22nd February 2024

Diagnosis

The presentation of OCD overlaps with other psychiatric disorders, such as anxiety and depressive disorders, making diagnosis difficult. On average, it takes 9 years before OCD is correctly diagnosed, with around 17 years between the first onset of symptoms and appropriate treatment.  Patients are often embarrassed and avoid reporting their symptoms. In some cases, they present to health care professionals due to a medical condition which has resulted from their OCD e.g. dermatitis caused by excessive hand washing. 

ICD-10 for OCD diagnosis requires there to be recurrent obsessional thoughts or compulsive actions.

Differentials 

OCD is very similar to anankastic personality disorder. This is where individuals have rigid ways of doing things and have high standards of hygiene and cleanliness, which is often confused with OCD. However, the key difference is the lack of compulsive and repetitive behaviour.

Investigation

• Structured clinical interview for the DSM (SCID-5). This SCID-5 is derived from the DSM-5 and is a tool used to assess whether a patient meets the DSM-5 criteria for OCD. This tool is commonly used in research settings. 
• Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). This is not a diagnostic tool but is used to determine the severity of OCD symptoms. It should be used at the start and during treatment to assess progress. 
• Clinical global impression (CGI)