Depersonalization Disorder - Diagnosis

Diagnosis

Diagnosis is based on the self-reported experiences of the person followed by a clinical assessment by a psychiatrist, clinical social worker, clinical psychologist or other mental health professional. Psychiatric assessment includes a psychiatric history and some form of mental status examination. Since some medical and psychiatric conditions mimic the symptoms of DPD, clinicians must differentiate between and rule out the following to establish a precise diagnosis: temporal lobe epilepsy, panic disorder, acute stress disorder, schizophrenia, migraine, drug use, brain tumour or lesion. Anxiety has also been shown to be a key factor in triggering symptoms of depersonalization disorder. In a study conducted by Maurico Sierra and the Depersonalization Research Unit of King’s College London, the results suggest that anxiety only contributes to the intensity of the episodes of depersonalization in those experiencing low to mild depersonalization. No laboratory test for depersonalization disorder currently exists.

The diagnosis of DPD can be made with the use of the following interviews and scales:

The Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) is widely used, especially in research settings. This interview takes about 30 minutes to 1.5 hours, depending on individual's experiences.

The Dissociative Experiences Scale (DES) is a simple, quick, self-administered questionnaire that has been widely used to measure dissociative symptoms. It has been used in hundreds of dissociative studies, and can detect depersonalization and derealization experiences.

The Dissociative Disorders Interview Schedule (DDIS) is a highly structured interview which makes DSM-IV diagnoses of somatization disorder, borderline personality disorder and major depressive disorder, as well as all the dissociative disorders. It inquires about positive symptoms of schizophrenia, secondary features of dissociative identity disorder, extrasensory experiences, substance 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 patients may suffer from. It has been proven and accepted as a valid tool for the diagnosis of depersonalization disorder in a clinical setting. It was validated through trials with a sample of patients who had been confirmed to be suffering from depersonalization disorder. It is also used in a clinical setting to differentiate minor episodes of depersonalization from suffering 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 it’s accuracy. They did discover a limitation that the scale did not allow for the differentiation between past and present episodes of depersonalization. It should also be noted that it may be difficult for the patient to describe the duration of depersonalization episodes and thus the scale lacks some degree of accuracy. The project was conducted in the hope that it would stimulate further scientific investigations into depersonalization disorder.