Psychological therapies for generalised anxiety disorder

Abstract

Background: Generalised anxiety disorder (GAD) is a highly prevalent condition, characterised by excessive worry or anxiety about everyday events and problems. The effectiveness and comparative effectiveness of psychological therapies as a group has not yet been evaluated in the treatment of GAD. Objectives: To examine the efficacy and acceptability of psychological therapies, categorised as cognitive behavioural therapy (CBT), psychodynamic therapy and supportive therapy, compared with treatment as usual/waiting list (TAU/WL) and compared with one another, for patients with GAD. Search strategy: We searched the Cochrane Depression, Anxiety & Neurosis Group (CCDAN) Controlled Trials Register and conducted supplementary searches of MEDLINE, PsycInfo, EMBASE, LILACS and controlledtrials.comin February 2006. We searched reference lists of retrieved articles, and contacted trial authors and experts in the field for information on ongoing/completed trials. Selection criteria: Randomised and quasi-randomised controlled trials conducted in non-inpatient settings, involving adults aged 18-75 years with a primary diagnosis of GAD, assigned to a psychological therapy condition compared with TAU/WL or another psychological therapy. Data collection and analysis: Data on patients, interventions and outcomes were extracted by two review authors independently, and the methodological quality of each study was assessed. The primary outcome was anxiety reduction, based on a dichotomous measure of clinical response, using relative risk (RR), and on a continuous measure of symptom reduction, using the standardised mean difference (SMD), with 95% confidence intervals. Main results: Twenty five studies (1305 participants) were included in the review, of which 22 studies (1060 participants) contributed data to meta-analyses. Based on thirteen studies, psychological therapies, all using a CBT approach, were more effective than TAU/WL in achieving clinical response at post-treatment (RR 0.64, 95%CI 0.55 to 0.74), and also in reducing anxiety, worry and depression symptoms. No studies conducted longer-term assessments of CBT against TAU/WL. Six studies compared CBT against supportive therapy (nondirective therapy and attention-placebo conditions). No significant difference in clinical response was indicated between CBT and supportive therapy at post-treatment (RR 0.86, 95%CI 0.70 to 1.06), however, significant heterogeneity was indicated, which was partly explained by the number of therapy sessions. Authors' conclusions: Psychological therapy based on CBT principles is effective in reducing anxiety symptoms for short-term treatment of GAD. The body of evidence comparing CBT with other psychological therapies is small and heterogeneous, which precludes drawing conclusions about which psychological therapy is more effective. Further studies examining non-CBT models are required to inform health care policy on the most appropriate forms of psychological therapy in treating GAD. Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.