AuthorisedTherapeutic exploratory (Phase II)Interventional

The Role of Serotonin 4 Receptor Agonism in Regulating Mood and Cognition in Depression in women (RECAP-D)

Depression is a common condition that causes persistent sadness, low energy, and problems with memory and concentration. While standard antidepressants help many people, they do not work for everyone and often do not fully clear up memory issues or brain fog. This clinical trial is testing a medicine called prucalopride. Prucalopride works on a specific serotonin receptor in the brain that is thought to help with both mood and thinking. Researchers want to see if taking prucalopride, either alongside a well-known antidepressant called sertraline or on its own, helps women recover better than a dummy tablet (placebo). Over 8 to 12 weeks, the study team will track participants' mood and memory. They will also use brain scans and a special smartwatch to monitor sleep, activity, and brain connections. The goal is to find new ways to help women with depression feel better and think more clearly.

At a glance

Status

Authorised

Phase

Therapeutic exploratory (Phase II)

Sponsor

Region Hovedstaden

Enrolment target

106

Start

17 Sep 2026

Major depressive disorder

What is this study about?

Major depressive disorder is more than just feeling down for a few days. It is a serious illness that affects millions of people across the UK. Alongside feelings of deep sadness and exhaustion, depression frequently causes problems with thinking, such as forgetfulness, poor focus, and slower decision-making. Current antidepressant medicines do not always improve these thinking symptoms, leaving many people struggling with daily tasks even after their mood starts to lift.

Scientists believe that targeting a specific brain chemical pathway, known as the serotonin 4 receptor, could be key to boosting both mood and brain function. This study is testing prucalopride, a medication that activates this pathway. Although prucalopride is already approved for another medical use, research suggests it might also encourage healthy connections between brain cells and improve memory.

The trial is studying adult women to see how prucalopride works when used alone, alongside the common antidepressant sertraline, or compared to a dummy pill (placebo). By using detailed memory tests and modern brain imaging, researchers hope to see if this approach creates real, measurable changes in brain networks and daily functioning. If successful, this research could pave the way for brand-new treatment options that tackle both the emotional and mental challenges of depression.

Key takeaways

Tests whether the medicine prucalopride can boost mood and memory in women with depression.
Compares prucalopride, the standard antidepressant sertraline, and a dummy pill.
Open to women aged 18 and over who have major depressive disorder.
Involves memory tests, mood questionnaires, brain scans, and wearing a health-tracking watch.
Lasts between 8 and 12 weeks, and taking part is completely voluntary.

Who may be eligible?

This study is open to women aged 18 and older who are currently experiencing major depressive disorder (clinical depression). Because depression can affect women differently and the brain systems being studied may be influenced by female biology, only women are being invited to take part at this stage.

To join, you should be experiencing ongoing depressive symptoms that affect your day-to-day life and memory. You will need to be able to attend hospital visits for appointments, memory tests, and brain scans.

You may not be able to participate if you have certain other medical or neurological conditions, or if you cannot safely have brain scans (such as an MRI). The study doctors will carefully review your full medical history and current medications to confirm if taking part is safe for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am a woman aged 18 or older.
I am currently experiencing major depression.
I struggle with low mood and notice problems with my memory or concentration.
I am willing and able to attend clinic visits for memory tests and brain scans.
I am comfortable taking daily tablets and wearing an activity-tracking watch.

Answer every question to see your result.

What does participation involve?

Taking part in the study lasts between 8 and 12 weeks. During this time, you will be asked to take study tablets each day. Depending on which group you are placed in, these tablets may contain prucalopride, sertraline, or a harmless dummy pill (placebo). You will have regular appointments with the research team to check your safety, discuss how you are feeling, and complete questionnaires about your mood. You will also do several memory and word tasks to measure your thinking skills. During the trial, you will be invited for brain scans (including an MRI and a PET scan) so researchers can take safe, detailed pictures of your brain activity and nerve connections. Additionally, you will be given a lightweight smartwatch to wear, which tracks your pulse, sleep quality, and daily movement. After your treatment ends, there will be follow-up checks to see how you are doing.

Potential risks and benefits

You may experience improvements in your mood or memory during the study, but this cannot be guaranteed. However, the information gathered will help doctors develop better treatments for women with depression in the future. As with all medications, there is a chance of side effects from sertraline or prucalopride, such as stomach upset, headache, or tiredness, which the study doctors will explain fully before you begin. Brain scans can sometimes feel noisy or claustrophobic, but the team will support you throughout. Taking part is completely your choice, and you are free to leave the trial at any time without giving a reason and without your normal NHS care being affected.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Denmark

Common questions

What is prucalopride?

Prucalopride is a medicine that stimulates a specific chemical messenger in the body called serotonin. Scientists have discovered that it may also help strengthen connections in the brain that manage mood and memory.

What is a placebo and will I receive one?

A placebo is an inactive tablet that looks just like the real medicine. Clinical trials use them to see if changes in health are truly caused by the new medicine. You may receive a placebo depending on which group you are placed in.

Why is the study only open to women?

Depression is more common in women, and hormones can influence brain chemistry. Focusing on women helps the researchers get clearer results about how this specific brain pathway works.

Are the brain scans safe?

Yes. MRI scans use magnets and radio waves and are very safe. PET scans use a tiny, strictly controlled amount of a tracking substance to look at brain connections. The research team will check all safety guidelines with you beforehand.

Can I stop taking part if I change my mind?

Yes, you can leave the study at any time. Your usual medical treatment and your relationship with your regular doctors will not be affected in any way.