OPINION
On April 16, 1991, Mobil Oil Corp. (“Mobil”) filed a motion for leave to file a petition for writ of mandamus. On April 30, 1991, the real party in interest filed a response at the request of the Court.
*323 This is a negligence suit. 1 James Brind-za sustained head injuries from a fall on Mobil’s premises. After this suit was filed he was declared non compos mentis in an Orange County guardianship proceeding and his wife, Tracie, was appointed permanent guardian of his person and estate. Relator did not participate in the guardianship proceeding.
Mobil seeks a writ of mandamus “reversing the trial court’s denial of Mobil’s Motion to Compel Deposition of James R. Brindza, Order the deposition of James R. Brindza and render court costs ...” James R. Brindza was the injured party and the initial plaintiff.
Mobil argues that Brindza is neither insane nor a child and therefore not within the classification of incompetent witnesses contained in Tex.R.Civ.Evid. 601. Brindza is a real party in interest — plaintiff in this suit and possesses information reasonably calculated to lead to discovery of admissible evidence, such as his present ability to function on a daily basis, his educational background, his training as an electrician, and his perceptions regarding on-the-job safety. He may, indeed, be the only witness to certain important and crucial, factual allegations.
A party to a suit has the right to depose the opposing party. Tex.R.Civ.P. 200(1). In practical realism, James R. Brindza is an opposing party and subject to the clear language and wording of Tex.R.Civ.P. 200(1). Mobil argues that it is the plaintiffs’ burden to show James Brindza is not competent to give his deposition, citing a criminal case,
Saucier v. State,
The deposition of Dr. Larry Pollock, a neuropsychologist who has treated Brind-za, appears as Appendix Exhibit 5. Mobil cites portions of the deposition where Dr. Pollock states that Brindza has normal memory and intelligence. In Pollock’s opinion, Brindza could answer questions such as whether his neck hurts or what kind of training he has. He has the ability to understand simple questions and give answers and he does have some useful memory. He has the ability to understand and give an oath to tell the truth. However, his understanding of his neuroeogni-tive and emotional functions is extremely poor. Mobil argues that none of the three factors in Handel, supra, are present here. Brindza was competent at the time of his training and the accident and he can pres *324 ently recall and communicate the pertinent events. He can understand the oath.
A real party in interest emphasizes other portions of Dr. Pollock’s deposition in support of its position that the allegations constitute a collateral attack on the Orange County judgment. A judgment of incompetency cannot be collaterally attacked.
Walker v. Robinson,
The general rule is discussed in several cases concerning whether a person is insane. Adjudication of insanity creates a rebuttable presumption of insanity which may be conclusively removed only by judgment of restoration of sanity.
Elliott v. Elliott,
We conclude that the fact of the guardianship does not automatically render Mr. Brindza incompetent to testify or incapable of giving his deposition. It does create a presumption that he is incompetent. The actual question then becomes whether he is capable of being deposed. We think it is necessary to view a discovery matter in a different light from the question of admissibility at trial because of their disparate natures and purposes. From the deposition testimony of the treating neuropsychologist, it appears that Mr. Brindza is capable of understanding the oath, and can recall and narrate events. This being so it results in Mobil being able to examine him under oath for discovery purposes although such testimony may or may not be admissible at trial.
Mandamus is a proper remedy for the improper denial of discovery.
Jampole v. Touchy,
We are persuaded that Judge Floyd will lift and vacate his order denying Mobil’s motion to compel the appearance of James R. Brindza (an original plaintiff) and the taking of his deposition. Hence, we grant the Writ of Mandamus conditionally. If, *325 however, the trial court fails to timely comply with this opinion, then the Writ of Mandamus will issue fully and unconditionally.
WRIT GRANTED CONDITIONALLY.
Notes
. Justice Brookshire wrote an opinion which reversed and remanded a companion case,
Brindza v. Mobil Oil Corp.,
