Diagnosis of Depersonalization / Derealization Disorder Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) criteria Medical and psychiatric examination to rule out other causes Diagnosis of depersonalization / derealization disorder is clinical, based on the presence of the following criteria in the DSM-5-TR: Patients have persistent or recurrent episodes of depersonalization, derealization, or both.