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Recruiting Phase 4 NCT04478838

NCT04478838 "Extended" (Alternate Day) Antipsychotic Dosing

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Clinical Trial Summary
NCT ID NCT04478838
Status Recruiting
Phase Phase 4
Sponsor Centre for Addiction and Mental Health
Condition Schizophrenia and Related Disorders
Study Type INTERVENTIONAL
Enrollment 120 participants
Start Date 2022-06-06
Primary Completion 2027-09-30

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
RisperidoneOlanzapinepaliperidone

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

Phase 4 studies follow an already-approved treatment in real-world conditions to monitor long-term safety and effectiveness.

This trial targets 120 participants in total. It began in 2022-06-06 with a primary completion date of 2027-09-30.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The study wishes to examine whether "extended" antipsychotic treatment, in this case, antipsychotic treatment every other day, is as effective as daily treatment. It is also evaluating whether there may be differences in terms of side effects. Participants will be randomly assigned to either the treatment as usual group (i.e., taking antipsychotic daily) or the extended dosing group (i.e., taking antipsychotic one day on, one day off). That means, like flipping a coin, there is a 50/50 chance that participants will continue on daily dosing of your antipsychotic or have it switched to every other day dosing. This study will last for 1 year. Participants will be evaluated at the beginning and every two weeks during the first 6 months, with visits once every 4 weeks for the final 6 months. In total, participants will make 22 visits over 52 weeks to the investigator's office. The investigators hypothesize that with ED, there will be no change in symptom severity but improvement in the frequency and severity of side effects, wellbeing, and functioning.

Eligibility Criteria

Inclusion Criteria: (i) A primary diagnosis of a Schizophrenia Spectrum or Other Psychotic Disorder as defined by the DSM-5 diagnosis and confirmed by the MINI (Version 7.0.2) (ii) age 18 or older (iii) female participants of childbearing potential must be using a reliable method of contraception and have a negative pregnancy test at the time of enrolment and must, in the investigator's opinion, practice a clinically accepted, reliable method of contraception during this study. Male participants must not father a baby during their time in the study (iv) ability to communicate in English (v) capacity to provide written, informed consent, as assessed using the MacCAT-CR at time of consent (vi) stabilized as outpatients with a single oral AP (risperidone or olanzapine or paliperidone\*) at the same dose for ≥3 months i. On a prescribed risperidone dose of between 1-6mg, or a prescribed olanzapine dose of between 5-20mg, or a prescribed paliperidone 3-12mg (vii) evidence of adherence with current AP treatment Exclusion Criteria: (i) exposure to a depot AP within 1 year (i.e., no depot AP injection within the last year) (ii) Current diagnosis of substance use disorder according to DSM-5 criteria (verified through the MINI for Psychotic Disorders (Version 7.0.2) and a positive drug screen for street and /or prescription drugs not prescribed to the participant by treating physicians (iii) ECT within the last 3 months (iv) pregnancy or lactation (v) neurological condition (dementia including Alzheimer's disease, multiple sclerosis, epilepsy, stroke, or traumatic brain injury) (vi) allergy to the study drugs and their excipients (vii) allergy (e.g., galactosaemia) or severe intolerance to lactose (viii) negative urine drug screen result for Olanzapine or Risperidone or Paliperidone (if applicable)

Contact & Investigator

Central Contact

Carol Borlido

✉ carol.borlido@camh.ca

📞 416-535-8501

Principal Investigator

Gary J Remington, MD, PhD

PRINCIPAL INVESTIGATOR

Centre for Addiction and Mental Health

Frequently Asked Questions

Who can join the NCT04478838 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, studying Schizophrenia and Related Disorders. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT04478838 trial and what does that mean for participants?

Phase 4 studies are conducted after a treatment has been approved. They monitor long-term safety and real-world effectiveness in a broader patient population.

Is NCT04478838 currently recruiting?

Yes, NCT04478838 is actively recruiting participants. Contact the research team at carol.borlido@camh.ca for enrollment information.

Where is the NCT04478838 trial being conducted?

This trial is being conducted at Toronto, Canada.

Who is sponsoring the NCT04478838 clinical trial?

NCT04478838 is sponsored by Centre for Addiction and Mental Health. The principal investigator is Gary J Remington, MD, PhD at Centre for Addiction and Mental Health. The trial plans to enroll 120 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: April 2026  ·  Data Methodology