A core component of schizophrenia is neurocognitive impairment. The cognitive deficits are prominently seen in memory, attention, working memory, problem solving, processing speed and social cognition. Atypical antipsychotics continue to be the mainstay of treatment in schizophrenia.

Promising areas for future research include search for new compounds for cognition enhancement. Prucalopride, a highly selective 5HT4 receptor agonist is a potential drug and its effect on cognition in patients with schizophrenia needs to be studied.

An open label, pilot study involving 34 patients with schizophrenia diagnosed as per DSM 5 criteria. The participants will receive Tab. Prucalopride one milligram (1 mg) for a duration of four weeks along with their existing treatment regimen with antipsychotics.

Assessments includes PANSS and BACS at baseline and at the end of 4 weeks. The effect of prucalopride on cognitive functioning in patients with schizophrenia is studied.

Prucalopride acts as a high affinity, high selective 5-hydroxy tryptamine receptor agonist. It is a gastrointestinal prokinetic drug predominantly used for constipation. In this study, the effect of prucalopride on cognitive functioning in schizophrenia is studied.

Participants who are diagnosed with schizophrenia, attending consultation at the outpatient department (OPD) of Psychiatry at K.S. Hegde Hospital and Nitte Rural Medical and Psychiatry Centre will be invited to participate in the study through their treating consultant. Interested participants and their Legally acceptable representative (LAR) will be administered the written informed consent. The participant will be screened and on fulfilling the inclusion and exclusion criteria will be enrolled into the study.

Socio demographic details will obtained from the participants. Baseline laboratory analysis which includes complete blood count, random blood sugar, liver function test, renal function test, urine analysis, ECG will be done for all the participants to screen for fitness. Urine pregnancy test will be done for women participants in the reproductive age group.

Positive and Negative Syndrome Scale (PANSS) will be administered to the participants.

Brief assessment of Cognition in Schizophrenia (BACS) will be administered in the following order i. List learning ii. Digit sequencing task iii. Token motor task iv. Verbal fluency: Category Instances, Controlled Oral Word Association Test v. Tower test vi. Symbol coding The study drug Tab. Prucalopride 1 mg (30 tablets) will be dispensed to the participant. They will be explained to take one tablet of 1 mg Prucalopride per oral in the morning. The participants will continue their antipsychotic regimen as per orders of their consultant and will continue to purchase their psychiatric medications as earlier. At the end of week 1, participants will be assessed for side effects via telephonic conversation.

At the end of 4 weeks, the participants will be scheduled for the assessments. Laboratory analysis, PANSS and BACS will be administered. Any side effects to the drug will be assessed.

Inclusion Criteria:

• Diagnosed as schizophrenia by DSM 5 criteria using Structured Clinical Interview for DSM disorders
• Age between 18 to 55 years
• A minimum of one year of duration of illness
• Clinically stable with a stable therapeutic dose for at least 3 months prior to the recruitment
• Participants who can read and write English or Kannada

Exclusion Criteria:

• Participants who are acutely symptomatic and are uncooperative for assessments
• Co morbid with other psychiatric illness including mood disorders and substance use disorders except tobacco
• Participants already diagnosed with Intellectual Disability Disorder, head injury
• Participants administered MECT (modified electroconvulsive therapy)
• Participants with sensory impairments
• Use of Donepezil, Rivastigmine, Memantine, Benzodiazepines
• Participants already on prucalopride
• Participants with contraindications to prucalopride
• Diagnosed with gastrointestinal disorders like Ulcerative colitis, Crohn's disease, Intestinal ulcers
• Use of concomitant herbal remedies, alternative medicines
• Women who are pregnant or lactating
• Current history of suicidal ideation, intention or attempts

Individual participant data that underlie the results reported in the article, after deidentification (text, tables, figures, and appendices).

One year after publication of this study.

For individual participant data, meta-analysis.