Does Parental Alienation Syndrome Exist?

"A 10-year-old child accused of fatally shooting his father this summer has become a national poster boy for a controversial and unofficial psychiatric disorder: Parental Alienation Syndrome," according to a Houston Chronicle article:

...41-year-old Rick Lohstroh, who was killed on Aug. 27 outside his ex-wife's
Katy home. After a bitter divorce in 2003, Lohstroh was picking up his two sons
for a visit under a joint-custody agreement when the 10-year-old shot him from
the back seat of the car, police said. Since then, advocates have pointed to
Lohstroh's death to illustrate that acrimonious divorces can prompt an angry
parent to turn a child against another parent.

According to Dr Richard Gardner:

...parental alienation syndrome (PAS) is a disorder that arises almost
exclusively in the context of child-custody disputes. In this disorder, one
parent induces a program of denigration against the other parent. However, this is not simply a matter of "brainwashing" or "programming" in that the children contribute their own elements into the campaign of denigration. It is this combination of factors that justifiably warrants the designation PAS.

Dr Gardner is carrying on a campaign to get the concept incorporated into the official diagnosis manual of the American Psychiatric Association.

But the theory has many critics, particularly among workers in the child-abuse field who fear that it may perpetuate denial about the rate of child abuse. (That is, a parent reporting abuse by an ex-spouse might have the report ignored under the guise that the real issue is PAS.) So, an interesting war of words (here, for example) has developed over the issue.

By the way, antidepressants have also been blamed in the case above. In fact, the grandparents reportedly are suing Prozac's maker, claiming the medication caused the child's aggression.