Actively Recruiting
Re-examining Maintenance Antipsychotic Treatment in Schizophrenia Comparing Extended Alternate Day Dosing to Daily Dosing A Randomized, Double-Blind Controlled Trial
Led by Centre for Addiction and Mental Health · Updated on 2026-04-13
120
Participants Needed
1
Research Sites
329 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating whether taking antipsychotic medication every other day is as effective as taking it daily for people diagnosed with schizophrenia spectrum or other psychotic disorders. This phase 4 trial aims to compare the usual daily dosing with an "extended" dosing schedule, where medication is taken one day on and one day off. The study also investigates whether this alternate dosing reduces side effects and improves overall wellbeing and functioning. Participants will be randomly assigned to either continue their usual daily antipsychotic treatment or switch to the alternate day dosing. The drugs studied include Risperidone, Olanzapine, and Paliperidone, with doses adjusted to individual needs and provided in capsules that maintain blinding. The trial lasts for one year, with study visits every two weeks during the first six months and every four weeks during the last six months, totaling 22 visits. During the study, participants will be regularly assessed using clinical rating scales and monitored for side effects, wellbeing, and functioning. The main outcome measure is clinical deterioration, evaluated at the start and after 52 weeks using the Brief Psychiatric Rating Scale - Expanded. Medication adherence, side effect frequency and severity, and symptom changes will be closely tracked throughout the trial to compare the two dosing schedules.
CONDITIONS
Official Title
"Extended" (Alternate Day) Antipsychotic Dosing
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Diagnosis of a schizophrenia spectrum or other psychotic disorder confirmed by DSM-5 and MINI
- Age 18 years or older
- Female participants of childbearing potential must use reliable contraception and have a negative pregnancy test at enrollment
- Male participants must agree not to father a child during the study
- Ability to communicate in English
- Capacity to provide written informed consent as assessed by MacCAT-CR
- Stabilized as outpatients on a single oral antipsychotic (risperidone, olanzapine, or paliperidone) at the same dose for at least 3 months
- Prescribed doses: risperidone 1-6 mg, olanzapine 5-20 mg, paliperidone 3-12 mg
- Evidence of adherence to current antipsychotic treatment
You will not qualify if you...
- Received depot antipsychotic injection within the last year
- Current substance use disorder diagnosis or positive drug screen for unprescribed drugs
- Electroconvulsive therapy (ECT) within the last 3 months
- Pregnancy or breastfeeding
- Neurological conditions such as dementia, multiple sclerosis, epilepsy, stroke, or traumatic brain injury
- Allergy to study drugs or their ingredients
- Allergy or severe intolerance to lactose
- Negative urine drug screen for olanzapine, risperidone, or paliperidone if applicable
AI-Screening
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Trial Site Locations
Total: 1 location
1
Centre for Addiction and Mental Health
Toronto, Ontario, Canada, M5T 1R8
Actively Recruiting
Research Team
C
Carol Borlido
G
Gary Remington, MD, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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