Do single‐case experimental designs lead to randomised controlled trials of cognitive behavioural therapy interventions for adolescent anxiety and related disorders recommended in the National Institute of Clinical Excellence guidelines? A systematic review

BACKGROUND: Although Cognitive Behavioural Therapy (CBT) is effective for 60% of adolescents with anxiety disorders, only 36% are in remission post‐intervention. This indicates that more effective treatments are needed which should be reflected in the NICE guidelines. We hypothesised that Single‐case experimental designs (SCEDs) may provide a framework for accelerating the development of novel interventions. The primary purpose of this review was to investigate whether SCEDs are currently followed by randomised controlled trials (RCTs) of CBT intervention for adolescent anxiety disorders named in the NICE guidelines. The secondary objective was to investigate whether using SCEDs prior to RCTs could be a helpful approach. METHOD: For the primary search of SCEDs five databases were used (PsycINFO, PubMed, PsycArticles, Web of Science and ProQuest). Nineteen articles met eligibility criteria including a total of 107 participants. For the secondary search of RCTs named in the NICE guidelines for adolescent anxiety disorders 53 articles met inclusion criteria and were included in the systematic review. RESULTS: The 19 SCED studies included in the review were conducted with participants with a diverse range of anxiety disorders and across a range of CBT formats. Two of the SCEDs were followed by RCTs, but neither of these were named in the NICE guidelines for anxiety disorders. All of the SCEDs identified were rated as low quality with none meeting the criteria for the highest or second highest quality rating. From the secondary searches, none of the RCTs named in the NICE guide were preceded by SCEDs. CONCLUSIONS: It was concluded that currently SCEDs were not followed by RCTs of CBT interventions named in the NICE guidelines for adolescent anxiety disorders. However, it was suggested that SCEDs may provide an important framework for the development of more effective interventions for adolescents with anxiety.