Psychological and legal aspects of mental incompetence.

The elderly population in the United States is increasing gradually. Estimates project that during the next 50 years 21% of the population, or approximately 70 million people, will be older than 65 years. Various medical and psychiatric disorders produce cognitive disturbances that result in temporary or permanent incompetence. That incompetence will affect an individual's decision-making capacity and ability to give informed consent. Problems exist related to obtaining informed consent from the elderly and distinguishing between incapacitated versus incompetent individuals. Physicians are responsible for providing information to their patients about a durable power of attorney for health care, a living will, and "do not resuscitate" orders, before they lose their capacity to make decisions related to their health care. Informed consent, living wills, durable power of attorney for health care, and guardianship are discussed.