The Gordian knot of clinical research in anxiety disorders: some answers, more questions.

Published concurrently with this editorial are two high-quality, thoughtprovoking studies from different research domains, each of which advances yet complicates our understanding of clinical anxiety disorders. One is a multisite randomized controlled trial of psychotherapies for social anxiety disorder (1), the other a meta-analysis of the separation anxiety hypothesis of panic disorder (2). Each study answers key questions that have plagued every clinician and researcher who treats anxiety disorders, yet each raises further issues. Leichsenring et al. (1) conducted a five-site randomized controlled trial of cognitive-behavioral therapy (CBT), psychodynamic therapy (supportive-expressive therapy), and a waiting list condition for social anxiety disorder. In a brave, ambitious, and rigorous study, the authors balanced researcher allegiance, therapist attention, and supervision between modalities. Psychotropic medications were excluded, somewhat limiting generalizability. Carefully blinded independent evaluators employed standard research instruments. Both CBT and psychodynamic therapy outperformed the waiting list condition (no surprise). Surprisingly, however, the dropout rate for the waiting list group matched those of the active treatment groups (24%228%). CBT statistically outperformed psychodynamic therapy in remission rate, which was generally fairly low across treatments (36% for CBT, 26% for psychodynamic therapy), but not in response rate, defined a priori as an improvement.30% on the Liebowitz Social Anxiety Scale (the rates were 60% for CBT and 52% for psychodynamic therapy). As in all randomized controlled trials, the nitty-gritty choices in study design help shape the findings. Which form of CBT to test in such an important study was selfevident: Clark and Wells’s cognitive therapy (3), a commonly practiced model that had been previously studied in clinical trials. No such simple solution attended the dynamic therapy condition, as no form ofmanualized psychodynamic therapy had been developed or tested for patients with social phobia. The investigators chose to use supportive-expressive therapy, newly modified for social phobia, an understandable choice with both strengths and limitations. An enormous strength is that supportive-expressive therapy has been successfully transported around the globe and used to treat multiple psychiatric conditions. The original development of supportive-expressive therapy in the 1970s was a groundbreaking achievement in psychodynamic psychotherapy research, establishing the first successfully manualized supportive dynamic treatment (4), enabling testing of this previously