Okla. Stat. tit. 44, § 876B

ARTICLE 76B. Lack of mental capacity or mental responsibility. A. No person accused of violating a punitive section under the Oklahoma Uniform Code of Military Justice shall be brought to trial by a general or special court-martial if that person is presently suffering from a mental disease or defect rendering him or her mentally incompetent to the extent that he or she is unable to understand the nature of the proceedings against him or her or to conduct or cooperate intelligently in the defense of the case. B. A person is presumed to have the capacity to stand trial unless the contrary is established. C. The procedure for determining mental competence shall be established in regulations promulgated by the Adjutant General.