Study Information

What is this study about? 
pencilsThis study will determine the effects of the anti-inflammatory medication celecoxib – when added to participants’ usual treatment(s) – on OCD symptoms over 12 weeks. Celecoxib belongs to a medication class called non-steroidal anti-inflammatory drugs (NSAIDS). A common NSAID that many children have taken previously is ibuprofen, but it requires several doses per day to effectively reduce inflammation whereas celecoxib is taken only twice daily. NSAIDs may improve the function of parts of the brain involved in OCD symptoms. Early studies in adults with OCD and in children suggest possible benefits, but these medications have not been tested in children in a rigorous research study that compares them with a control or “placebo” treatment.

What happens in this study?
Participants and parents involved in this study will complete an initial phone interview lasting 30-60 minutes. Three in-person or remote study visits with a Research Assistant and study doctor will take place over the course of 12 weeks (~30 minutes each). Online questionnaires will be completed by parents and participants before each study visit (~40 minutes each). Baseline and 12 week blood work is required to ensure safe use of the medication and measure inflammatory markers. Height and weight will also be measured before treatment.

Participants will be randomized to either celecoxib or placebo, an inactive substance that looks identical. These treatments will be taken as a capsule (whole or sprinkled on food) twice daily for 12 weeks. Participants and study team members involved in their care will not know which treatment they are receiving. An optional open label extension will be offered to participants at the end of the trial where they will receive the study drug celecoxib for an additional 12 weeks, with a final study visit at the end of this 12 weeks period. Participants, parents, and study doctors will monitor for side effects and OCD symptoms.

Of note, participating in this study does not require pausing or interrupting current treatment for OCD, either through medication or CBT. If you choose to participate, you will be adding celecoxib or the placebo to treatment as usual.

Who is eligible for this study?
Children and youth in BC between the ages of 7-18 with a previous diagnosis of OCD and current symptoms may be eligible to participate. A diagnostic interview and blood work is required to help ensure potential participants do not have medical conditions that would make their participation unsafe. Study participation is entirely voluntary. It will not affect the usual medical care you are receiving.

How can I get involved?
For further information, please contact the research team at or call 604-875-2000 ext. 3068. The Principal Investigator for this study is Dr. Evelyn Stewart.

Information and Consent/Assent Forms

Click on the links below to download the forms. 

Adolescent Assent Form
Child Assent Form
Parent Consent Form
Participant Consent Form

Want to learn more?
For more background information on the role of inflammation and celecoxib in OCD, check out the posters and publications below.

Published peer-reviewed papers

  1. Celecoxib versus placebo as an adjunct to treatment-as-usual in children and youth with obsessive-compulsive disorder: A single-site randomized quadruple-blind phase II study
  2. Commentary on neuroinflammation and non-steroidal anti-inflammatory drugs (NSAIDs) in neuropsychiatric disorders
  3. Severe symptoms predict salivary interleukin-6, interleukin-1β, and tumor necrosis factor-α levels in children and youth with obsessive-compulsive disorde

Posters and Presentations​​​

  1. Research poster for ACE-OCD study (Awarded Top Oral Presentation at UBC Psychiatry Research Day 2021; BCCHR Brain, Behaviour, & Development Research Day 2021)
  2. Salivary biomarkers in childhood-onset obsessive compulsive disorder: Analyses of pro-inflammatory cytokines in a pilot cohort
  3. ACE-OCD study overview summary slides
  4. Narrated poster (Awarded Top Poster at UBC Psychiatry Research Day 2020; Psychoneuroimmunology Research Society 2021)
  5. UBC Neuropsychiatry Rounds 2022

Blog Posts

  1. Kelty Mental Health Blog Post - Hot off the press: the heated debate about OCD and inflammation


Visit ClinicalTrials.Gov for more information on the ACE-OCD study.