Skip to main content
    • Aa
    • Aa

A meta-analytic review of the effects of psychotherapy control conditions for anxiety disorders

  • J. A. J. Smits (a1) and S. G. Hofmann (a2)

Little is known about the magnitude of improvement associated with psychotherapy control conditions for adult anxiety disorders. This information is important for the design of psychosocial treatment efficacy studies.


We performed a computerized search of treatment outcome studies of anxiety disorders conducted between the first available year and 1 March 2007. In addition, we examined the reference lists from identified articles and asked international experts to identify eligible studies. We included studies that randomly assigned adult patients suffering from anxiety disorders to either cognitive–behavioral treatment or psychotherapy control condition. For each study, the two authors independently selected psychometrically sound measures of anxiety disorder severity. In addition, we collected data on attrition and treatment response.


Of the 1165 studies that were initially identified, 19 studies (454 patients) met inclusion criteria and were included in the analyses. The random effects analysis yielded a pre- to post-treatment Hedges' g effect size of 0.45 (95% confidence interval 0.35–0.46, z=8.50, p<0.001). The mean weighted response and attrition rates were 25.0% and 14.2%, respectively. There was no evidence for publication bias, nor was there a significant relationship between the effect size and diagnostic group, study year or number of treatment sessions.


Psychotherapy control conditions are associated with significant improvements when administered to adults suffering from anxiety disorders. In addition, they are associated with a relatively low attrition rate. These findings can inform the design of future psychotherapy outcome studies.

Corresponding author
*Address for correspondence: J. A. J. Smits, Ph.D., Department of Psychology, Southern Methodist University, Dedman College, PO Box 750442, Dallas, TX 75275, USA. (Email:
Hide All
Bailar JC (2001). The powerful placebo and the Wizard of Oz. New England Journal of Medicine 344, 16301632.
Baker SL, Heinrichs N, Kim HJ, Hofmann SG (2002). The Liebowitz Social Anxiety Scale as a self-report instrument: a preliminary psychometric analysis. Behaviour Research and Therapy 40, 701715.
Barlow DH, Gorman JM, Shear MK, Woods SW (2000). Cognitive–behavioral therapy, imipramine, or their combination for panic disorder: a randomized controlled trial. Journal of the American Medical Association 283, 25292536.
Beck AT, Epstein N, Brown G, Steer RA (1988). An inventory for measuring clinical anxiety: psychometric properties. Journal of Consulting and Clinical Psychology 56, 893897.
Beecher HK (1955). The powerful placebo. Journal of the American Medical Association 159, 16021606.
Blake DD, Weathers FW, Nagy LM, Kaloupek DG, Gusman FD, Charney DS, Keane TM (1995). The development of a clinician administered PTSD scale. Journal of Traumatic Stress 8, 7590.
Blanchard EB, Hickling EJ, Devineni T, Veazey CH, Galovski TE, Mundy E, Malta LS, Buckley TC (2003). A controlled evaluation of cognitive behavioral therapy for posttraumatic stress in motor vehicle accident survivors. Behaviour Research and Therapy 41, 7996.
Borenstein M, Hedges L, Higgins J, Rothstein H (2005). Comprehensive Meta-Analysis, version 2. Biostat, Inc.: Englewood, NJ.
Borkovec TD, Costello E (1993). Efficacy of applied relaxation and cognitive–behavioral therapy in the treatment of generalized anxiety disorder. Journal of Consulting and Clinical Psychology 61, 611619.
Bruce SE, Yonkers KA, Otto MW, Eisen JL, Weisberg RB, Pagano M, Shea MT, Keller MB (2005). Influence of psychiatric comorbidity on recovery and recurrence in generalized anxiety disorder, social phobia, and panic disorder: a 12-year prospective study. American Journal of Psychiatry 162, 11791187.
Bryant RA, Harvey AG, Dang ST, Sackville T, Basten C (1998). Treatment of acute stress disorder: a comparison of cognitive–behavioral therapy and supportive counseling. Journal of Consulting and Clinical Psychology 66, 862866.
Bryant RA, Moulds ML, Guthrie RM, Dang ST, Nixon RD (2003 a). Imaginal exposure alone and imaginal exposure with cognitive restructuring in treatment of posttraumatic stress disorder. Journal of Consulting and Clinical Psychology 71, 706712.
Bryant RA, Moulds ML, Guthrie RM, Nixon RDV (2005). The additive benefit of hypnosis and cognitive-behavioral therapy in treating acute stress disorder. Journal of Consulting and Clinical Psychology 73, 334340.
Bryant RA, Moulds ML, Nixon RVD (2003 b). Cognitive behaviour therapy of acute stress disorder: a four-year follow-up. Behaviour Research and Therapy 41, 489494.
Bryant RA, Sackville T, Dang ST, Moulds M, Guthrie R (1999). Treating acute stress disorder: an evaluation of cognitive behavior therapy and supportive counseling techniques. American Journal of Psychiatry 156, 17801786.
Bystritsky A (1990). Development of a multidimensional scale of anxiety. Journal of Anxiety Disorders 4, 99115.
Cohen J (1988). Statistical Power Analysis for the Behavioral Sciences, 2nd edn. Erlbaum: Hillsdale, NJ.
Cooper H, Hedges LV (1994). Combining estimates of effect size. In The Handbook of Research Synthesis, pp. 261281. Russell Sage Foundation: New York, NY.
Cottraux J, Note I, Albuisson E, Yao SN, Note B, Mollard E, Bonasse F, Jalenques I, Guérin J, Coudert AJ (2000). Cognitive behavior therapy versus supportive therapy in social phobia: a randomized controlled trial. Psychotherapy and Psychosomatics 69, 137146.
Craske MG, Maidenberg E, Bystritsky A (1995). Brief cognitive–behavioral versus nondirective therapy for panic disorder. Journal of Behavior Therapy and Experimental Psychiatry 26, 113120.
Derogatis LR (1977). SCL-90 Administration, Scoring, and Procedures Manual for the Revised Version. Johns Hopkins University Press: Baltimore, MD.
Derogatis LR, Melisaratos N (1983). The Brief Symptom Inventory: an introductory report. Psychological Medicine 13, 595605.
DiNardo PA, Barlow DH (1988). Anxiety Disorder Interview Schedule – Revised (ADIS-R). Phobia and Anxiety Disorders Clinic, State University of New York: Albany, NY.
DiNardo PA, Brown TA, Barlow DH (1994). Anxiety Disorders Interview Schedule for DSM-IV. Center for Anxiety and Related Disorders at Boston University: Boston, MA.
Foa EB (1995). Post-Traumatic Stress Diagnostic Scale (PDS). National Computer Systems: Minneapolis, MN.
Foa EB, Riggs DS, Dancu CV, Rothbaum BO (1993). Reliability and validity of a brief instrument for assessing post-traumatic stress disorder. Journal of Traumatic Stress 6, 459473.
Foa EB, Rothbaum BO, Riggs DS, Murdock TB (1991). Treatment of posttraumatic stress disorder in rape victims: a comparison between cognitive–behavioral procedures and counseling. Journal of Consulting and Clinical Psychology 59, 715723.
Frisch MB, Cornell J, Villanueva M, Retzlaff PJ (1992). Clinical validation of the Quality Of Life Inventory: a measure of life satisfaction for use in treatment planning and outcome assessment. Psychological Assessment 4, 92101.
Glass CR, Merluzzi T, Biever JL, Larsen K (1982). Cognitive assessment of social anxiety: development and validation of a self-statement questionnaire. Cognitive Therapy and Research 6, 3755.
Goodman WK, Price LH, Rasmussen SA, Mazure C, Fleischmann RL, Hill CL, Heninger GR, Charney DS (1989). The Yale-Brown Obsessive Compulsive Scale, I: development, use, and reliability. Archives of General Psychiatry 46, 10061011.
Greist JH, Marks IM, Baer L, Kobak KA (2002). Behavior therapy for obsessive–compulsive disorder guided by a computer or by a clinician compared with relaxation as a control. Journal of Clinical Psychiatry 63, 138145.
Guy W (1976). ECDEU Assessment Manual for Psychopharmacology, publication ADM 76-338 (ed. Guy W.), pp. 217222. Department of Health, Education and Welfare: Washington, DC.
Hamilton M (1959). The measurement of anxiety states by rating. British Journal of Medical Psychology 32, 5055.
Harding TW, de Arango MV, Baltazar J, Climent CE, Ibrahim HH, Ladrido-Ignacio L, Murthy RS, Wig NN (1980). Mental disorders in primary health care: a study of their frequency and diagnosis in four developing countries. Psychological Medicine 10, 231241.
Hedges LV, Olkin I (1985). Statistical Methods for Meta-Analysis. Academic Press: New York, NY.
Hedges LV, Vevea JL (1998). Fixed- and random-effects models in meta-analysis. Psychological Methods 3, 486504.
Heimberg RG, Liebowitz MR, Hope DA, Schneier FR, Holt CS, Welkowitz LA, Juster HR, Campeas R, Bruch MA, Cloitre M, Fallon B, Klein DF (1998). Cognitive behavioral group therapy vs phenelzine therapy for social phobia: 12-week outcome. Archives of General Psychiatry 55, 11331141.
Hodgson RJ, Rachman S (1977). Obsessive compulsive complaints. Behaviour Research and Therapy 15, 389395.
Hofmann SG, Smits JA (2008). Cognitive–behavioral therapy for adult anxiety disorders: a meta-analysis of randomized placebo-controlled trials. Journal of Clinical Psychiatry. Published online: 5 March 2008. PMID: 18363421.
Hofmann SG, Weinberger J (2007). The Art and Science of Psychotherapy. Routledge (Taylor and Francis): New York, NY.
Horowitz MJ, Wilner N, Alvarez W (1979). Impact of Event Scale: a measure of subjective stress. Psychosomatic Medicine 41, 209218.
Hrobjartsson A, Gotsche PC (2001). Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. New England Journal of Medicine 344, 15941602.
Hrobjartsson A, Gotsche PC (2007). Wambold et al.'s reiterate spin in the conclusion of a re-analysis of placebo versus no-treatment trials despite similar results as in original review. Journal of Clinical Psychotherapy 63, 405408.
Huppert JD, Schultz LT, Foa EB, Barlow DH, Davidson JR, Gorman JM, Shear MK, Simpson HB, Woods SW (2004). Differential response to placebo among patients with social phobia, panic disorder, and obsessive–compulsive disorder. American Journal of Psychiatry 161, 14851487.
Jacobson NS, Truax P (1991). Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology 59, 1219.
Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJM, Gavaghan DJ, McQuay HJ (1996). Assessing the quality of reports of randomized clinical trials: is blinding necessary? Controlled Clinical Trials 17, 112.
Keller MB, Lavori PW, Friedman B, Nielsen E, Endicott J, Mcdonal-Scott P, Andreasen NC (1987). A longitudinal interval follow-up evaluation: a comprehensive method for assessing outcome and prospective longitudinal studies. Archives of General Psychiatry 44, 540548.
Kellner R, Sheffield BF (1973). A self-rating scale of distress. Psychological Medicine 3, 88100.
Khawaja NG, Oei TP (1992). Development of a catastrophic cognition questionnaire. Journal of Anxiety Disorders 6, 305318.
Klein DF (1996). Preventing hung juries about therapy studies. Journal of Consulting and Clinical Psychology 64, 8187.
Liebowitz MR (1987). Social phobia. Modern Problems of Pharmacopsychiatry 22, 141173.
Liebowitz MR, Schneier F, Campeas R, Hollander E, Hatterer J, Fyer A, Gorman JM, Papp L, Davies S, Gully R, Klein DF (1992). Phenelzine vs. atenolol in social phobia: a placebo-controlled comparison. Archives of General Psychiatry 49, 290300.
Lindsay M, Crino R, Andrews G (1997). Controlled trial of exposure and response prevention in obsessive–compulsive disorder. British Journal of Psychiatry: Journal of Mental Science 171, 135139.
Luborsky L, Diguer L, Seligman D, Rosenthal R, Krause E, Johnson S, Halperin G, Bishop M, Berman JS, Schweizer E (1999). The researcher's own therapy allegiances: a ‘wild card’ in comparisons of treatment efficacy. Clinical Psychology: Science and Practice 6, 96106.
Lucas RA (1994). A comparative treatment outcome study of social phobia. Dissertation Abstracts 54, 6465.
Marks IM, Connolly J, Hallam RS (1973). The psychiatric nurse as therapist. British Medical Journal 2, 156160.
Marks IM, Lovell K, Noshirvani H, Livanou M, Thrasher S (1998). Treatment of posttraumatic stress disorder by exposure and/or cognitive restructuring. Archives of General Psychiatry 55, 317325.
Marks IM, Mathews AM (1979). Brief standard self-rating for phobic patients. Behaviour Research and Therapy 17, 263267.
Mattick RP, Clarke JC (1998). Development and validation of measures of social scrutiny fear and social interaction anxiety. Behaviour Research and Therapy 36, 455470.
Mavissakalian MR, Jones BA, Olson SC (1990). Absence of placebo response in obsessive–compulsive disorder. Journal of Nervous and Mental Disease 178, 268270.
McDonagh A, Friedman M, McHugo G, Ford J, Sengupta A, Mueser K, Demment CC, Fournier D, Schnurr PP, Descamps M (2005). Randomized trial of cognitive–behavioral therapy for chronic posttraumatic stress disorder in adult female survivors of childhood sexual abuse. Journal of Consulting and Clinical Psychology 73, 515524.
Meyer TJ, Miller ML, Metzger RL, Borkovec TD (1990). Development and validation of the Penn State Worry Questionnaire. Behaviour Research and Therapy 28, 487495.
Neuner F, Schauer M, Klaschik C (2004). A comparison of narrative exposure therapy, supportive counseling, and psychoeducation for treating posttraumatic stress disorder in an African refugee settlement. Journal of Consulting and Clinical Psychology 72, 579587.
Piercy MA, Sramec JJ, Kurtz NM, Cutler NR (1996). Placebo response in anxiety disorders. Annals of Pharmacotherapy 30, 10131019.
Quitkin FM (1999). Placebos, drug effects, and study design: a clinicians' guide. American Journal of Psychiatry 156, 829836.
Quitkin FM, Rabkin JG, Gerald J, Davis J, Klein DF (2000). Validity of clinical trials of antidepressants. The American Journal of Psychiatry 157, 327337.
Reiss A, Peterson R, Gursky D, McNally R (1986). Anxiety sensitivity, anxiety frequency, and the prediction of fearfulness. Behaviour Research and Therapy 24, 18.
Rosenthal R (1979). The file drawer problem and tolerance for null results. Psychological Bulletin 86, 638641.
Rosenthal R (1991). Meta-Analytic Procedures for Social Research, revised edn. Sage Publications, Inc.: Thousand Oaks, CA.
Sanavio E (1988). Obsessions and compulsions: The Padua Inventory. Behaviour Research and Therapy 26, 169177.
Smits JA, Powers MB, Buxkamper R, Telch MJ (2006). The efficacy of videotape feedback for enhancing the effects of exposure-based treatment for social anxiety disorder: a controlled investigation. Behavior Research and Therapy 44, 17731785.
Spielberger CD, Gorsuch RL, Lushene RE (1970). State–Trait Anxiety Inventory, Manual. Consulting Psychologists Press: Palo Alto, CA.
Turner SM, Beidel DC, Dancu CV, Stanley MA (1989). An empirically derived inventory to measure social fears and anxiety: The Social Phobia and Anxiety Inventory. Journal of Consulting and Clinical Psychology 1, 3540.
Wampold BE, Imel ZE, Minami T (2007). The placebo effect: ‘relatively large’ and ‘robust’ enough to survive another assault. Journal of Clinical Psychotherapy 63, 401403.
Wampold BE, Minami T, Tierney SC, Baskin TW, Bhati KS (2005). The placebo is powerful: estimating placebo effects in medicine and psychotherapy from randomized clinical trials. Journal of Clinical Psychotherapy 61, 835854.
Ware J Jr., Kosinski M, Keller SD (1996). A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Medical Care 34, 220233.
Watson D, Friend R (1969). Measurement of social-evaluative anxiety. Journal of Consulting and Clinical Psychology 33, 448457.
Weathers FW, Litz B, Huska JA, Keane TM (1995). PCL-C for DSM-IV (PTSD Checklist). National Center for Posttraumatic Stress Disorder: Boston, MA.
Wetherell JL, Gatz M, Craske MG (2003). Treatment of generalized anxiety disorder in older adults. Journal of Consulting and Clinical Psychology 71, 3140.
World Health Organization (1997). World Health Organization, Composite International Diagnostic Interview (CIDI) Researcher's Manual. American Psychiatric Press Inc.: Washington, DC.
Zung WWK (1975). A rating instrument for anxiety disorders. Psychosomatics: Journal of Consultation Liaison Psychiatry 12, 371379.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Psychological Medicine
  • ISSN: 0033-2917
  • EISSN: 1469-8978
  • URL: /core/journals/psychological-medicine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Altmetric attention score

Full text views

Total number of HTML views: 4
Total number of PDF views: 42 *
Loading metrics...

Abstract views

Total abstract views: 239 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 22nd October 2017. This data will be updated every 24 hours.