It is the position of Justice for Children that PAS is junk science.

"P.A.S. per se (not “parents lying about abuse allegations”) is not a syndrome.   People lie on the witness stand every day but that does not make it a syndrome.   Various credible studies have documented that the incidence of false allegations of abuse in custody proceedings make up significantly less than 5% of all abuse allegations  in custody proceedings.  When mental health experts or attorneys claim that P.A.S. is a “syndrome”  -- knowing full well that it lacks scientific validity, is the concoction of a disgraced psychologist, and has been soundly rejected by the National Council of Juvenile and Family Court Judges -- that is disingenuous at best and unethical at worst.  Moreover, when it is used as a vehicle to keep children in the custody of men who abuse them, it is also immoral. " - Randy Burton, Founder, Chairman and President - Justice for Children

PAS is touted to be an accepted psychological “syndrome” when, in fact, it has no scientific foundation and has been routinely rejected by courts and mental health professionals as admissible in the courtroom.  Nonetheless, PAS is still being used by unscrupulous attorneys and hired gun “experts” to attack the credibility of, parents, usually mothers, and undermine the testimony of little children who have accused their fathers of unspeakable acts of abuse.

http://www.justiceforchildren.org/pas.asp