On the “Gold Standard” of OCD Therapy
ERP is considered the gold standard of OCD treatment, due to the wide body of research supporting response rate, symptom reduction, overall outcomes, and durability. But the measurement tools and the attitudes about what constitute a gold star should be reconsidered.
General summary
Current research shows that traditional ERP is the most effective, "front-line" treatment for OCD.
The outcome measure
Efficacy in the research is defined by the Y-BOCS, or Yale-Brown Obsessive Compulsive Scale. The higher the score, the more severe the symptoms. While there are different versions of the Y-BOCS, most evidence is based on 10-item severity scale, each scored 0-4 (40 total points).
| Obsessions | Compulsions |
|---|---|
| 1. Time occupied by obsessive thoughts | 6. Time spent performing compulsions |
| 2. Interference from obsessions | 7. Interference from compulsions |
| 3. Distress caused by obsessions | 8. Distress if compulsions are prevented |
| 4. Resistance against obsessions | 9. Resistance against compulsions |
| 5. Control over obsessions | 10. Control over compulsions |
The following table shows scores grouped into severity bands.
| Total | Classification |
|---|---|
| 0–13 | Mild or lower |
| 14–25 | Moderate |
| 26–34 | Moderate–severe |
| 35–40 | Severe |
The following shows the general results:
| Outcome | General result |
|---|---|
| Response rate | Roughly 50–70% |
| Average symptom reduction | Approximately 35–50% reduction in Y-BOCS |
| Typical end-of-treatment score | Often around 12–18 on the 0–40 Y-BOCS |
| Durability | Gains are generally maintained for 6–24 months, although residual symptoms and relapse occur |
Critiques
Clearly the data show that traditional ERP is effective. It helps a lot of people. I have personally seen results from it for certain obsessions and compulsive behaviors.
But there are a few problems.
Y-BOCS is flawed
Let's take an example case: The patient feels they have sinned and redemption is not possible. They are highly distressed about going to hell. They worry about it all the time, and can't think of anything that will change the feared outcome.
They fill the Y-BOCS in the following way, according to how they they understand each item:
Obsessions
- Time occupied by obsessive thoughts - 4
This is straightforward. They are obsessing all the time.
- Interference from obsessions - 2
They have lost sleep obsessing over this problem, but since they haven't figured out what they can do about it, they continue life as usual.
- Distress caused by obsessions - 4
They are highly distressed throughout the day, each day
- Resistance against obsessions - 0
They don't really know what this means. They feel they can't resist, they are always obsessing over it.
- Control over obsessions - 0
They don't feel they have any control over their obsession either. It feels automatic.
Compulsions
- Time spent performing compulsions - 0
They believe they are obsessing all the time, but aren't doing anything about it.
- Interference from compulsions - 0
Since they think they aren't doing any compulsion, interference is 0.
- Distress if compulsions are prevented - 0
No compulsions, nothing to prevent.
- Resistance against compulsions - 0
Same as above.
- Control over compulsions - 0
Same as above.
The patient here has absorbed the common mis-understanding that they have "Pure-O" OCD, or that they are only obsessing, not doing compulsion.
You might see the problem here. This patient is extremely sick from OCD all the time, and their Y-BOCS score is 10, falling in the mild or clinically insignificant band.
ERP research is not immune to the replication crisis in behavioral psychology
While ERP still holds up as an effective treatment for OCD despite the replication crisis in behavioral psychology (many randomized controlled trial experiments in psychology over the past few decades cannot not be replicated), there are still some warnings that the data is weaker than suggested. See Effectiveness of psychological treatments for obsessive-compulsive disorders for more information.
Our bar for gold is really low
Before traditional ERP, OCD therapy had weak and unpredictable outcomes. The advent of behavioral intervention marked a breakthrough, and gave a lot of promise for patients who otherwise would not have any symptom relief.
Due to this history, and for other reasons, OCD is still viewed as a chronic disorder that is "happening to them" and that patients must live with. Therefore, practitioners believe that moving the needle at all is worth celebrating. But this can be taken too far. Some feel completely satisfied, and have misguided views when traditional ERP doesn't help.
This is just a view. Sure, we may possess genetic or other biological markers that support OCD, but from a psychological standpoint, the reverse could be equally possible — that OCD is almost completely treatable, but we haven't quite nailed the therapy. This we can call the symptom-free view.
From the typical viewpoint, an average response rate of 50%-70% looks incredible. From the symptom-free view, we should aim for 90-95%. Final results, however long they take, should be 0-1 SUDS (subjective units of distress) most of the time, not 12-18 Y-BOCS. These results should be durable for life.
My assessment of traditional ERP is more the tin or aluminum standard.