The alienation of children from parents in the course of high-conflict family law litigation was first observed noted by the mental health community in 1976. In 1987, Dr. Richard Gardner gave this problem the label "Parental Alienation Syndrome," which he used to describe a disorder in children that he said occurs in the course of disputes between separated parents about their children's parenting arrangements.

Gardner's take on this problem was not without controversy and the problem and Gardner's theory has continued to be studied, critiqued, and updated by the mental health community. In fact, I think it's fair to say that Parental Alienation Syndrome, as Gardner originally framed it, has largely been discredited. No one doubts that parental alienation can occur when parents separate; the questions raised by mental health researchers and other professionals largely concern whether Parental Alienation Syndrome is a diagnosable "syndrome" at all and the many, varied reasons why a child can come to resist seeing a parent. The current thinking on alienation, and a related problem called estrangement, has become quite nuanced. The most recent significant work on parental alienation comes from Drs. Joan Kelly and Janet Johnston, but since Gardner came up with his formulation of Parental Alienation Syndrome first, that's where we'll start.