CONCORD, N.H. — In an e-mail written from a treatment center, the Episcopal Church's first openly gay bishop, V. Gene Robinson, said he is receiving treatment for alcoholism.

For years, Robinson said in the e-mail sent to clergy, he considered it "a failure of will or discipline on my part, rather than a disease over which my particular body simply has no control, except to stop drinking altogether."

The news, made public Tuesday, caught many Episcopalians by surprise. Robinson, 58, said he checked into the undisclosed center Feb. 1 with the support of his partner, daughters and colleagues.

"I never saw it in any way impact his ministry in the diocese," said Robinson's assistant, the Rev. Tim Rich.

Robinson was his predecessor's top assistant for years and was elected to replace him when he retired in 2003 by clergy and lay people in the diocese. He was confirmed by the national church, causing an upheaval not only in the Episcopal Church, but the worldwide Anglican Communion of which it is part.

David Virtue of West Chester, who opposed Robinson's election and runs an online news service he describes as a global voice for orthodox Anglicans, said Robinson should have revealed his problem earlier.

"Why now? Why didn't we know this (then)?" he said. "What happened to the discernment process?"

Other critics, though, reacted differently. "I'm glad he's getting help. None of us are perfect," said Lisa Ball, who opposed Robinson's selection and was part of a group in Rochester that broke away from the diocese and started a new church.

The Rev. David Jones, who co-chaired the bishop search committee, said thorough background checks were performed on all the candidates for bishop, including criminal checks and interviews with former employers and others. Finalists also were asked if there was anything in their past that would embarrass them or the diocese if it came to light and Robinson did not say he was an alcoholic, Jones said.

"For all I know, at that point, he didn't have a problem," Jones said.