, Weinberg J, Thomas BC, Kirchner M, Thalmann P, Klose C, Pfisterer M, Kolsch T, Oesterle S, Vollstaedt-Klein S, Koopmann A, Lenz B, Kiefer F, Link T, Bach P. Investigation of the combined effects of cannabidiol plus naltrexone on alcohol craving in alcohol dependence: study protocol of a phase II randomised, double-blind, placebo-controlled, parallel-group trial - ICONICplus Trial. BMJ Open. 2025 Aug 12;15(8):e106348. doi: 10.1136/bmjopen-2025-106348.
PubMed 40803733
Study at a glance
From the registry record, last updated by the sponsor on 3 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ICONICplus - Randomized, Double-blind, Placebo-controlled Trial to Investigate the Effects of Cannabidiol Plus Naltrexone on Cue-Induced Alcohol Craving in Alcohol Dependence
- ClinicalTrials.gov ID
- NCT06845124
- Acronym / sponsor ID
- ICONICplus / CIMH ICONICplus 25
- Conditions
- Alcohol Addiction, Alcoholism
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Central Institute of Mental Health, MannheimUniversity, hospital or other
- Collaborators
- Heidelberg University, Heinrich-Heine University, Duesseldorf, German Federal Ministry of Education and Research
- Study start
- 22 Jul 2025 (actual)
- Primary completion
- 1 Apr 2028 (estimated)
- Study completion
- 30 Sep 2028 (estimated)
- First posted
- 25 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Alcohol addiction (AD) is a chronic relapsing disorder with currently limited pharmacological treatment options. Alcohol craving, a hallmark symptom of AD that drives relapse in patients, is only insufficiently treated by existing medication. One promising new compound for the treatment of alcohol craving in AD is Cannabidiol (CBD), which showed beneficial effects on alcohol craving in preliminary clinical studies. Additionally, CBD seems to be a particularly promising candidate for enhancing the effects of established medication, specifically Naltrexone (NTX), an opioid-antagonist, which is approved for AD treatment, due to the synergistic effects of the combination of Cannabidiol plus Naltrexone on alcohol consumption that were shown by preclinical studies. The proposed three-armed, 1:1:1 randomized, double-blind, placebo-controlled parallel group, multicentric phase II trial seeks to test the putative synergistic effects of combined CBD (800mg) + oral NTX (50mg) against CBD (1200mg) + oral NTX (50mg) against Placebo + oral NTX (50mg) on alcohol craving (primary outcome) in male and female patients with AD that suffer from high alcohol craving. The trial seeks to test the effects of the innovative combination of CBD plus NTX against Placebo plus NTX on alcohol craving over a 14-day treatment period, which is embedded in a standardized addiction treatment program according to current treatment guidelines, in order to estimate the added value of treatment with CBD on alcohol craving. Quality of life and neurobiological and biochemical markers for craving will serve as secondary outcomes, because they show strong associations to treatment outcome and relapse risk. Collection and analysis of follow-up data (28 days, 42 days, 105 days, 196 days) will be performed to determine whether treatment effects relate to patient outcome.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Cannabidiol (800mg) + Naltrexone | Experimental | Drug: Cannabidiol capsules, Drug: Naltrexone (drug)All patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the experimental group of trial arm 1, patients will receive a dose of 800mg Cannabidiol (CBD) daily over the course of 14 days during in-patient treatment. |
| Cannabidiol (1200mg) + Naltrexone | Experimental | Drug: Cannabidiol capsules, Drug: Naltrexone (drug)All patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the experimental group of trial arm 2, patients will receive a dose of 1200mg Cannabidiol (CBD) daily over the course of 14 days during in-patient treatment. |
| Placebo + Naltrexone | Active comparator | Drug: Naltrexone (drug), Drug: PlaceboAll patients will receive 50mg Naltrexone daily (NTX, oral tablet) in the course of standard in-patient treatment. In the comparator group of trial arm 3, patients will receive placebo capsules daily over the course of 14 days during in-patient treatment. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Age between 18 and 70 years
- Patients meeting the diagnosis of an alcohol dependence according to the ICD-10
- Patients reporting alcohol craving as symptom of AD according to the ICD10 symptom definition
- Ability of subject to understand character and individual consequences of the clinical trial
- Written informed consent (must be available before enrollment in the study)
Key exclusion criteria (9 listed)
- Current psychotic or bipolar disorder or current severe depressive episode with suicidal ideations
- Current treatment with any of the following substances: Any investigational medicinal product, Opioid-containing Analgesics, Anti-obesity drugs, Anticonvulsants, Opioid-containing Antidiarrheal Agents, Antineoplastics, Antipsychotics (exception: episodic use of melperone, prothipendyl, pipamperone, promethazine and quetiapine are allowed), Antidepressants (exception: allowed, when being taken in stable dose for a minimum of 14 days prior to enrolment and/or doxepine in low doses [max. 75mg daily]), Opioid-containing Cough/cold agents, Systemical Steroids, Other anti-craving (e.g. Acamprosate) or aversive medication (e.g. disulfiram), THC- or CBD-containing medication, Antiretroviral medication (e.g., Efavirenz), Xanthines (e.g., Theophylline), General anesthetics (e.g., propofol), Hypericum perforatum, Antibiotics (e.g., Rifampin, Clarithromycin, Erythromycin)
- Positive drug screening (amphetamines/ecstasy, opiates, cocaine, barbiturates)
- Pregnancy, lactation or breastfeeding
- Current severe somatic comorbidities: severe liver cirrhosis [CHILD B or C] or epilepsy determined by medical history
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cannabidiol capsules800mg (trial arm 1) or 1200mg (trial arm 2) Cannabidiol capsules will be administered daily over the course of 14 days. | Drug | Cannabidiol (1200mg) + Naltrexone, Cannabidiol (800mg) + Naltrexone |
| Naltrexone (drug)All participants will receive 50mg Naltrexone daily as oral tablet throughout the study. | Drug | Cannabidiol (1200mg) + Naltrexone, Cannabidiol (800mg) + Naltrexone, Placebo + Naltrexone |
| PlaceboPlacebo capsules matching the cannabidiol capsules will be administered daily. | Drug | Placebo + Naltrexone |
Primary outcome
Obsessive Compulsive Drinking Scale (OCDS-G)
Time frame: The difference of alcohol craving between baseline (visit 2) and 14 days after the first treatment visit (visit 5) will serve as primary endpoint.
The alcohol craving will be assessed at separate time points before and after Cannabidiol administration using the Obsessive Compulsive Drinking Scale. The Obsessive Compulsive Drinking Scale consists of 14 items, each rated on a 5-point Likert scale (0-4), resulting in scores from 0 to 40, with higher scores indicating higher craving.
18 secondary outcomes
Obsessive Compulsive Drinking Scale (OCDS-G)
Time frame: Differences from baseline (visit 2, day -2) of Obsessive Compulsive Drinking Scale craving scores to visits 4 (day 7, i.e., 7 days after the first treatment visit) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Subjective quality of life index
Time frame: Differences from baseline (visit 2, day -2) of Quality of life (WHO-QOL-BREF scores) to end of treatment (visit 5, day 14) and follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196).
Beck Depression Inventory (BDI-II)
Time frame: Difference from baseline (visit 2, day -2) of depressive symptoms to end of treatment (visit 5, day 14)
State Trait Anxiety Inventory (STAI)
Time frame: Difference from baseline (visit 2, day -2) of depressive symptoms to end of treatment (visit 5, day 14)
Patient reported outcomes (PRO)
Time frame: On visit 3 (day 1 of treatment), visit 4 (day 7 of treatment), visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
CBD plasma levels
Time frame: On visit 3 (day 1 of treatment) and visit 5 (day 14, end of treatment)
Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: On visit 3 (day 1 of treatment), visit 4 (day 7 of treatment), visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Time to relapse
Time frame: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Cumulative alcohol consumption during the follow-up period
Time frame: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Percent heavy drinking days during the follow-up period
Time frame: On visit 5 (day 14, end of treatment) and during follow up visits 6 (day 28), 7 (day 42), 8 (day 105), 9 (day 196)
Average weekly alcohol consumption during the follow-up period
Time frame: Every 7 days during the follow-up period of 182 days (+/- 7 days), starting after visit 5, i.e., end of treatment (day 14) and continuing until visit 9, i.e., end of follow up (day 196)
Maximum weekly craving during the follow-up period
Time frame: Every 7 days during the follow-up period of 182 days (+/- 7 days), starting after visit 5, i.e., end of treatment (day 14) and continuing until visit 9, i.e., end of follow up (day 196)
Neural Brain Activation during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Alcohol Craving during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Response Times during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Rates of Errors during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Rates of Correct Responses during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Omission Rates during functional magnetic resonance imaging
Time frame: Differences from baseline (visit 2, day -2) to visit 5 (day 14, end of treatment)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Feb 2026.
- Derived from this study: PubMed 40803733Vetter S, Weinberg J, Thomas BC, Kirchner M, Thalmann P, Klose C, Pfisterer M, Kolsch T, Oesterle S, Vollstaedt-Klein S, Koopmann A, Lenz B, Kiefer F, Link T, Bach P. Investigation of the combined effects of cannabidiol plus naltrexone on alcohol craving in alcohol dependence: study protocol of a phase II randomised, double-blind, placebo-controlled, parallel-group trial - ICONICplus Trial. BMJ Open. 2025 Aug 12;15(8):e106348. doi: 10.1136/bmjopen-2025-106348.
- Individual participant dataSharing planned: Yes. Individual de-identified data will be shared, specifically individual participant data that underlie the results of the trial (i.e. primary outcome data [OCDS-G scores]) will be made available with a respective data dictionary. Secondary Outcome data (e.g. fMRI data) will be made available on aggregated group level (e.g. for the purpose of meta-analyses). Related documents, specifically the study protocol, statistical analysis plan and analytic code will be shared in open-access online repositories. Aggregated data will be made available to publicly accessible repositories (Neurosynth.org), e.g. for the purpose of meta-analyses.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Patrick Bach, Prof. Dr. Dr. study director
Central Institute of Mental Health, Mannheim
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Cannabidiol capsules and Naltrexone (drug) in people with Alcohol Addiction and Alcoholism, run by Central Institute of Mental Health, Mannheim at 2 sites in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Patrick Bach, Prof. Dr. Dr. (+49-621-1703-0, patrick.bach@zi-mannheim.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Obsessive Compulsive Drinking Scale (OCDS-G) (time frame: The difference of alcohol craving between baseline (visit 2) and 14 days after the first treatment visit (visit 5) will serve as primary endpoint.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06845124, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Feb 2026.