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Yale-Brown Obsessive Compulsive Scale (Y-BOCS)

The standard clinician-administered scale for measuring the severity of obsessive-compulsive disorder.

By Claire White

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What does the Y-BOCS measure?

The Y-BOCS asks about the time spent on, interference from, distress caused by, resistance to, and perceived control over obsessions and compulsions, rating each set separately. Every item is scored 0 to 4. An initial symptom checklist identifies which obsessions and compulsions are present but contributes no points. The scale rates severity, not symptom type and not diagnosis.

What does a Y-BOCS score mean?

The total runs from 0 to 40. Conventional bands, in wide use since the scale was published, read as follows.

Y-BOCS total score severity bands
Total scoreSeverity
0 to 7Subclinical
8 to 15Mild
16 to 23Moderate
24 to 31Severe
32 to 40Extreme

The Y-BOCS is the standard primary endpoint in OCD treatment trials, for medication and for cognitive behavioural therapy, and a reduction of 35 percent or more is the usual definition of response. The score is reference information for the care team.

How the Y-BOCS is administered

Administered by
A clinician, in a semi-structured interview
Time to administer
About 20 to 30 minutes
Structure
An unscored symptom checklist, then 10 scored severity items
Score range
0 to 40, from two subscales of 0 to 20
Cost
Free to take here.

Related instruments

Y-BOCS questions, answered

What does a Y-BOCS score mean?

The total runs from 0 to 40, combining a 0 to 20 obsessions score and a 0 to 20 compulsions score. Conventional bands read 0 to 7 as subclinical, 8 to 15 mild, 16 to 23 moderate, 24 to 31 severe, and 32 to 40 extreme. The score rates severity only. It does not diagnose OCD and does not identify which symptoms a person has.

How is the Y-BOCS scored?

Ten items, each rated 0 to 4. Five cover obsessions and five cover compulsions, and both sets ask the same five things: time occupied, interference with daily life, distress, resistance, and perceived control. The two sets of five are summed separately and then added.

What counts as a treatment response on the Y-BOCS?

Trials commonly define response as a reduction of 35 percent or more from the starting total. The Y-BOCS is the standard primary endpoint in OCD treatment research, for both medication and cognitive behavioural therapy.

Is the Y-BOCS free to use?

Yes. It is free to take here. The scale was published in full in the 1989 source articles and is widely reproduced in clinical practice and research.

Who can administer the Y-BOCS?

A clinician, as a semi-structured interview. The interview format matters, because the ratings depend on probing how much time symptoms occupy and how much the person resists them.

Evidence, psychometrics and provenance

Developed by Wayne Goodman and colleagues at Yale and Brown, and published in two 1989 papers: Part I covering development and reliability, Part II covering validity.

Psychometrics

Inter-rater reliability
Reported as excellent for the total and all 10 items (Goodman, 1989)
Internal consistency
Reported as high across item scores (Goodman, 1989)
Treatment response
A reduction of 35 percent or more is the usual response threshold

References

  1. 1.Goodman WK, Price LH, Rasmussen SA, Mazure C, Fleischmann RL, Hill CL, Heninger GR, Charney DS. The Yale-Brown Obsessive Compulsive Scale. I. Development, use, and reliability. Arch Gen Psychiatry. 1989;46(11):1006-1011.
  2. 2.Goodman WK, Price LH, Rasmussen SA, Mazure C, Delgado P, Heninger GR, Charney DS. The Yale-Brown Obsessive Compulsive Scale. II. Validity. Arch Gen Psychiatry. 1989;46(11):1012-1016.

This assessment uses a validated instrument and is reference information, not a diagnosis.