Dissociative Disorders
Dissociative disorders are characterized by an individual becoming split off, or dissociated, from her core sense of self. Memory and identity become disturbed; these disturbances have a psychological rather than physical cause.
The DSM-5 lists several dissociative disorders, including dissociative amnesia, depersonalization/derealization disorder, and dissociative identity disorder.
dissociative amnesia
Amnesia refers to partial or total forgetting of some experience or event. In dissociative amnesia, a person is unable to recall important personal information, usually following an extremely stressful or traumatic experience such as combat, natural disasters, or being a victim of violence. Unlike ordinary forgetfulness, this memory loss is extensive and cannot be explained by normal memory processes.
Some individuals with dissociative amnesia also experience dissociative fugue (from the French word meaning “to flee”). In these episodes, a person suddenly wanders away from home, experiences confusion about their identity, and sometimes even adopts a new identity (Cardeña & Gleaves, 2006). Most fugue episodes last only hours or days, though some continue longer.
depersonalization/derealization disorder
Depersonalization/derealization disorder involves recurring episodes of depersonalization, derealization, or both—while reality testing remains intact (the person knows their experiences are unusual).
Depersonalization involves feelings of unreality or detachment from one’s self (APA). People experiencing depersonalization might:
- Feel their thoughts and feelings aren’t their own
- Feel robotic, as if lacking control over movements and speech
- Experience a distorted sense of time
- In extreme cases, have “out-of-body” experiences, viewing themselves from another person’s perspective
Derealization involves a sense of unreality about the surrounding world (APA). A person might:
- Feel as though they’re in a fog or dream
- Perceive the environment as artificial or unreal
- See surroundings as visually distorted, flat, or colorless
Individuals with this disorder often have difficulty describing their symptoms and may fear they’re “going crazy.”
Prevalence
A 2023 systematic review found that the prevalence of depersonalization/derealization disorder is approximately 1% in the general population (Yang et al., 2023). However, transient depersonalization experiences are much more common—between 26-74% of people experience brief episodes at some point in their lives, often triggered by fatigue, stress, or traumatic events.
The disorder is more prevalent among adolescents and young adults, with 80% or more experiencing their first symptoms before age 20. Notably, the highest rates (25-54%) are found in people who have experienced interpersonal abuse, highlighting the connection between trauma and dissociative experiences.
dissociative identity disorder
Dissociative identity disorder (DID)—formerly called multiple personality disorder—is the most well-known and most severe dissociative disorder. People with DID exhibit two or more distinct personality states or identities, each with its own pattern of perceiving and relating to the world.
People with DID experience:
- Multiple identities: Two or more distinct personality states, sometimes called “alters”
- Amnesia: Memory gaps for time when another identity is in control (e.g., finding unfamiliar items among possessions, being told about actions they don’t remember)
- Auditory experiences: Some report hearing voices, such as a child’s voice or someone crying
- Depersonalization and derealization: Persistent experiences of detachment
A community study found that approximately 1.5% of participants experienced symptoms consistent with DID in the previous year (Johnson et al., 2006).
Why DID Is Controversial
DID remains one of the most debated diagnoses in psychiatry for several reasons.
Concerns about malingering. Some argue that people fake DID symptoms to avoid consequences for illegal actions. The case of Kenneth Bianchi illustrates this concern. Bianchi, who murdered over a dozen women in Los Angeles in the late 1970s, initially pled not guilty by reason of insanity, claiming a different personality (“Steve Walker”) committed the murders. When experts scrutinized his claims, he admitted to faking and was found guilty (Schwartz, 1981).
Historical fluctuation in diagnosis rates. More DID cases were identified in the five years before 1986 than in the preceding two centuries (Putnam et al., 1986). This dramatic increase coincided with the popularization of DID through Sybil (1973), a book and later film about a woman with 16 personalities. Some researchers argue this led clinicians to overdiagnose the condition. Recent investigations have also suggested the Sybil case itself was largely fabricated (Nathan, 2011).
Two competing models. The debate continues between two theoretical explanations:
- The trauma model proposes that DID develops as a coping mechanism in response to severe childhood trauma, with dissociation serving as a survival strategy
- The sociocognitive model suggests DID may result from social influences, suggestive therapy, or cultural expectations—essentially learned behavior rather than a distinct disorder
Evidence Supporting DID as a Legitimate Disorder
Despite controversy, substantial evidence supports DID as a real and serious condition:
- Trauma histories. Research consistently shows that people with DID report extremely high rates of childhood trauma. Ross et al. (1990) found approximately 95% reported physical and/or sexual abuse as children. While not all abuse reports can be independently verified, many cases have been corroborated through medical or legal records (Cardeña & Gleaves, 2006).
- Neurobiological findings. Brain imaging studies reveal that patients with DID show structural differences compared to healthy controls, including smaller amygdala and hippocampal volumes—brain regions involved in emotion processing and memory (Young, 2024). These findings are difficult to explain through malingering or suggestion alone.
- Current scientific consensus. A 2024 review in the American Journal of Psychotherapy described DID as a “posttraumatic, psychobiological syndrome that develops over time during childhood” and emphasized that despite historical controversy, empirical evidence now supports both the validity of the diagnosis and its relationship to trauma (Robinson et al., 2024). Expert consensus guidelines recognize DID as a treatable condition.
- Dissociation as a coping mechanism. Strong evidence demonstrates that traumatic experiences can trigger dissociative states. Dissociation—including the development of distinct identities—may serve as a psychologically protective mechanism that helps individuals cope with overwhelming threat and danger (Dalenberg et al., 2012).