Ketamine Brain Imaging Study

About the study

Ketamine, a widely used anaesthetic, has emerged as a promising treatment in some people with treatment-resistant depression. However, it is not fully understood how ketamine works in the brain to cause these antidepressant effects.

The aim of this study is to understand more about why ketamine could be effective in treating treatment-resistant depression. To do this we will use brain imaging to see how brain activation patterns change when people have taken the treatment, and how this relates to any changes in their symptoms. This will help us understand more about the illness itself and how we might be able to treat it better.

What will it involve?

Taking part in the study involves attending for three visits to the Clinical Research Facility, King’s College Hospital at Denmark Hill, London.

• Visit 1: A screening visit (to assess whether you are suitable for the study). You will need to have a blood test, a heart tracing (ECG) and will be asked to complete some questionnaires.

• Visits 2 & 3: Two imaging visits where you will have a magnetic resonance imaging (MRI) scan to assess the effects of study medications on the brain. You will be given a low dose ketamine infusion while having an MRI scan. Before going into the scanner, you will be given naltrexone or a placebo tablet. Naltrexone is a drug that temporarily blocks opioid receptors. We are using naltrexone to test if the opioid system is involved in ketamine’s effects on the brain and its antidepressant effects.