The dose-effect relationship in psychotherapy: a defining achievement for Dr. Kenneth Howard.

This article summarizes the Howard, Kopta, Krause, and Orlinsky (1986) study and notes its contributions to the field of psychotherapy. These contributions include (a) being the flagship study to estimate how psychotherapy is enough, (b) establishing number of sessions or dose as the common treatment unit of psychotherapy, (c) providing the first dosage standard for determining treatment groups, (d) inspiring the recent wave of effectiveness research, and (e) presenting the first methodology that assesses the efficiency of psychotherapy. Copyright 2003 Wiley Periodicals, Inc. J Clin Psychol.