Anxiety disorders, including panic disorder with or without agoraphobia, generalized anxiety disorder, social anxiety disorder, specific phobias, and separation anxiety disorder, are the most prevalent mental disorders and are associated with immense health care costs and a high burden of disease. According to large population-based surveys, up to 33.7% of the population are affected by an anxiety disorder during their lifetime. Substantial underrecognition and undertreatment of these disorders have been demonstrated. There is no evidence that the prevalence rates of anxiety disorders have changed in the past years. In cross-cultural comparisons, prevalence rates are highly variable. It is more likely that this heterogeneity is due to differences in methodology than to cultural influences. Anxiety disorders follow a chronic course; however, there is a natural decrease in prevalence rates with older age. Anxiety disorders are highly comorbid with other anxiety disorders and other mental disorders.

To our knowledge, no previous meta-analysis has attempted to compare the efficacy of pharmacological, psychological and combined treatments for the three main anxiety disorders (panic disorder, generalized anxiety disorder and social phobia). Pre-post and treated versus control effect sizes (ES) were calculated for all evaluable randomized-controlled studies (n = 234), involving 37,333 patients. Medications were associated with a significantly higher average pre-post ES [Cohen's d = 2.02 (1.90-2.15); 28,051 patients] than psychotherapies [1.22 (1.14-1.30); 6992 patients; P < 0.0001]. ES were 2.25 for serotonin-noradrenaline reuptake inhibitors (n = 23 study arms), 2.15 for benzodiazepines (n = 42), 2.09 for selective serotonin reuptake inhibitors (n = 62) and 1.83 for tricyclic antidepressants (n = 15). ES for psychotherapies were mindfulness therapies, 1.56 (n = 4); relaxation, 1.36 (n = 17); individual cognitive behavioural/exposure therapy (CBT), 1.30 (n = 93); group CBT, 1.22 (n = 18); psychodynamic therapy 1.17 (n = 5); therapies without face-to-face contact (e.g. Internet therapies), 1.11 (n = 34); eye movement desensitization reprocessing, 1.03 (n = 3); and interpersonal therapy 0.78 (n = 4). The ES was 2.12 (n = 16) for CBT/drug combinations. Exercise had an ES of 1.23 (n = 3). For control groups, ES were 1.29 for placebo pills (n = 111), 0.83 for psychological placebos (n = 16) and 0.20 for waitlists (n = 50). In direct comparisons with control groups, all investigated drugs, except for citalopram, opipramol and moclobemide, were significantly more effective than placebo. Individual CBT was more effective than waiting list, psychological placebo and pill placebo. When looking at the average pre-post ES, medications were more effective than psychotherapies. Pre-post ES for psychotherapies did not differ from pill placebos; this finding cannot be explained by heterogeneity, publication bias or allegiance effects. However, the decision on whether to choose psychotherapy, medications or a combination of the two should be left to the patient as drugs may have side effects, interactions and contraindications.

Anxiety disorders (generalized anxiety disorder, panic disorder/agoraphobia, social anxiety disorder, and others) are the most prevalent psychiatric disorders, and are associated with a high burden of illness. Anxiety disorders are often underrecognized and undertreated in primary care. Treatment is indicated when a patient shows marked distress or suffers from complications resulting from the disorder. The treatment recommendations given in this article are based on guidelines, meta-analyses, and systematic reviews of randomized controlled studies. Anxiety disorders should be treated with psychological therapy, pharmacotherapy, or a combination of both. Cognitive behavioral therapy can be regarded as the psychotherapy with the highest level of evidence. First-line drugs are the selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors. Benzodiazepines are not recommended for routine use. Other treatment options include pregabalin, tricyclic antidepressants, buspirone, moclobemide, and others. After remission, medications should be continued for 6 to 12 months. When developing a treatment plan, efficacy, adverse effects, interactions, costs, and the preference of the patient should be considered.

Not only psychotherapy, but also medications and, to a lesser extent, placebo conditions have enduring effects. Long-lasting treatment effects observed in the follow-up period may be superimposed by effects of spontaneous remission or regression to the mean.Declaration of interestIn the past 12 months and in the near future, Dr Bandelow has been/will be on the speakers/advisory board for Hexal, Mundipharma, Lilly, Lundbeck, Pfizer and Servier. Dr Wedekind was on the speakers' board of AstraZeneca, Essex Pharma, Lundbeck and Servier. All other authors have nothing to declare.