Non-adherence and non-response in the treatment of anxiety disorders.

Among the best established treatments for anxiety disorders are cognitive-behavioral interventions and serotonin reuptake inhibitors. Although clinically useful, these therapies are far from universally efficacious; some patients are unable to complete treatment, and many treatment completers fail to achieve clinically significant improvement. A review of meta-analyses on the treatment of anxiety disorders reveals that about a fifth of patients drop out prematurely and a third of treatment completers are classified as non-responders. In this article we examine the predictors of, and potential solutions for, the problems of treatment non-adherence and non-response to cognitive-behavioral and serotonergic treatments of adult anxiety disorders. Despite decades of research, few reliable predictors have been identified, and no predictor has been consistently supported in the literature. However, there is suggestive evidence that risk of premature dropout is associated with low treatment motivation, side effects, and practical barriers to attending sessions. There is also suggestive evidence that poor response is associated with severe pretreatment psychopathology and comorbidity, as well as high expressed emotion in the patient's family environment. Methods for better estimating treatment prognosis are proposed and possible directions for improving treatment outcome are discussed.