In Dissociative Identity Disorder (DID), formerly known as Multiple Personality Disorder (MPD), a person may experience the presence of multiple distinct identities or personality states, which are often referred to as "alters" or "alternate personalities." The number of alters in a DID system can vary significantly from one individual to another.
Some individuals with DID may have only a few alters, while others may have numerous ones. The number can range from a handful to dozens, and in rare cases, even more than a hundred. The specific number of alters in a person's system can be influenced by various factors, including the severity and duration of trauma experienced, coping mechanisms developed during childhood, and individual differences in how dissociation manifests.
It's important to note that the experience of DID is complex and unique to each individual, and therapy with a mental health professional experienced in working with trauma and dissociation is essential for diagnosis and treatment.