ALTHOUGH there is no convincing evidence from group outcome studies that psychotherapy is effective,1 recent work2 suggests that groups of patients so treated show both negative and positive change when compared to untreated controls. Those treated tend to be widely dispersed from improved to worsened, while untreated control subjects usually show slight improvement and cluster about the mean. The variability in outcome following psychotherapy appears to depend on therapist and to a lesser extent on patient characteristics. Thus the evidence suggests that behavioral change occurs during psychotherapy, but is masked in largesample statistical-outcome studies, where positive and negative therapeutic effects cancel out.
An alternative research approach is the controlled study of the single case. This approach allows for detailed and sensitive investigation of the variables responsible for behavioral change in psychotherapy. Individualized and direct measures of pertinent symptomatic behaviors can be devised and monitored throughout an experimental therapy. The effect of a single therapeutic variable
Agras S, Leitenberg H, Barlow DH. Social Reinforcement in the Modification of Agoraphobia. Arch Gen Psychiatry. 1968;19(4):423–427. doi:10.1001/archpsyc.1968.01740100039006