This study is now closed for recruitment. 

The brain’s ability to reshape and make new connections during adulthood is essential to our ability to learn new skills and form and access memories. This process, broadly described as neuroplasticity, can be disrupted by many different factors and is increasingly believed to be centrally involved in a number of mental health disorders and cognitive impairments. For example, in depression, connections between regions involved in cognitive, emotional and memory processing appear to be weaker, and the brain’s ability to form new connections in these regions also seems to be reduced.

As well as forming the basis for new treatments for mental health disorders, repairing the ability of the brain to make new connections may also be important in physical rehabilitation after stroke or other brain injuries. Ketamine, a safe and widely used anaesthetic, has been shown to be effective as a fast-acting antidepressant. There is a growing amount of evidence suggesting that ketamine’s anti-depressant action may stem from temporary enhancement of neuroplasticity, however, this is yet to be determined in humans.

Over a period of three weeks, participants who are deemed eligible at screening will partake in 6 study visits, including one high dose of ketamine. Across these six visits, there will also be two PET/MRI scans, three EEG recordings and a range of psychological measures (questionnaires and interviews). There will be a follow-up period of 1 month following the final study visit.

Key Inclusion Criteria:

• Male aged between 20 and 60 years old.
• Healthy, as determined by study medic.
• Right-handed.
• Abstinence from alcohol or any other psychoactive substance throughout the entire duration of the study, starting one week prior to the first visit.
• The participant is capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form.
• The participant is able to read, comprehend and record information written in English

Key Exclusion Criteria:

• Subject is mentally or legally incapacitated.
• Any current or history of significant injury to either the left or right hand that has resulted in any impairment of sensorimotor function.
• History of drug or other allergy that, in the opinion of the investigators, contraindicates their participation.
• History of or suffers from claustrophobia or feels that he will be unable to lie still on his back in the PET or MRI scanner for a period of 2 hours.
• Presence of a cardiac pacemaker or other electronic device or ferromagnetic metal foreign bodies as assessed by a standard pre-­MRI questionnaire.
• Clinically significant head injury (e.g., requiring medical or surgical intervention).

For any questions, please contact the study team on: ucbjketamine@imperial.ac.uk. Please only contact this email address with queries related to the ketamine study. For all other enquiries please email psychedelicresearch@imperial.ac.uk.