The legal construct of competency to stand trial requires that a defendant has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding and a rational as well as factual understanding of the legal proceedings against him. The trier of fact (usually a judge) is responsible for interpreting what capacities are sufficient to meet the legal standard of trial competency. Mental health experts who assist the court in establishing whether or not a defendant is competent to proceed are in a position to explain how mental health issues factor in to a defendant's capacities in relation to the relevant legal concepts. There are three primary capacities that are relevant to a defendant's trial competency: general capacity, decisional capacity, and particular capacities in reference to a defendant's specific case. General capacities speak to a defendant's intrinsic abilities, including his level of psychiatric, intellectual, cognitive, and interpersonal functioning. Decisional capacities consider the manner in which a defendant makes everyday decisions and how this may impact his conceptualization of his case, the rationality of his legal decisions, and his ability to work with his attorney. Particular capacities speak to the unique elements of a defendant's legal case, requiring a direct analysis of relevant case facts and how these may interact with the defendant's mental status. Defendants who are found by the court to be incompetent to stand trial may be referred for competency restoration treatment, depending upon the guidelines of the particular jurisdiction. If treatment with psychiatric medications is required, a judicial hearing may be held to determine whether this treatment will meet established criterion to authorize involuntary treatment. Legal standards for competency to stand trial are the same as competency to be sentenced, to plead guilty, to waive an insanity defense, to waive privilege, to waive the right to counsel, and to be executed as each speaks to decisional capacities specific to a defendant's case. The decision to proceed
pro se
(represent self) also must be made voluntarily and intelligently.