Methodological Recommendations for Trials of Psychological Interventions.

Recent years have seen major developments in psychotherapy research that suggest the need to address critical methodological issues. These recommendations, developed by an international group of researchers, do not replace those for randomized controlled trials, but rather supplement strategies that need to be taken into account when considering psychological treatments. The limitations of traditional taxonomy and assessment methods are outlined, with suggestions for consideration of staging methods. Active psychotherapy control groups are recommended, and adaptive and dismantling study designs offer important opportunities. The treatments that are used, and particularly their specific ingredients, need to be described in detail for both the experimental and the control groups. Assessment should be performed blind before and after treatment and at long-term follow-up. A combination of observer- and self-rated measures is recommended. Side effects of psychotherapy should be evaluated using appropriate methods. Finally, the number of participants who deteriorate after treatment should be noted according to the methods that were used to define response or remission.