New York ? The American Psychiatric Association has a hot potato on its hands as it updates its catalog of mental disorders — whether to include parental alienation, a disputed term conveying how a child’s relationship with one estranged parent can be poisoned by the other.

There’s broad agreement that this sometimes occurs, usually triggered by a divorce and child-custody dispute. But there’s bitter debate over whether the phenomenon should be formally classified as a mental health syndrome — a question now before the psychiatric association as it prepares the first complete revision since 1994 of its Diagnostic and Statistical Manual of Mental Disorders.

“We’re gotten an enormous amount of mail — more than any other issue,” said Dr. Darrel Regier, vice chair of the task force drafting the manual. “The passions on both sides of this are exceptional.”

On one side of the debate, which has raged since the 1980s, are feminists, advocates for battered women and others who consider “parental alienation syndrome” to be an unproven and potentially dangerous concept useful to men trying to deflect attention from their abusive behavior.

“This is a fabricated notion — there’s no science to support it,” said Joan Meier, a professor at the George Washington University Law School who has written extensively on domestic violence and child custody.

On the other side are legions of firm believers in the existence of a syndrome, including hundreds gathering for a conference on the topic this weekend in New York. They say that recognition of parental alienation in the psychiatrists’ manual would lead to fairer outcomes in family courts and enable more children of divorce to get treatment so they could reconcile with an estranged parent.

“This is a problem that causes horrible outcomes for children. … All the arguments I’ve heard against it are trivial,” said Dr. William Bernet, a psychiatry professor at the Vanderbilt University School of Medicine.

Bernet is among the speakers at this weekend’s conference, which organizers bill as the largest ever on parental alienation. He will be describing his efforts as lead author of the proposal submitted to the psychiatric association to recognize parental alienation either as a “mental disorder” or a “relational problem.”

The psychiatric association first published its manual of diagnostic disorders, known as the DSM, in 1952. The last major revision was published in 1994 and updated in 2000, and the fifth edition — DSM-5 — is due for publication in May 2013.

Work groups in various fields have been reviewing numerous proposals for additions to the 283 disorders in the current edition. Parental alienation remains on a list of proposals that are subject to further review, though it did not pass muster with the work group dealing with childhood and adolescent disorders.

“There is not sufficient scientific evidence to warrant its inclusion in the DSM,” Regier said in a statement.