Using Topiramate to Manage Weight and Symptoms in Schizophrenia

Topiramate in Treatment Refractory Psychotic Illness: Effects on Weight Gain and Psychopathology

Not applicable Interventional Centre for Addiction and Mental Health · NCT02808533

This study is testing if the medication Topiramate can help people with treatment-resistant schizophrenia or schizoaffective disorder manage their weight and improve their mental health while they are on clozapine.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment50 (estimated)
Ages17 Years to 59 Years
SexAll
SponsorCentre for Addiction and Mental Health Academic / other
Locations1 site (Toronto, Ontario)
Trial IDNCT02808533 on ClinicalTrials.gov

What this trial studies

This study investigates the effects of Topiramate, an anticonvulsant medication, on weight and psychopathology in individuals with treatment-resistant schizophrenia or schizoaffective disorder who are currently taking clozapine. The research aims to determine whether Topiramate can serve as an effective adjunctive treatment to mitigate weight gain and improve mental health symptoms in this patient population. Participants will be randomly assigned to receive either Topiramate or a placebo, and various health metrics will be monitored throughout the study.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 17-59 with schizophrenia or schizoaffective disorder who have been on clozapine for at least 12 weeks and have a BMI of 25 or greater.

Not a fit: Patients with alcohol use disorder, significant liver or renal dysfunction, or those who have previously not tolerated Topiramate may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new treatment option that helps manage weight and improve mental health outcomes for patients with treatment-resistant schizophrenia.

How similar studies have performed: While there is some evidence supporting the use of Topiramate in treatment-resistant schizophrenia, this specific approach is relatively novel and has not been extensively tested in controlled trials.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Schizophrenia or Schizoaffective disorder
* 17-59 years of age
* Clozapine treatment for at least 12 weeks at a dose 350 mg/d or greater and/or plasma clozapine levels of 300 ng/mL or greater
* CGI must be 4 or higher and/or GAF \< 50
* BMI greater than or equal to 25

Exclusion Criteria:

* Alcohol use disorder
* Patients with liver, or renal dysfunction
* Females of child bearing age not on a regular contraceptive, females who are nursing
* Clinical or laboratory evidence of uncompensated cardiovascular, endocrine, hematological, or pulmonary disease.
* HbA1c \> 9%, or symptomatic hyperglycemia with metabolic decompensation
* Prior lack of efficacy or tolerability of Topiramate
* Addition of new hypoglycemic or lipid lowering medication within 2 months of starting study
* Patients treated with Valproic Acid
* Patients treated with hydrochlorothiazide
* Switch in antipsychotic medications within 3 months of study entry
* Major medical or surgical event within the preceding 3 months
* History of renal stones
* Use of Carbonic Anhydrase Inhibitor
* History of glaucoma
* Acute Suicidal risk

Where this trial is running

Toronto, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Schizophrenia, Schizoaffective Disorder
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.