Dissociative Identity Disorder has been documented for centuries, although it was not always understood or labeled correctly. One of the earliest recorded cases dates back to 1584, involving Jeanne Fery. At the time, her symptoms were interpreted as possession, but historical records describe clear signs of what would now be recognized as DID, including multiple identity states, memory gaps, self-harm behaviors, and trauma history.

In the 1600s, similar cases, such as Sister Benedetta, were also described as possession rather than mental illness. For many years, DID was misunderstood as spiritual or supernatural phenomena.

By the 1800s, the disorder began to be recognized more medically. In 1882, Louis Vivet became the first person officially diagnosed with multiple personality disorder. His case included distinct personality states, amnesia between episodes, and changes in physical abilities and behavior. However, even then, clinicians often tried to fit cases into the more accepted “double personality” framework instead of recognizing multiple identities.

In the early 1900s, DID was grouped under hysteria in early psychiatric manuals. Around the same time, the diagnosis of schizophrenia became popular, and many individuals who likely had DID were instead diagnosed with schizophrenia because its early definition included multiple personalities. As a result, DID diagnoses declined significantly.

In the 1930s, dissociation was linked to childhood trauma, but these ideas were largely ignored for decades. Interest in dissociation returned after the recognition of posttraumatic stress disorder (PTSD) in trauma survivors, which helped shift attention back to trauma-related conditions.

In the 1970s, the case of Sybil brought DID into popular culture, leading to a dramatic increase in reported cases. However, this also sparked controversy about whether some cases were influenced by media or therapeutic suggestion.

Today, DID is officially recognized in the DSM-5-TR as a dissociative disorder. Although debate still exists, modern understanding strongly connects DID to severe childhood trauma and dissociation as a coping mechanism.