Petitioner seeks review of a final order of the Psychiatric Security Review Board (PSRB) ordering that he continue under its jurisdiction. We reverse and remand.
On April 5, 1990, petitioner was found guilty except for insanity1 of three felonies and two misdemeanors. As a result, he was placed under the jurisdiction of PSRB and committed to the Oregon State Hospital.2 On June 22, 1990, he had an initial hearing before PSRB, ORS 161.341(7)(a), which found that petitioner is affected by a mental disease or defect and ordered that his commitment be continued.
Petitioner contends that there is not substantial evidence to support PSRB’s finding that he is affected by a mental disease or defect. PSRB argues that, because petitioner did not “formally apply, pursuant to ORS 161.341(4), to PSRB for an order of discharge or conditional release,” it was not required at the initial hearing to make a finding that petitioner is affected by a mental disease or defect. PSRB maintains that, pursuant to ORS 161.341(1), it is required only to determine at an initial hearing that
“the person presents a substantial danger to others and is not a proper subject for conditional release.” (Emphasis supplied.)
ORS 161.341(7)(a) provides:
“In no case shall any person committed by the court under ORS 161.327 to a state hospital * * * be held in the *583hospital for more than 90 days from the date of the court’s commitment order without an initial hearing before the board to determine whether the person should be conditionally released or discharged.”
ORS 161.341(7)(a) does not specifically require the finding of mental disease or defect. It does require that an initial hearing be held and that PSRB determine whether to discharge or conditionally release the person. ORS 161.351(1) provides:
“Any person placed under the jurisdiction of the Psychiatric Security Review Board pursuant to ORS 161.336 or 161.341 shall be discharged at such time that the board, upon a hearing, shall find by a preponderance of the evidence that the person is no longer affected by a mental disease or defect or, if so affected, no longer presents substantial danger to others which requires regular medical care, medication, supervision or treatment.” (Emphasis supplied.)
The finding of mental disease or defect is required at the initial hearing, because PSRB is required at that hearing to determine if a person under its jurisdiction may be discharged, which requires a finding of whether the person is affected by a mental disease or defect.3 See Martin v. PSRB, 103 Or App 385, 797 P2d 401 (1990), rev’d on other grounds 312 Or 157, 818 P2d 1264 (1991).
PSRB found:
“[Petitioner] is affected by a mental disease or defect as demonstrated by the underlying facts shown by the evidence, including the testimonies of Terrance Lally, Ph.D., and John E. Meyer, M.D., as well as Dr. Meyer’s report as found in Exhibits 10 and 12, and the report of Dr. Norman Janzer, M.D., as found in Exhibit 9.”
The state introduced extensive evidence that petitioner had previously suffered from a mental disease or defect. The *584evidence consisted of a prior diagnosis made during a previous commitment in 1985, evidence concerning petitioner’s behavior during the criminal episode resulting in this commitment and evidence relating to petitioner’s mental state when the court placed him under the jurisdiction of PSRB. However, that evidence is not itself sufficient to prove petitioner’s mental state at the time of the hearing. The state’s only evidence concerning that is the testimony of Meyer and Lally. Meyer testified that petitioner suffers from “possible bipolar disorder, presently in remission.” (Emphasis supplied.) Lally was “leaning towards finding that [petitioner] is not suffering from a mental illness,” although, because of insufficient time to formulate a diagnosis, he was not able to rule out the “tentative diagnosis of schizoaffective disorder or manic depressive illness.” (Emphasis supplied.) The state’s evidence establishes, at best, only a possibility that petitioner is affected by a mental disease or defect, not that he is. PSRB’s finding that petitioner is affected by a mental disease or defect is not supported by substantial evidence. ORS 183.482(8)(c); Valleur v. Psychiatric Review Board, 43 Or App 843, 845, 604 P2d 439 (1979).
Reversed and remanded for proceedings not inconsistent with this opinion.
ORS 161.295(1) provides:
“A person is guilty except for insanity if, as a result of mental disease or defect at the time of engaging in criminal conduct, the person lacks substantial capacity either to appreciate the criminality of the conduct or to conform the conduct to the requirements of law.”
ORS 161.327(1) provides, in part:
“Following the entry of a judgment pursuant to ORS 161.319 and the dispositional determination under ORS 161.325, if the court finds that the person would have been guilty of a felony, or a misdemeanor during a criminal episode in the course of which the person caused physical injury or the risk of physical injury to another, and if the court finds by a preponderance of the evidence that the person is affected by mental disease or defect and presents a substantial danger to others requiring commitment to a state hospital designated by the Mental Health Division and Developmental Disability Services Division or conditional release, the court shall order the person placed under the jurisdiction of the Psychiatric Security Review Board for care and treatment.”
In any event, PSRB concedes that it is bound by OAR 859-60-015, which provides:
“After being placed under the jurisdiction of the Board and committed to a state hospital, the person shall have an initial hearing before the Board to determine whether the person should be committed, conditionally released or discharged:
“(1) At an initial hearing, the Board shall make a finding on the issue of presence of mental disease or defect and may base it on the court’s findings and any additional information received.” (Emphasis supplied.)