Understanding OCD · 6 min readReviewed by a licensed, ERP-trained OCD therapist · Updated October 2026

What is the Y-BOCS?

If you’ve looked into OCD treatment, you’ve probably seen these letters. Here’s what the scale is, what it measures, and why so many OCD therapists use it.

A woman sitting by a window, lost in thought

Where it comes from

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was published in 1989 by Wayne Goodman, Steven Rasmussen, Carolyn Mazure, Lawrence Price and colleagues at Yale and Brown universities. More than 35 years later, it’s still the most widely used measure of OCD severity in both research and treatment.

There’s also a newer second edition (Y-BOCS-II) and a version for kids and teens (CY-BOCS).

What it measures

The Y-BOCS isn’t a yes-or-no test for OCD. It measures how much OCD is affecting your life right now. It has two parts:

Part 1 · Symptom checklistA list of common obsessions and compulsions, including mental ones. It helps you and your therapist name exactly what your OCD looks like.

Part 2 · Severity scale10 questions, 5 about obsessions and 5 about compulsions, each scored 0 to 4. Together they give a total from 0 to 40.

The severity questions look at the same five areas for both obsessions and compulsions:

Time: how much of your day it takes up
Interference: how much it gets in the way of work, school, relationships or daily life
Distress: how upsetting it is
Resistance: how much you try to push back against it
Control: how much control you have over it

How scores are read

Clinicians commonly use these ranges for the total score:

0–7Subclinical

8–15Mild

16–23Moderate

24–31Severe

32–40Extreme

A score is a snapshot, not a label. It’s read alongside a full conversation with a clinician, which is how OCD is actually diagnosed.

How ERP therapists use it

At the startIt gives you and your therapist a clear picture of your symptoms and a starting score.

To build your planThe symptom checklist helps shape your exposure hierarchy, the step-by-step list you work through in ERP.

To track progressIt’s repeated during treatment, so you can see change in numbers, not just in how you feel on a hard day. Researchers often define a meaningful treatment response as a drop of 35% or more.

The point isn’t the number. It’s seeing that change is happening, even when OCD tells you it isn’t.

Why the scale isn’t on this siteThe Y-BOCS is copyrighted and can’t be posted online or turned into an online test without a license from its owners, OCD Scales, LLC. The versions you find online usually aren’t authorized, and the scale was built to be used with a clinician, not scored on your own. You can learn more at ocdscales.com.

What you can do instead

Take our free OCD reflection quiz. It’s private and isn’t a diagnosis, but it can help you make sense of your thoughts.
Ask any therapist you’re considering, “Do you use the Y-BOCS, and how will we track my progress?” Our worksheet, Questions to ask an OCD therapist, can help.
Read what your first ERP session is really like.

Want a real assessment?Find a licensed, ERP-trained clinician near you.

Find a therapist IOCDF directory

Education, not diagnosis or medical advice. Sources: Goodman WK, Price LH, Rasmussen SA, et al. The Yale-Brown Obsessive Compulsive Scale. I. Development, use, and reliability. Archives of General Psychiatry, 1989; Mataix-Cols D, et al. Towards an international expert consensus for defining treatment response, remission, recovery and relapse in OCD. World Psychiatry, 2016; OCD Scales, LLC. In crisis? Call or text 988 (U.S.).