E. The disturbance is not better explained by another mental disorder, such as schizo- phrenia, panic disorder, major depressive disorder. acute stress disorder, posttrau- matic stress disorder, or another dissociative disorder.
The essential features of depersonalization/derealization disorder are persistent or recur- rent episodes of depersonalization, derealization, or both. Episodes of depersonalization are characterized by a feeling of unreality or detachment from, or unfamiliarity with, one’s whole self or from aspects of the self (Criterion A1). The individual may feel detached from his or her entire being (e.g., ”I am no one,” ”I have no self”). He or she may also feel subjectively detached from aspects of the self, including feelings (e.g., hypoemotionality: ”I know I have feelings but I don’t feel them"), thoughts (e.g., ”My thoughts don’t feel like my own,” ”head\filled with cotton”), whole body or body parts, or sensations (e.g., touch, proprioception, hunger, thirst, libido). There may also be a diminished sense of agency (e.g., feeling robotic, like an automaton; lacking control of one’s speech or movements).
The depersonalization experience can sometimes be one of a split self, with one part ob- serving and one participating, known as an ”out-of—body experience" in its most extreme form. The unitary symptom of ”depersonalization” consists of several symptom factors: anomalous body experiences (i.e., unreality of the self and perceptual alterations); emo- tional or physical numbing; and temporal distortions with anomalous subjective recall.
Episodes of derealization are characterized by a feeling of unreality or detachment from, or unfamiliarity with, the world, be it individuals, inanimate objects, or all surround- ings (Criterion A2). The individual may feel as if he or she were in a fog, dream, or bubble, or as if there were a veil or a glass wall between the individual and world around. Surround- ings may be experienced as artificial, colorless, or lifeless. Derealization is commonly ac- companied by subjective visual distortions, such as blurriness, heightened acuity, widened or narrowed visual field, two-dimensionality or ﬂatness, exaggerated three-dimensional- ity, or altered distance or size of objects (i.e., macropsia or rnicropsia). Auditory distortions can also occur, whereby voices or sounds are muted or heightened. In addition, Criterion
C requires the presence of clinically significant distress or impairment in social, occupa- tional, or other important areas of functioning, and Criteria D and E describe exclusionary diagnoses.
Individuals with depersonalization/derealization disorder may have difficulty describ- ing their symptoms and may think they are ”crazy” or “going crazy”. Another common experience is the fear of irreversible brain damage. A commonly associated symptom is a subjectively altered sense of time (i.e., too fast or too slow), as well as a subjective difficulty in vividly recalling past memories and owning them as personal and emotional. Vague so— matic symptoms, such as head fullness, tingling, or lightheadedness, are not uncommon.
Individuals may suffer extreme rumination or obsessional preoccupation (e.g., constantly obsessing about whether they really exist, or checking their perceptions to determine whether they appear real). Varying degrees of anxiety and depression are also common as- sociated features. Individuals with the disorder have been found to have physiological hyporeactivity to emotional stimuli. Neural substrates of interest include the hypotha- lamic-pituitary-adrenocortical axis, inferior parietal lobule, and prefrontal cortical-lirnbic circuits.