OCD – criteria for diagnosis, assessment test

by Abbas Jahangir · July 6, 2024

Criteria for a diagnosis of OCD (obsessive compulsive disorder)

To be diagnosed with obsessive-compulsive disorder, the following DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) criteria must be met:

presence of obsessions, compulsions, or both
obsessions and compulsions take at least 1 hour per day
obsessions or compulsions cause distress or affect your participation in social activities, work duties, or other life events
the symptoms are not caused by substances, alcohol, drugs, or another medical condition
the symptoms are not explained by another mental condition, such as generalized anxiety disorder, eating disorder, or body dysmorphic disorder.

How is OCD (obsessive compulsive disorder) diagnosed?

Steps to diagnose OCD may include:

Psychological assessment

A detailed interview is conducted with the patient to gather information about his symptoms, their duration, intensity and impact on daily life. With the patient’s permission, a conversation can also be held with his relatives and friends.

Data is collected on the patient’s psychosocial background, it is specified whether the patient has blood relatives who suffer from OCD or another mental illness.

Yale-Brown Scale (Y-BOCS)

The most widely accepted screening tool for OCD is the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). This scale asks the patient to rate the following questions based on their severity:

Obsessions:

Time spent obsessing: How much time is taken up by intrusive thoughts?
Intervention: To what extent do obsessions interfere with normal functioning?
Distress: How much distress do obsessions cause?
Resistance: How hard does the individual try to resist obsessions?
Control: How much control does the individual have over the obsessions?

Compulsions:

Time spent in compulsions: How much time is taken up by compulsions?
Intervention: How much do compulsions interfere with normal functioning?
Distress: How much distress do compulsions cause?
Resistance: How hard does the individual try to resist compulsions?
Control: How much control does the individual have over the compulsive behavior?

Rating:

Each question is scored on a scale of 0 to 4, with higher scores indicating greater severity.

0 = no symptoms
1 = mild symptoms
2 = moderate symptoms
3 = severe symptoms
4 = extreme symptoms

The Y-BOCS total score ranges from 0 to 40, indicating symptom severity.

0-7: subclinical stage
8-15: mild symptoms
16-23: moderate symptoms
24-31: severe symptoms
32-40: very severe stage.

Obsessive Compulsive Disorder Inventory ( OCI )

The Obsessive-Compulsive Disorder Inventory (OCI) is another tool used to assess the presence and severity of OCD symptoms.

The revised version (OCI-R) is the most commonly used version because of its brevity.

Components of the OCI-R:

The OCI-R measures symptoms in six subscales, each of which corresponds to a different type of OCD symptomatology:

washing – concerns related to soiling and washing/cleaning behaviour.
checking – repeatedly checking things to prevent potential harm.
doubt/good faith – excessive doubts and concerns about correctness or mistakes.
arrangement – a need for symmetry, order and arrangement of objects in a certain way.
obsession – presence of unwanted, intrusive and disturbing thoughts.
hoarding – difficulty disposing of objects, resulting in clutter.

Rating:

Each OCI-R question is rated on a 5-point scale from 0 to 4:
0 = not at all
1 = a little
2 = moderately
3 = a lot
4 = extremely

The total score ranges from 0 to 72.

Physical examination

A physical examination is performed to rule out other conditions that may cause similar symptoms.

There is no specific blood test for OCD, but in some cases lab tests may be ordered to rule out other possible medical causes.

Differential diagnosis of OCD

During the interview, it is extremely important to distinguish OCD from other conditions with similar symptoms, such as: