In Reply: Dr. Varma raises questions about the cognitive capacity of patients with serious mental illnesses and its impact on their ability to complete advance directives. Because many lay people assume that psychiatric disorders render all patients incompetent, it may be worth emphasizing several points in response to Dr. Varma's letter.
First, advance directive statutes typically create a legal presumption that persons completing the forms were competent to do so, requiring affirmative evidence of incompetence to invalidate their directives. This comports with the usual legal maxim that all adults are presumed competent unless proven otherwise.
Second, although the cognitive impairments associated with serious mental illnesses may impair patients' decisional capacities, subtle deficits are insufficient to render someone incompetent. Because in a democratic society we desire to maximize the number of people who can make decisions for themselves, the threshold for declaring someone incompetent is a high one; even many patients hospitalized with acute psychoses or depression remain competent to make decisions about their treatment (1).
Finally, the published data on patients' capacities to write psychiatric advance directives, although limited at this point, suggests that even patients with serious mental disorders are generally quite capable of performing this task (2). Anecdotal reports from other researchers appear to confirm these data. Although there may be a role for formal instruments to assess competence in a small number of cases, concerns about patients' capacities ought not to be a major barrier to more widespread use of advance directives for psychiatric treatment and end-of-life care.
Editor's Note: Dr. Appelbaum's Taking Issue piece in the May issue discussed the role of stigma in the promotion of advance directives among persons with serious mental illness (3).