The number of clinical trials in body dysmorphic disorder (BDD) has steadily increased in recent years. As the number of studies grows, it is important to define the most empirically useful definitions for response and remission in order to enhance field-wide consistency and comparisons of treatment outcomes across studies. In this study, we aim to operationally define treatment response and remission in BDD.

We pooled data from three randomized controlled trials of cognitive-behavior therapy (CBT) for BDD (combined n = 153) conducted at four academic sites in Sweden, the USA, and England. Using signal detection methods, we examined the Yale-Brown Obsessive Compulsive Scale modified for BDD (BDD–YBOCS) score that most reliably identified patients who responded to CBT and those who achieved remission from BDD symptoms at the end of treatment.

A BDD–YBOCS reduction ⩾30% was most predictive of treatment response as defined by the Clinical Global Impression (CGI) – Improvement scale (sensitivity 0.89, specificity 0.91, 91% correctly classified). At post-treatment, a BDD–YBOCS score ⩽16 was the best predictor of full or partial symptom remission (sensitivity 0.85, specificity 0.99, 97% correctly classified), defined by the CGI – Severity scale.

Based on these results, we propose conceptual and operational definitions of response and full or partial remission in BDD. A consensus regarding these constructs will improve the interpretation and comparison of future clinical trials, as well as improve communication among researchers, clinicians, and patients. Further research is needed, especially regarding definitions of full remission, recovery, and relapse.

Anxiety disorders are associated with substantial functional limitations but the course of functioning following symptom remission remains largely unknown.

Using data from the Netherlands Study of Depression and Anxiety (NESDA), we examined the 2-year trajectories of functioning in participants with chronic (n = 586) or remitting anxiety disorders (n = 385) and in healthy controls (n = 585). In participants with remitting anxiety disorders, we identified predictors of functioning from among sociodemographic, clinical and vulnerability variables. Data were analysed using linear mixed models (LMMs). Functioning was assessed with the World Health Organization Disability Assessment Schedule II (WHO DAS II).

At baseline, participants with remitting anxiety disorders functioned significantly better than those with chronic anxiety disorders, but significantly worse than controls. In both anxiety disorder groups, most impairment was reported in social functioning, occupational functioning and cognition. During the follow-up, functioning improved in both groups, probably due to treatments received. Participants who achieved symptom remission experienced moderate improvements in social functioning and cognition but not in occupational functioning. Of those who remitted, 45.8% reported functioning scores similar to healthy controls whereas 28.5% still functioned at the level of those with chronic anxiety disorders. Worse functioning was predicted by severe anxiety disorders, use of psychological treatment, co-morbid depressive disorders and maladaptive personality traits.

In anxiety disorders, symptom remission is accompanied by improvements in functioning but significant functional impairments may persist because of co-morbid disorders, lower functioning prior to the onset of the anxiety disorder or residual subthreshold anxiety symptoms.