The second half of the twentieth century was a time of considerable innovation in psychotherapy and many new branches of psychotherapy broke off from their origin in traditional psychoanalysis. Family therapists challenged the emphasis on the individual, a fundamental part of all earlier forms of psychotherapy. In family systems theory, it is believed that families operate as systems and that no one member of the family can be understood in isolation from the other members of the family. This is particularly true for married couples, or for children who live with and depend upon their parents.

Although there are many strains of family therapy, including the structural family therapy of Salvador Minuchin, the strategic family therapy of Jay Haley, and the experiential family therapy of Carl Whitaker and Virginia Satir, all family therapists believe in bringing the entire family (or key members) into the room. By working with the family as a whole, therapists can achieve very different effects than can be accomplished in individual therapy alone.

Family therapists address the patterns of interaction between family members. Are the mother and the oldest child allying together against the father? Is the child acting out at school to force his estranged parents to talk to each other? Are the parents failing to set adequate boundaries with their children, giving the children too much power? Family therapy works by helping family members gain insight into their problematic patterns and then work together to change. Unlike psychodynamic therapy, family therapy addresses the present patterns of interaction with far less emphasis on the past, although past history is recognized if it has contributed to present patterns.