Actively Recruiting
Do Antipsychotics Block Insulin Action in the Brain: is it a Class Effect?
Led by Centre for Addiction and Mental Health · Updated on 2026-04-02
35
Participants Needed
1
Research Sites
17 weeks
Total Duration
On this page
Sponsors
C
Centre for Addiction and Mental Health
Lead Sponsor
T
The Physicians' Services Incorporated Foundation
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are investigating how the antipsychotic medication haloperidol may affect insulin action in the brain. Insulin helps regulate blood sugar levels, and in the brain, it influences cognition and information processing. Since haloperidol and similar medications can cause metabolic side effects like weight gain, type 2 diabetes, and heart disease, this study aims to understand how these drugs might interfere with insulin's brain effects to help reduce metabolic risks in the future. Participants will take either haloperidol or a placebo capsule by mouth at night for 7 days, with haloperidol doses gradually increasing up to 2 mg. During MRI scanning visits, participants will receive intranasal insulin lispro or saline to assess insulin effects in the brain. The study uses a randomized, quadruple-blind design comparing haloperidol to placebo, with careful monitoring over up to 5 months. Throughout the study, researchers will measure brain connectivity between specific brain regions, metabolic outcomes like BMI, waist circumference, glucose, insulin, C-peptide, HbA1c, and insulin resistance. They will also assess haloperidol blood levels, sleepiness, cognitive tests, movement scales, and side effects. Participants will complete various assessments and scans during the study, which lasts up to five months from enrollment.
CONDITIONS
Brief Title
Do Antipsychotics Block Insulin Action in the Brain: is it a Class Effect?
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Must have the capacity to provide informed consent
- Must sign and date the informed consent form
- Willingness to comply with all study procedures
- Age between 18 and 35 years
- Body Mass Index (BMI) between 18.5 and 24.9 kg/m2
- Both sexes are eligible
You will not qualify if you...
- History of psychiatric illness or substance use disorder
- Pre-diabetes or diabetes, or use of anti-diabetic drugs
- Impaired insulin sensitivity (HOMA-IR 2.5)
- Family history of diabetes in a parent or sibling
- Use of weight reducing agents
- History of kidney or liver disease
- History of blood cell disorders
- Irregular menstrual cycles or certain gynecological conditions
- Current use of hormonal birth control or hormone treatments
- Pregnant, recently gave birth, or breastfeeding without sufficient menstrual cycles post-breastfeeding
- Major medical or surgical event within the last 6 months
- Contraindications to MRI such as metal implants or claustrophobia
- Known allergies or contraindications to study drugs
- Use of medications increasing risk of blood sugar changes
- Medical conditions warning against haloperidol, lorazepam, benztropine, or insulin
- Use of prohibited medications as listed in haloperidol product monograph (e.g., barbiturates, narcotics)
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 7 days per treatment period
Participants will self-administer haloperidol or placebo orally at night over 7 days, with haloperidol titrated up to 2 mg.
2 treatment periods with medication administration, separated by a washout period
Duration - Up to 5 months from enrollment
Participants undergo MRI scanning visits where intranasal insulin lispro or saline are administered to assess brain insulin action and metabolic outcomes.
Multiple MRI scanning visits during the study period
Trial Site Locations
Total: 1 location
1
Centre for Addiction and Mental Health
Toronto, Ontario, Canada, M6J 1H3
Actively Recruiting
Research Team
M
Mahavir Agarwal, MBBS, MD, PhD
M
Maria Papoulias, MSc
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
OTHER
Number of Arms
2
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