A Mechanistic Study to Assess a Single Dose of CYB003 in Participants With Depression and Anxiety

Inclusion Criteria: * Participant is assigned female or male at birth. * Participant is aged between 21 to 65 years, inclusive, at Screening. * Participant has a BMI of 18 to 30 kg/m2, inclusive, at Screening. * Participant is ≥60 kg. * Participant has a diagnosis of MDD (as defined in the DSM-5 established through a clinician interview that includes the Mini-International Neuropsychiatric Interview) * Depression severity moderate to severe based on MADRS score ≥21. * Anxiety severity moderate to severe based on GAD-7 ≥10. * Inadequate response to current antidepressant medication in current episode of depression. * Participant has been on a stable dose (no more than 50% change) of antidepressant medication (SSRI or SNRI) in the last month prior to Screening. * Participants capable of producing sperm must use a condom during the trial and for 3 months after their dose of trial medication, if their partner is a person of childbearing potential. In addition, their partner of childbearing potential must use a highly effective method of contraception (i.e., failure rate less than 1% when used consistently and correctly) from dosing until 3 months following dosing. * Participants of childbearing potential must agree to use a highly effective method of contraception (i.e., failure rate less than 1% when used consistently and correctly) in combination with use of a condom by a partner who is capable of producing sperm, during the trial and for 3 months after dosing. Such participan…