Guided, internet-based, rumination-focused cognitive behavioural therapy (i-RFCBT) versus a no-intervention control to prevent depression in high-ruminating young adults, along with an adjunct assessment of the feasibility of unguided i-RFCBT, in the REducing Stress and Preventing Depression trial (RESPOND): study protocol for a phase III randomised controlled trial.

BACKGROUND Depression is a global health challenge. Prevention is highlighted as a priority to reduce its prevalence. Although effective preventive interventions exist, the efficacy and coverage can be improved. One proposed means to increase efficacy is by using interventions to target specific risk factors, such as rumination. Rumination-focused CBT (RFCBT) was developed to specifically target depressive rumination and reduces acute depressive symptoms and relapse for patients with residual depression in a randomised controlled trial. Preliminary findings from a Dutch randomised prevention trial in 251 high-risk 15- to 22-year-old subjects selected with elevated worry and rumination found that both supported internet-RFBCT and group-delivered RFCBT equally reduced depressive symptoms and the onset of depressive cases over a period of 1 year, relative to the no-intervention control. METHODS/DESIGN A phase III randomised controlled trial following the Medical Research Council (MRC) Complex Interventions Framework will extend a Dutch trial to the United Kingdom, with the addition of diagnostic interviews, primarily to test whether guided internet-RFCBT reduces the onset of depression relative to a no-intervention control. High-risk young adults (aged 18 to 24 years), selected with elevated worry/rumination and recruited through university and internet advertisement, will be randomised to receive either guided internet-RFCBT, supported by clinical psychologists or mental health paraprofessionals, or a no-intervention control. As an adjunct arm, participants are also randomised to unguided internet-RFCBT self-help to provide an initial test of the feasibility and effect size of this intervention. While participants are also randomised to unguided internet-RFCBT, the trial was designed and powered as a phase III trial comparing guided internet-RFCBT versus a no-intervention control. In the comparison between these two arms, the primary outcomes are as follows: a) onset of major depressive episode over a 12-month period, assessed with a Structured Clinical Interview for Diagnosis at 3 months (post-intervention), 6 months and 15 months after randomisation. The following secondary outcomes will be recorded: the incidence of generalized anxiety disorder, symptoms of depression and anxiety, and levels of worry and rumination, measured at baseline and at the same follow-up intervals. In relation to the pilot investigation of unguided internet-RFCBT (the adjunct intervention arm), we will assess the feasibility and acceptability of the data-collection procedures, levels of attrition, effect size and acceptability of the unguided internet-RFCBT intervention. DISCUSSION Widespread implementation is necessary for effective prevention, suggesting that the internet may be a valuable mode of delivery. Previous research suggests that guided internet-RFCBT reduces incidence rates relative to controls. We are also interested in developing and evaluating an unguided version to potentially increase the availability and reduce the costs. TRIAL REGISTRATION Current Controlled Trials ISRCTN12683436 . Date of registration: 27 October 2014.