In psychology and mental health, the host is the most prominent personality, state, or identity in someone who has dissociative identity disorder (DID) (formerly known as multiple personality disorder). The host may or may not be the original personality, which is the personality a person is born with.
Prevalence
In some very mild forms of DID, the host can be present for extended periods of time, up to years without ever allowing an alter to take the forefront. In these cases, the host is very resilient to stress and other factors that often cause switches.
In severe cases, there is often large amounts of switching and the person may not spend that much time in any state, including the host. In cases where the host is often present, there are a few triggers that can cause the host to retreat.
Treatment
The host is often the personality that seeks treatment. In some cases, the host is unaware of any alters or even that they have DID. In other cases, the host is aware of their condition, but they may not be aware of what the alters are or what they do while in those states. There are situations where the host wants therapy; however, one or more of the alters does not and can try to end the therapeutic process. The host often shows higher EEG coherence than alter personalities. Since the host may not use the official name of the person, there can be disputes on which identities are responsible for an action.