Do psychiatric patients need greater protection than medical patients when they consent to treatment?

It is commonly assumed that psychiatric patients require greater protection than medical patients when they make health care decisions. A review of the literature reveals that there is meager evidence for this belief and that both groups have significant capacity problems. Many factors other than psychiatric illness have been shown to impede understanding of informed consent information in health care settings. These include powerful emotional states, lack of a high school education, the presence of a severe medical illness, and increasing age. Clinicians can help patients become more adequate decision makers by taking such steps as providing adequate disclosure and inquiring about patient understanding. Even then, setting a realistically lenient standard of capacity seems the most practical approach. If screening for capacity is important for a specific health care decision, all vulnerable groups should be targeted.