Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

Cannabidiol for Bipolar Depression (CBD-BD)

Cannabidiol Adjunctive Therapy for Acute Bipolar Depression: A Randomized Double-Blind, Placebo Controlled Trial

Cannabidiol for Bipolar Depression (CBD-BD) (NCT05867849) is a Phase 3 interventional studying Bipolar Disorder, sponsored by University of British Columbia. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

Bipolar disorder (BD) is a lifelong condition characterized by recurrent episodes of depression and (hypo)mania. Periods of chronic and recurring depressive episodes are more common and can be severely disabling. Effective treatments exist; however, a significant portion of bipolar depressed patients do not respond to or have difficulty tolerating many of these interventions and thus look beyond established treatments to achieve symptom relief. Cannabidiol (CBD), a chemical from the Cannabis sativa plant, has shown to have some beneficial effects on mood symptoms in a few small studies which assessed its effects in other mental and physical health conditions, but no large studies have been conducted to assess its safety and efficacy in bipolar depression. Additionally, several clinical studies have shown CBD to be safe and tolerable. The primary objective of this study is to assess the effectiveness, safety and tolerability of cannabidiol in patients with bipolar depression (BD I or BD II) who have not responded to adequate trials with at least one first-line treatment for bipolar depression in comparison to those who will be treated with placebo. Placebo is an inactive substance that looks identical to the study medication but contains no therapeutic ingredient. This study is a randomized (like the flip of a coin), double-blind (you and the study team will not know which treatment arm you receive) study in which participants will receive either CBD or placebo added to their current treatment. Participants will have 5 clinical appointments and a phone appointment over a period of 10 weeks.

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Bipolar Disorder, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 360 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Males or females aged 19 to 70 years (inclusive). 2. DSM-5 diagnosis of BD I or BD II, AND a current major depressive episode confirmed by MINI 7.0.2 . 3. All patients must be taking either a mood stabilizer (i.e. lithium or valproate; lamotrigine monotherapy as a mood stabilizer is acceptable for BD II patients only and not for BD I) OR an atypical antipsychotic OR a combination of these (two mood stabilizers or a mood stabilizer plus an atypical antipsychotic), at therapeutic doses. Medications and therapeutic doses are: lithium, serum level 0.6-1.2 mEq/L; divalproex/sodium valproate, serum level 350-700 uM/L(45-125 mcg/ml); risperidone 2-6 mg/day; olanzapine 5-30 mg/day; quetiapine IR or XR 300-900 mg/day; aripiprazole 10-30 mg/day; cariprazine 1.5-6 mg/day; and ziprasidone 80-160 mg/day. Combinations of these medications as outlined above, or the combination of any of them with lamotrigine 100-400 mg daily, or the combination of a mood stabilizer plus asenapine 5-20 mg/day are also permitted. 4. Have received a minimum of 6-weeks treatment at adequate doses for treatment of current depressive episode with at least one CANMAT recommended first-line treatment for bipolar I disorder (i.e. lithium, lamotrigine, lurasidone, or quetiapine either as monotherapy or adjunctive therapy), or at least one first or second-line treatment for bipolar II depression (i.e. quetiapine, lithium, lamotrigine, sertraline, or venlafaxine as monotherapy or adjunctive therapy, or bupropion adjunctive therapy). 5. A MADRS score of ≥ 20 and a YMRS score of ≤ 12 (these cut off scores are standard in bipolar depression RCTs). 6. Inpatient or outpatient status. ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Males or females aged 19 to 70 years (inclusive). 2. DSM-5 diagnosis of BD I or BD II, AND a current major depressive episode confirmed by MINI 7.0.2 . 3. All patients must be taking either a mood stabilizer (i.e. lithium or valproate; lamotrigine monotherapy as a mood stabilizer is acceptable for BD II patients only and not for BD I) OR an atypical antipsychotic OR a combination of these (two mood stabilizers or a mood stabilizer plus an atypical antipsychotic), at therapeutic doses. Medications and therapeutic doses are: lithium, serum level 0.6-1.2 mEq/L; divalproex/sodium valproate, serum level 350-700 uM/L(45-125 mcg/ml); risperidone 2-6 mg/day; olanzapine 5-30 mg/day; quetiapine IR or XR 300-900 mg/day; aripiprazole 10-30 mg/day; cariprazine 1.5-6 mg/day; and ziprasidone 80-160 mg/day. Combinations of these medications as outlined above, or the combination of any of them with lamotrigine 100-400 mg daily, or the combination of a mood stabilizer plus asenapine 5-20 mg/day are also permitted. 4. Have received a minimum of 6-weeks treatment at adequate doses for treatment of current depressive episode with at least one CANMAT recommended first-line treatment for bipolar I disorder (i.e. lithium, lamotrigine, lurasidone, or quetiapine either as monotherapy or adjunctive therapy), or at least one first or second-line treatment for bipolar II depression (i.e. quetiapine, lithium, lamotrigine, sertraline, or venlafaxine as monotherapy or adjunctive therapy, or bupropion adjunctive therapy). 5. A MADRS score of ≥ 20 and a YMRS score of ≤ 12 (these cut off scores are standard in bipolar depression RCTs). 6. Inpatient or outpatient status. 7. All participants are required to agree to practice highly effective methods of contraception (i.e. hormonal contraceptives, intrauterine device or system, vasectomy and tubal ligation, or double barrier methods of contraception) OR agree to completely abstain from heterosexual intercourse. Females who do not have childbearing potential are required to be postmenopausal for at least 1 year before the screening visit (confirmed by an FSH test) OR surgically sterile. 8. The capability of understanding, consenting to and complying with study requirements. 9. All concomitant medication must be at a stable dose for two weeks prior to the randomization visit. Exclusion Criteria: 1. Current depressive episode greater than 12 months. 2. A history of rapid cycling, defined as ≥ 4 mood episodes in the preceding 12 months. 3. Current unstable or inadequately treated medical illness with the exception of current depression. 4. Recently started taking a CANMAT-recommended treatment for the management of acute bipolar depressive episode, but has not had a trial for a minimum of 6 weeks with adequate doses. 5. Recently (i.e. within the past 8 weeks) began structured psychotherapy (i.e. cognitive-behavioral therapy, interpersonal psychotherapy, family-focused therapy, or interpersonal and social rhythm therapy). 6. Recently (i.e. within the past 8 weeks) started taking a stimulant medication. Concomitant treatment with stimulant medication is acceptable provided that the dose has been stable for a minimum of 8 weeks and is taken as prescribed by a physician. 7. Current use of clozapine, tricyclic antidepressants, monoamine oxidase inhibitors, and first-generation antipsychotics. 8. A history of non-response or intolerance to CBD. 9. Current or past month daily use of CBD, or any product or drug that contains CBD. Occasional users will be included if they agree to refrain from using during the trial. 10. A history of non-response to electroconvulsive therapy for the current depressive episode. 11. A current diagnosis of other primary psychiatric disorders as assessed by a study investigator to be primary and causing greater impairment than BD. 12. A lifetime history of a primary psychotic disorder (e.g. schizoaffective disorder, bipolar subtype) according to DSM-5 criteria. 13. Patients who have met the DSM-5 criteria for a substance use disorder (except for nicotine or caffeine) within the past 6 months. 14. Significant active suicidal ideation (as evidenced by MADRS suicide item ≥ 4). 15. Pregnancy or lactation. 16. Liver function tests (AST and ALT) three times the upper limit of normal.

Treatments Being Tested

DRUG

Cannabidiol

Cannabinoid

OTHER

Placebo

Inactive substance

Locations (6)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

UBC Mood Disorders Centre

Vancouver, British Columbia, Canada

St. Joseph's Healthcare

Hamilton, Ontario, Canada

Providence Care Hospital

Kingston, Ontario, Canada

Sunnybrook Health Sciences Centre

Toronto, Ontario, Canada

Centre for Addiction and Mental Health (CAMH)

Toronto, Ontario, Canada

Douglas Mental Health University Institute

Montreal, Quebec, Canada

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05867849), the sponsor (University of British Columbia), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05867849 clinical trial studying?

Who can participate in NCT05867849?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05867849?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05867849. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05867849. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.