Capacity refers to an assessment of an individual’s psychological abilities to form rational decisions, specifically the individual’s ability to understand, appreciate, and manipulate information, and form rational decisions. Capacity is determined by physician often (although not exclusively) by a psychiatrist, and not the judiciary. It is different from competency, which is a legal term referring to “having sufficient ability… possessing the requisite natural or legal qualifications” to engage in a given endeavor. The determination of incompetence is a judicial decision, i.e., decided by the court.
There are four key elements in documenting a decision about capacity: