Depression affects around half of people with Parkinson’s disease (PD). However, existing antidepressants are not effective in treating these symptoms in PD and new treatments are urgently needed. Ketamine, a drug that has traditionally been used as an anesthetic, is currently being employed as an antidepressant based on its ability to rapidly reduce depressive symptoms. Given its significant potential as an effective treatment for depression in PD, we will test ketamine for the first time in a controlled, clinical trial and use imaging techniques to determine how it works in the brain.
We hypothesize that, compared to a placebo, a course of ketamine treatment will result in a significant decrease in symptoms of depression in PD. We further hypothesize that ketamine will increase neural connections and reorganize neuronal networks in the brain.
Participants with PD and symptoms of depression will be randomized to receive either treatment with ketamine or a placebo at two doses per week, for three weeks. We will compare participants’ symptoms of depression before and after the treatment to assess the effect of ketamine vs. placebo on alleviating depression, and we will determine whether ketamine is an effective drug for depression in PD. In a subset of participants, we will carry out brain imaging before and after treatment to determine the effects ketamine has on the brain.
Impact on Diagnosis/Treatment of Parkinson’s Disease:
To improve quality of life in people with PD, we need to more effectively treat symptoms of depression. Our findings could lead to the use of ketamine as a new rapidly-acting and effective antidepressant, changing the way that depression is treated in PD.
Next Steps for Development:
Findings from this first trial would lead to larger replication studies, a phase 3 trial and, ultimately, to clinical application of ketamine for the treatment of depression in people with PD.