abuse and other items relevant to the dissociative disorders. The DDIS can usually be administered in 30–45 minutes. The Cambridge Depersonalization Scale (CDS) is a method for determining the severity of depersonalization disorder. It has been proven and accepted as a valid tool for the diagnosis of depersonalization disorder in a clinical setting. It is also used in a clinical setting to differentiate minor episodes of depersonalization from actual symptoms of the disorder. Due to the success of the CDS, a group of Japanese researchers underwent the effort to translate the CDS into the J-CDS or the Japanese Cambridge Depersonalization Scale. Through clinical trials, the Japanese research team successfully tested their scale and determined its accuracy. One limitation is that the scale does not allow for the differentiation between past and present episodes of depersonalization. It may be difficult for the individual to describe the duration of a depersonalization episode, and thus the scale may lack accuracy. The project was conducted in the hope that it would stimulate further scientific investigations into depersonalization disorder. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) In the DSM-5, the word "derealization" was added to "depersonalization disorder" and renamed "depersonalization/derealization disorder" ("DPDR"). It remains classified as a dissociative disorder. Patients must meet the following criteria to be diagnosed per the DSM-5: Presence of persistent/recurrent episodes of depersonalization/derealization Ability to distinguish between reality and dissociation during an episode (i.e. patient is aware of a perceptual disturbance) Symptoms are severe enough to interfere with social, occupational, or other areas of functioning Symptoms are not due to a substance or medication Symptoms are not due to another psychiatric disorder International Classification of Diseases 11th Revision (ICD-11) The ICD-11 has relisted DPDR as a disorder rather than a syndrome as previously, and has also reclassified it as a dissociative disorder from its previous listing as a neurotic disorder. The description used in the ICD-11 is similar to the criteria found in the DSM-5. Individuals with DPDR are described as having persistent/recurrent symptoms of depersonalization/derealization, have intact reality testing, and symptoms are not better explained by another psychiatric/neural disorder, substance, medication, or head trauma. Symptoms are severe enough to cause distress or impairment in functioning. Differential diagnoses DPDR differentials include neurologic and psychiatric conditions as well as side effects from illicit substances or medications. Neurologic Seizures Brain tumor Post-concussion syndrome Metabolic abnormalities Migraines Vertigo Meniere's disease Psychiatric