SERENE: Does 5HT4R agonism have an acute procognitive effect in young adults with psychotic-like experiences: proof of concept study

A single dose of prucalopride, a drug already used for constipation, may temporarily sharpen thinking in young adults who have mild psychotic-like experiences. This matters because people with psychotic-like experiences—such as fleeting hallucinations or unusual beliefs—often struggle with memory, attention, and planning. These cognitive problems can emerge early, sometimes before full-blown psychosis develops, and no approved treatments currently target them. The study tests whether activating the serotonin 4 receptor in the brain can produce a rapid, measurable improvement in cognitive function. If the drug works, it would provide a proof of concept that a safe, existing medication could be repurposed to address cognitive symptoms in this group. That could open the door to larger trials and, eventually, a new treatment option for young people at risk of psychosis. The immediate impact would be on clinical research—showing whether this biological pathway is worth pursuing—rather than on everyday life. The study is a short-term, proof-of-concept experiment, not a treatment trial.