Cannabidiol for Bipolar Depression (CBD-BD)

This is a Phase 3, 6-week, double-blind, parallel group randomized controlled trial to assess the efficacy, safety and tolerability of adjunctive CBD vs placebo in patients with acute bipolar depression (BD I or BD II) who have not responded to adequate trials with at least one 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). After the baseline visit, patients who meet the eligibility criteria will enter a 6-week double-blind treatment phase during which participants will be randomized to adjunctive CBD or identical placebo. Participants will be assessed at the screening visit, baseline visit, weeks 2, 4, and 6, or endpoint visit. All participants will receive a follow-up telephone call 2 weeks after the 6-week study endpoint or early termination visit to assess well-being. All participants will continue treatment with their mood stabilizer and/or atypical antipsychotic as prescribed by their treating physicians.