Investigating the Neuropsychological Effects of 5-HT2a Antagonism

Recruiting now · Not applicable · Has a placebo group

Conditions studied: Healthy

In brief

Serotonin is an important chemical in the brain that helps control mood, sleep, and appetite. Most antidepressant medications work by affecting serotonin to help improve symptoms. A serotonin receptor is like a "lock" on the surface of brain cells, and serotonin acts like a "key" that fits into these locks. When serotonin binds to the receptor, it sends a signal that helps control different functions in the brain, like mood and behavior. There are different types of serotonin receptors, and each one affects different parts of the brain. Pimavanserin is a medication licensed in the United States of America for the treatment of patients with Parkinson's Disease. It has a very specific effect on one type of serotonin receptor (the serotonin 2a receptor). In this study, the investigators will use pimavanserin to understand more about this serotonin receptor, which may help develop new treatments for depression in the future. More specifically, the study will focus on how pimavanserin impacts cognitive functions such as memory, how we process emotional information and how we make decisions, and will compare these effects to a placebo (a treatment that doesn't have active ingredients).

Key facts

Study ID

NCT07022366

Run by

University of Oxford

People needed

80

Starts

2025-02-10

Expected to finish

2026-09-01

Last updated by the study team

2026-04-29

Who can join

Age: 18 and older, up to 45. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• Willing and able to give informed consent for participation in the research
• Aged 18-45 years
• Good vision and hearing
• Body mass index (BMI) within the range of 18-35kg/m2 (This is to ensure an appropriate pharmacokinetic profile for pimavanserin is achieved by all participants)
• Sufficiently fluent in English to understand tasks
• Willing to avoid drinking any alcohol the day before the research visit

You may not qualify if…

• Currently receiving or seeking treatment for any mental health condition
• Any past or current history of severe and/or serious psychiatric disorder, including but not limited to schizophrenia, psychosis, bipolar affective disorder, severe major depressive disorder, obsessive compulsive disorder (covered in SCID-5 assessment in screening procedures)
• ADHD requiring treatment with stimulant or other centrally-acting drugs
• Regular alcohol consumption of more than 21 units per week
• A head injury causing concussion or unconsciousness in the past 6 months
• Pregnancy / intention to become pregnant during the study or breastfeeding
• Any use of recreational drugs in the last three months
• Participation in any other drug study in the last three months
• Participation in any other study with the same tasks in the last year
• History of cardiac disease or cardiac arrhythmias
• Prolonged QTc interval on baseline ECG
• Current usage of other drugs known to prolong QT interval including Class 1A or 3 antiarrhythmics, e.g. certain antibiotics (getifloxacin, moxifloxacin)
• Current use of drugs that inhibit CYP3A4 (eg Clarithromycin. Diltiazem. Erythromycin. Fluconazole). Participants will be asked to avoid grapefruit juice in the week before the study.
• Current use of psychoactive medication that in the opinion of the Chief Investigator may interfere with the study measures
• History of, or current medical condition(s) which, in the opinion of the Investigator may interfere with the safety of the participant or the scientific integrity of the study, including epilepsy/seizures, brain injury, severe hepatic or renal disease, severe gastro-intestinal problems, Central Nervous System (CNS) tumours, severe neurological problems (e.g. Parkinson's disease; blackouts requiring hospitalisation);
• Any physical (including visual and auditory), cognitive or language impairment that would make complying with the study protocol challenging
• Excessive caffeine consumption, i.e., consumption higher than 8 cups of standard caffeinated drinks (tea, instant coffee) or higher than 6 cups of stronger coffee or other drinks containing methylxanthines such as coca cola or Red Bull per day;
• Smoking >10 cigarettes per day; or equivalent nicotine consumption
• Participant who is unlikely to comply with the clinical study protocol or is unsuitable for any other reason, in the opinion of the chief investigator.
• Inability to ingest up to 95mg of lactose
• Additional Exclusion Criteria for Participants in the Sleep Study Cohort:
• Unable to undergo cardiac monitoring
• Unable to wear the sleep patch device for full monitoring period
• Implanted neurostimulator

Where it is running

• Department of Psychiatry, University of Oxford — Oxford, United Kingdom (enrolling)

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.