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NCT04478838RecruitingPhase 4

"Extended" (Alternate Day) Antipsychotic Dosing

"Re-examining Maintenance Antipsychotic Treatment in Schizophrenia: "Extended" Antipsychotic Dosing"

Source: ClinicalTrials.gov · Last updated 13 Apr 2026

Brief summary (registry, in English)

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.

Status (registry)
Recruiting
Phase (registry)
Phase 4
Study type
Interventional
Enrollment
120 (estimated)
First submitted
16 Jul 2020
Start date
6 Jun 2022
Primary completion date
30 Sept 2027
Lead sponsor
Centre for Addiction and Mental Health
NCT number
NCT04478838

What you commit to

  • Study type: Interventional · Phase 4
  • Planned participants: 120
  • From 6 Jun 2022 to the primary completion date, 30 Sept 2027
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Prior treatment

  • (viii) negative urine drug screen result for Olanzapine or Risperidone or Paliperidone (if applicable)

Other illness

  • (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
  • (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

Other

  • (i) exposure to a depot AP within 1 year (i.e., no depot AP injection within the last year)
  • (iii) ECT within the last 3 months
  • (iv) pregnancy or lactation

Who the study is looking for

  • (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

Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Pick your city on the disease page to sort them by distance.

SiteCityCountrySite status
Centre for Addiction and Mental Health
Coordinator of this site? Confirm its status
TorontoCanadaRecruiting

This page is information, not medical advice. Discuss any trial with your doctor.