Obtaining informed consent from a 45-year-old woman with dissociative identity disorder

To the Editor

Dissociative identity disorder (DID) is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV-TR as the presence of two or more distinct identities or personality states in one individual, with at least two of these identities recurrently taking control of the person’s behavior (American Psychiatric Association, 2000). There is usually a primary identity and one or several other alternate identities or ‘alters’ (Gillig, 2009). By all accounts, DID is a relatively rare disorder (Sadock et al., 2009) and the diagnosis is not without controversy (Gillig, 2009; Sadock et al., 2009). The actual validity of the diagnosis is beyond the scope of this paper. Our aim is to discuss consulting questions regarding a patient previously diagnosed with DID who presented to the surgical service at our hospital.

The patient, a 45-year-old Caucasian female, was transferred from a peripheral hospital to the university teaching hospital for the treatment of colitis. Liaison psychiatry was consulted when the patient told the surgery team about her previous diagnosis of DID and the presence of six separate identities. The surgical team’s main questions for consultation were: (1) does the patient have the ability to consent for medical treatment? and (2) is consent by the primary identity sufficient? Before the patient could be evaluated, the patient left the hospital against medical advice (AMA).

Capacity to consent is based on a patient’s understanding of the risks, benefits, and alternatives to treatment (Glezer et al., 2011). The decision needs to be free from coercion, whether from a family member or friend, or from the effects of a medical or mental illness. An example of the latter would be a patient who has dementia and does not have the cognitive abilities to understand the risks, benefits, or alternatives. In such cases, a surrogate decision-maker would need to be established. In this particular case, does the DID meet the threshold of coercion of the patient’s ability to make an informed, autonomous decision? In this case, it would have to be determined whether or not a coercive process was affecting the primary identity’s ability to consent.

The second question is whether consent from the primary identity (assuming capacity) is sufficient. Dorahy (2001) reviewed the literature and concluded that there are several possibilities of awareness between the various identities: (1) mutual awareness; (2) one-way amnesia (asymmetric amnesia), in which the alters are aware of the primary but not vice-versa; and (3) two-way amnesia (symmetric amnesia), in which none of the identities are aware of the others (Dorahy, 2001). Asymmetric amnesia is traditionally thought of as the most common (Dorahy, 2001). This reformulates the question as: ‘can the primary identity consent if she is unaware of the other identities and their wishes?’

A final question to consider would be the conundrum of how to proceed if one or more alters disagrees with one another or the primary identity. A literature search revealed no published guidance regarding these issues. Further research on DID regarding legal matters of capacity, competence, and decision-making is needed.