Feasibility of oral ketamine for bipolar depression: a 20-week open-label study

This open-label Phase II trial (n=30) will investigate the feasibility, safety, and antidepressant effects of oral ketamine (starting at 1 mg/kg, up to 2 mg/kg) in adults with bipolar depression.

Conducted by the University of Otago in New Zealand, the study will administer oral ketamine twice weekly for up to 8 weeks under clinical supervision. Dosing begins at 1 mg/kg, mixed with juice and consumed over 30–60 minutes, and may increase based on tolerability and depressive symptom scores, as assessed by the Montgomery–Åsberg Depression Rating Scale (MADRS). If patients show significant symptom reduction, dosing frequency may be lowered to weekly.

The primary goal is to assess feasibility based on recruitment, retention, and adherence rates, as well as improvements in depressive symptoms. Secondary outcomes will evaluate relapse prevention, cognitive functioning, quality of life, and potential for ketamine dependence. Participants will be monitored for safety using clinical assessments for dissociation, mood elevation (via the Young Mania Rating Scale), and bladder symptoms. The study aims to address the gap in treatment options for bipolar depression using a more accessible and potentially scalable oral formulation of ketamine.

Topic Bipolar Disorder Depression Treatment-Resistant Depression
Compound Ketamine
Country New Zealand
Visit trial
Status Not yet recruiting
Results Published No
Start date 23 June 2025
End date 12 July 2027
Phase Phase II
Design Open
Type Interventional
Generation First
Participants 30
Sex All
Age 18- 65
Therapy No

Trial Details

Oral ketamine will be administered twice-weekly in the clinical research units of the Departments of Psychological Medicine (Dunedin or Christchurch) for a total of 8-weeks. Each dose will be administered under the oversight of a healthcare professional. Oral ketamine dose will be determined by the MADRS and tolerability using an established protocol as follows. Oral Ketamine to commence at 1 mg/kg mixed with 50 ml orange juice and sipped over 30–60 minutes. Initial dosing twice weekly (with gaps of 3 and 4 days between doses). If first dose is tolerated and if the Montgomery Asberg Depression Rating Scale (MADRS)>6 on follow-up (indicating mild depression or greater), increase dose to 1.5 mg/kg twice weekly. If second dose is tolerated and if the MADRS>6 on follow-up, increase dose to 2 mg/kg twice weekly. If the MADRS is <6 on follow-up, dosing can be reduced to weekly intervals. Dosing to be supervised by administering clinician (study nurse or doctor) and discussed with the supervising psychiatrist as needed and if ketamine is not tolerated.

Trial Number ACTRN12625000267459p

Data attribution

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