The need for new guidelines to improve the reporting of trials in child and adolescent mental health.

We are pleased to announce the development of CONSORT-SPI: a new reporting guideline for randomised controlled trials (RCTs) of social and psychological interventions. We invite the readership of Journal of Child Psychology and Psychiatry (JCPP) to participate in this project by visiting our website (http://tinyurl.com/CONSORT-study). Well-designed and conducted randomised trials are essential for improving services for children and young people. Not only can they help us to establish ‘what works’ in child and adolescent mental health (Maughan, 2013), but they can also help us to understand how interventions work, and to identify ways in which individual characteristics affect susceptibility to intervention effects. The JCPP has led the way in promoting a high-quality evidence-base for interventions in this field. Over a decade ago, Harrington, Cartwright-Hatton, and Stein (2002) pointed to the importance of ‘well-designed and unambiguously reported RCTs [..to..] provide the best possible evidence about effectiveness of interventions,’ and drew attention to the many special considerations entailed in designing and interpreting RCTs in the field of child mental health. For example, they describe how interventions in this field are complex, involving multiple systems and professions. Moreover, interventions operate against a backdrop of developmental change, and multiple, interacting levels of social influence on the child. Measurement of outcomes often requires multimethod assessment of child well-being, psychopathology, and co-morbidities, as well as family functioning. Thus, given the complexity of these interventions and their outcomes, they are difficult to evaluate. To understand intervention effects and to keep services up to date, researchers, clinicians, commissioners, policymakers, journalists, and consumers rely on research reports of RCTs in scientific journals. Such reports should explain the methods, including the design, delivery, uptake, and context of interventions, and subsequent results. Accurate, complete, and transparent reporting is essential for readers to make best use of new evidence, to achieve