SCID-D (Structured Clinical Interview for Dissociative Disorders – Revised)
The SCID-D is considered the gold-standard diagnostic tool for diagnosing dissociative disorders. This extensively field-tested semi-structured interview assists clinicians not only with finding a diagnosis, but also with mapping out a starting treatment plan for the patient. This interview distinguishes dissociative disorders from other psychiatric disorders to ensure the patient is in fact dealing with a dissociative disorder. It also determines the specific dissociative disorder(s) the individual patient is dealing with in order to form a diagnosis.
MID (Multidimensional Inventory of Dissociation)
This assesses both DID and OSDD and focuses on disordered (pathological) dissociation, ignoring more normal day-to-day dissociative experiences. The MID is intended for use only by mental health researchers and clinicians and is a 218 item clinician-administered client self-report measure. It is available in two separate versions, one for adults and one for adolescents. This test rules out non-dissociative disorders and disorders other than DID/OSDD and then distinguishes between DID and OSDD to diagnosis the client with the correct disorder.
DDIS (Dissociative Disorders Interview Schedule)
This is a structured interview that requires no specialized training for the clinician to carry out. Clinical diagnosis should not be made using the DDIS alone – it should be used in conjunction with another test or interview from this list to make a formal diagnosis. The DDIS is useful as it’s a very accessible tool which doesn’t require specialized training and is available for free to download online so clinicians have easy access to the test to be able to add to their diagnostic plan/assessment. It’s meant to be used as an educational service and a tool.
Screening Tools (these cannot give a definitive diagnosis)
SDQ-20 (Somatoform Dissociation Questionnaire)
The SDQ-20 is a self-report questionnaire that is designed to assess patients with a dissociative disorder. This questionnaire was developed with a sample of psych outpatients with suspected dissociative disorders from a 75-symptom item pool. These items were deemed by experts to be able to reflect instances of somatoform dissociation (somatoform refers to when mental symptoms cause physical symptoms – i.e. when someone with PTSD has a flashback and gets shooting pain in their back despite nothing in that moment happening to cause that pain, but the pain is related to what is happening in their flashback). There are 20 separate items (from the 75 previously mentioned) that determine whether the patient has a dissociative disorder. Data has regularly suggested that age and gender do not seem to influence the SDQ-20 scores of dissociative disorders, strengthening the test’s validity. That being said this test is not specific enough to individual disorders to be used alone to make a definitive diagnosis.
DES-II (Dissociative Experiences Scale, 2nd Revision)
This is a screening tool used to identify individuals who have a high degree of dissociation. It can be taken without the assistance of a clinician as a self-assessment tool, but any definitive diagnosis should be made by a qualified clinician after a clinical interview.
The DES-II measures a wide variety of dissociative experiences, including daily dissociation (non-disordered, i.e. daydreaming, highway hypnosis, etc), and problematic dissociation (disordered, i.e. Depersonalization Disorder, Dissociative Identity Disorder, etc). People with PTSD also tend to score highly on the DES-II. This is not a diagnostic tool, but rather an assessment tool for individuals to determine whether they might benefit from reaching out to a clinician for further guidance.
The DES-II is meant for those over 18, and can be downloaded here.
The Adolescent DES-II is meant for those under the age of 18, and can be downloaded here.