This study is testing a medicine called troriluzole to see if it helps people with Obsessive Compulsive Disorder (OCD). OCD is a condition where someone has unwanted thoughts or feels they must do certain actions repeatedly. Placebo is a harmless pill with no medicine used to compare results. Participants in the study should be diagnosed with OCD for at least one year. They should have tried standard OCD medicines but still need help. They must be in good health based on exams and tests. People who have been through more than two failed OCD treatments or have other mental health conditions like schizophrenia cannot join. Also, if someone has already tried troriluzole, they are not eligible.

• The study involves additional treatment alongside current OCD medication.
• Participants must not have certain other mental health conditions.
• Participants should expect to be available and healthy to complete the study.