“As an undergraduate student in psychology, I was taught that multiple personalities were a very rare and bizarre disorder. That is all that I was taught on ... It soon became apparent that what I had been taught was simply not true. Not only was I meeting people with multiplicity; these individuals entering my life were normal human beings with much to offer. They were simply people who had endured more than their share of pain in this life and were struggling to make sense of it.”
― Deborah Bray Haddock, The Dissociative Identity Disorder Sourcebook
The DSM-5 gives the following criteria for a diagnosis of depersonalization/derealization disorder:
A. The presence of persistent or recurrent experiences of depersonalization, derealization, or both:
1. Depersonalization: Experiences of unreality, detachment, or being an outside observer with respect to one’s thoughts, feelings, sensations, body, or actions (e.g., perceptual alterations, distorted sense of time, unreal or absent self, emotional and/or physical numbing).
2. Derealization: Experiences of unreality or detachment with respect to surroundings (e.g., individuals or objects are experienced as unreal, dreamlike, foggy, lifeless, or visually distorted).
B. During the depersonalization or derealization experiences, reality testing remains intact.
C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
D. The disturbance is not attributable to the physiological effects of a substance (e.g., a drug of abuse, medication) or another medical condition (e.g., seizures).
E. The disturbance is not better explained by another mental disorder, such as schizophrenia, panic disorder, major depressive disorder, acute stress disorder, posttraumatic stress disorder, or another dissociative disorder (American Psychiatric Association, 2013)1.
Criterion A clarifies that depersonalization/derealization disorder involves feelings of depersonalization (such as that one isn't real or isn't connected to or in control of one's thoughts, feelings, sensations, body, or actions; this may involve alterations in how one perceives reality, how one experiences time, how one conceptualizes their ida of self, or how one experiences emotions or physical sensations) and/or feelings of derealization (such as that the world around one isn't real or relevant to them; this may involve the world seeming unreal, dreamlike, foggy, lifeless, or distorted).
Individuals experiencing depersonalization may feel that they have no identity, be able to recognize but not experience emotions, experience their thoughts as alien and not their own, feel disconnected from their whole body or specific parts of their body, or be unable to register or comprehend sensations such as touch, hunger, or thirst. They may feel robotic and out of control, or they may have an "out of body experience" in which they feel as if they are witnessing their own actions as a passive observer.
Individuals experiencing derealization may feel that the world, individuals, inanimate objects, or all surroundings are unreal, unfamiliar, or detached. They may feel as if they are in a dream, fog, or bubble or as if they are separated from the world around them by glass or by a veil. The world around them may appear to be colorless, lifeless, or artificial, and other visual distortions regarding blurriness, visual field, flatness, or distance may be present. Auditory distortions may cause voices to be perceived as either muted or sharpened.
Criterion B specifies that the depersonalization or derealization is not due to psychosis. The individual experiencing depersonalization or derealization is capable of understanding that their experiences are not objectively true. However, the individual may not understand the cause of their experiences and so attribute them to "going crazy" or possible brain damage.
Criterion C excludes occasional feelings of unreality or perceptual alterations that are not distressing or dysfunctional. Transient episodes of depersonalization or derealization that last hours to days are common in the general population, but only 0.8% to 2.8% of people worldwide actually meet the criteria for the disorder.
Criterion D excludes depersonalization and derealization that are caused by substance use, substance withdrawal, or seizures. However, some illicit substances can trigger depersonalization/derealization disorder that lasts for a significant amount of time in the absence of further substance use. If onset of symptoms begins after age 40, an underlying medical condition should be considered. Depersonalization/derealization disorder usually starts during one's teenage years, though it can begin in early or middle childhood. It rarely begins so early that one cannot remember life without it or after one has turned 25. Onset after age 40 is very unusual.
Criterion E excludes depersonalization and derealization that are caused by another mental disorder. Anxiety disorders are often co-morbid with depersonalization/derealization disorder or contain dissociative features, but the latter is not an example of depersonalization/derealization disorder. Episodes of depersonalization or derealization that occur only during panic attacks should be considered to be aspects of an anxiety disorder. Emotional numbing, apathy, and unreality due to major depressive disorder do not warrant a diagnosis of depersonalization/derealization disorder. In the absence of reality testing, a psychotic disorder should be diagnosed. If depersonalization/derealization symptoms occur in the context of another dissociative disorder, that diagnosis takes precedent (for example, an individual with dissociative identity disorder who has episodes of derealization would only be diagnosed with DID, though an individual can be diagnosed with both dissociative amnesia and depersonalization/derealization disorder as those disorders contain no overlap in symptoms).
Onset can be sudden or gradual, and episodes can last from hours to years. Stress or environmental factors can trigger episodes or exacerbate symptoms. Though childhood trauma is associated with depersonalization/derealization disorder, this connection is not as strong as it is for other dissociative disorders. The disorder is often associated with severe stress, depression, anxiety, and substance abuse (American Psychiatric Association, 2013)1. There is also evidence that meditation can trigger depersonalization or derealization (Lustyk, Chawla, Nolan, & Marlatt, 2009).2
1 American Psychiatric Association. (2013). Dissociative Disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). http://dx.doi.org/10.1176/appi.books.9780890425596.dsm08
2 Lustyk, M. K. B., Chawla, N., Nolan, R. S., & Marlatt, A. (2009). Mindfulness meditation research: Issues of participant screening, safety procedures, and researcher training. Advances in Mind Body Medicine , 24(1), 20-30.