Mental Status Exam in “The Psychiatric Interview for Differential Diagnosis” by Jansson & Nordgaard of Denmark does not screen for dissociative identity.

The reason that most clinicians in the USA and around the world think they have never seen a case of multiple personality (dissociative identity) is that they evaluate memory like this new textbook from Denmark:

“Memory can be divided into short-term and long-term memory…Memory disturbances can be separated into those that are psychogenic (also occurring in healthy people) and those that are of organic origin. The amnestic syndrome, a disorder characterized by systematic and extensive loss of long-term memory, can be caused by head injury, alcohol, drugs, or other organic noxae…Psychogenic amnesia is a sudden amnesia occurring during periods of extreme psychotrauma…” (1, p. 85).

The above fails to ask the basic screening question for multiple personality:

Have you ever had memory gaps (not caused by head injury, alcohol, drugs, or other organic causes)? This one little question is all that most clinicians need add to their routine mental state evaluation.

If the answer to the above is positive, you might ask: Does anything ever happen that nobody else could have done, but you don’t remember doing it? Are there any significant events (weddings, sexual encounters, etc.) that you don’t remember, or have less memory of than you would expect to have? Do you ever find things in your possession (clothing, writing, etc.) that you can’t account for? Have you ever found yourself somewhere, but didn’t remember how you got there? Do people ever refer to things (conversations, etc.) that they assume you recall, but you don’t? Have you ever been accused of doing things that you didn't recall doing (and if you denied it, they thought you were a liar)?

I should mention that even if you ask all these questions, you will still miss at least a third of patients with multiple personality, because many multiples are quite bright, will guess what you are asking about, and purposely answer with a false negative. Why? Because alternate personalities think it’s none of your business, and host personalities fear it.

For further discussion, search “mental status” and “memory gaps.”

1. Lennart Jansson, Julie Nordgaard. The Psychiatric Interview for Differential Diagnosis. Switzerland, Springer, 2016.