Power KG, Simpson R, Swanson V, Wallace LA, Feistner ATC & Sharp D (1990) A controlled comparison of cognitive-behaviour therapy, diazepam, and placebo, alone and in combination, for the treatment of generalised anxiety disorder. Journal of Anxiety Disorders, 4 (4), pp. 267-292. https://doi.org/10.1016/0887-6185%2890%2990026-6
One hundred and one patients meeting the DSM III criteria for Generalised Anxiety Disorder were randomly allocated to Cognitive-Behaviour Therapy, Diazepam, Placebo, Cognitive-Behaviour Theraph + Diazepam, or Cognitive-Behaviour Theraph + Placebo, and treated over 10 weeks. Treatments were balanced for degree of psychologist / patient contact. A fixed dose medication procedure was used. A range of treatment process and outcome measures including psychologist assessor and patient self-report were used. Subsequent post-treatment pharmacological, psychological, and psychiatric treatments were recorded. Outcome measures at end of treatment and at six months follow-up revealed the superiority of all Cognitive-Behaviour Therapy treatments, especially Cognitive-Behaviour Therapy alone, and Cognitive-Behaviour Therapy + Diazepam. Diazepam was no more effective than Placebo. This may have been due to the use of a fixed low dosage regime for the DZ group. Cognitive-Behaviour Thrapy + Diazepam, and Diazepam groups showed no withdrawal symptoms or anxiety recurrence during graded withdrawal. However, the potential effectiveness of DZ and DZ + CBT may have been enhanced by the use of a flexible dose procedure with a higher maximum dose. All Cognitive- Behaviour Therapy groups revealed the lowest incidence of subsequent treatment interventions at six months follow-up.
Journal of Anxiety Disorders: Volume 4, Issue 4