Proposed research by the University of Otago psychological medicine department will test a novel combination of dextromethorphan, which used to be used in many over-the-counter cold medicines, and bupropion, which is an antidepressant used to increase noradrenaline and dopamine levels.
Principal investigator and Otago postdoctoral research fellow Dr Neda Nasrollahi said the combination was recently approved by the Food and Drug Administration (FDA) in the United States and was showing promise for people with treatment-resistant depression.
However, it had not yet been approved by Medsafe.
"This innovative combination differs from conventional antidepressants in that improvements in mood occur more rapidly after starting treatment — typically within two weeks.
"Dextromethorphan is a strong N-methyl-D-aspartate (NMDA) antagonist and bupropion is an antidepressant that inhibits cytochrome P450 2D6, which increases the bioavailability of dextromethorphan."
Dr Nasrollahi said the study would also combine behavioural activation therapy — an evidence-based psychotherapy that focused on meaningful activities to reverse the cycle of withdrawal.
It operates on the principle that changing actions, rather than just thoughts, improves mood, energy and motivation.
The aim was to see if the drugs, combined with the therapy, could help treat depression and improve outcomes.
Dr Nasrollahi said she was now recruiting about 40 participants for the study.
"This is a novel trial for Aotearoa New Zealand.
"It has the potential to be a take-home alternative to ketamine for treatment-resistant depression, where long-term treatment is impractical due to its side effects and the necessity to be administered under supervision in a clinic.
"This increase in accessibility will benefit people in the community.
"If we can show that the combination of this novel treatment and psychological therapy is successful, particularly fast and effective, we believe it has the potential to reduce the personal, social and economic costs of mental distress in Aotearoa."
