Recruitment of this patient population was more challenging than anticipated. The sponsor concluded that a sufficient amount of patients have completed the trial to demonstrate proof of concept in this patient population.

This study is a multicenter, open-label, single-arm Phase 2 clinical trial. Approximately 15 participants with clinically diagnosed bipolar disorder (BD) type II and experiencing a current episode of depression will be included in this study. The participants will receive an individualized dosing regimen (IDR) with at least one and up to three doses of GH001 administered within a single day.

Inclusion Criteria:

• Is male or female and in the age range between 18 and 64 years (inclusive) at screening
• Has a body mass index (BMI) in the range of 18.5 and 35 kg/m2 (inclusive) at screening
• Meets the trial criteria for bipolar II disorder and is experiencing a major depressive episode, as assessed by a trial psychiatrist or registered clinical psychologist

Exclusion Criteria:

• Has bipolar II disorder with rapid cycling (four or more episodes of hypomania or depressive episodes in previous 12-month period)
• Has, based on history, psychiatric assessment, and evaluation of the MINI, a current or prior diagnosis of bipolar I disorder, a manic episode, a psychotic disorder, MDD or other mood disorder with psychotic features, obsessive compulsive disorder, PTSD, autism spectrum disorder, borderline personality disorder, schizophrenia, delusional disorder, paranoid personality disorder, schizoaffective disorder, clinically significant intellectual disability, or any other psychiatric comorbidity that renders the patient unsuitable for the trial according to the investigator's judgment
• Has one or more first degree relatives with a current or previously diagnosed psychotic disorder, bipolar I disorder or MDD with psychotic features
• Has taken prohibited medication or prohibited dietary supplements within the specified timeframe prior to dosing
• Has previously experienced a significant adverse reaction to a hallucinogenic or psychedelic drug according to the investigator's judgment
• Has a clinically significant abnormality in physical examination, vital signs, ECG, or clinical laboratory parameters which renders the patient unsuitable for the trial according to the investigator's judgment