Hagerstown Mayor Donald Frush has been a voluntary patient in a psychiatric unit at Johns Hopkins University hospital since last Thursday, the mayor's brother said yesterday.

"I recommended it," said Calvin Frush of Hagerstown in a telephone interview. "In my conversations with him, I felt there was too much stress for him to deal with and he was running away from it. He went in on his own, for his own good."

Hospital spokeswoman Joann Rodgers, while acknowledging that Donald Frush is a patient, would not comment yesterday on his condition or eventual release.

Calvin Frush said his brother, a Republican, "still wants to be mayor," but has made no decision on whether he will withdraw from the March 26 municipal election against Democratic challenger Steve Sager. Frush said he is also uncertain about how long the mayor will remain hospitalized.

The announcement ended several days of speculation and bewilderment among Hagerstown residents, City Hall workers and even members of Frush's reelection campaign committee who did not know where the mayor had gone.

Frush, 54, who had reportedly behaved erratically in recent weeks, was last seen at City Hall on Feb. 25. On Monday, The Morning Herald of Hagerstown ran an article about the "missing mayor" and the case subsequently attracted media coverage from Atlanta to New York.

Campaign workers released a statement Wednesday that said the mayor was under a doctor's care for stress and fatigue resulting from pressures of his office and his reelection campaign, but gave no further details.

Calvin Frush said yesterday that his brother's hospitalization was kept secret because "Donald did not need to be hounded by the press." But LeRoy Metz, the mayor's campaign chairman, said media coverage might have been kept to a minimum if the matter had been handled differently. Both he and City Hall spokeswoman Judy Chambers said they only learned of the mayor's whereabouts yesterday.

"Everything was kept secret from us and we had to go on what little we had," Metz said yesterday. "That put everybody in an awkward position."