Cannabidiol for Bipolar Depression (CBD-BD)

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.