Abstract
BACKGROUND: This RCT with two parallel arms will evaluate the efficacy of an internet-delivered transdiagnostic cognitive behavioural therapy (iCBT) intervention for the treatment of clinical depression and/or anxiety in early stage cancer survivors. METHODS/DESIGN: Early stage cancer survivors will be recruited via the research arm of a not-for-profit clinical research unit and randomised to an intervention (iCBT) group or a 'treatment as usual' (TAU) control group. The minimum sample size for each group is 45 people (assuming effect size > 0.6, power of 80%, and alpha at .05), but 10% more will be recruited to account for attrition. A solitary or cumulative diagnosis(es) of Major Depressive Episode (current), Generalised Anxiety Disorder, Illness Anxiety Disorder, Panic Disorder, Agoraphobia, and/or Adjustment disorder will be determined using modules from the Anxiety Disorders Interview Schedule for DSM-5. Depression and anxiety levels with be measured via the total score of the Hospital Anxiety and Depression scale (HADS-T), the primary outcome measure. Secondary measures will include the Kessler 10 to measure general distress, the Fear of Cancer Recurrence Inventory (FCRI) to measure the specific fear of cancer recurrence and the Functional Assessment of Cancer Therapy, General Version 4 (FACT-G) for self-report of physical, social, emotional and functional well-being. iCBT participants will complete the measures before lessons 1 and 5, at post-treatment and at 3-month follow-up. The TAU group will complete similar measures at weeks 1, 8 and 16 of the waiting period. Program efficacy will be determined using intent-to-treat mixed models. Maintenance of gains will be assessed at 3-month follow-up. Mediation analyses using PROCESS will be used to examine the association between change in depressive and anxious symptoms over time and changes in FCRI and FACT-G QOL in separate analysis. DISCUSSION: This is the first RCT looking at iCBT specifically for clinical depression and/or anxiety in a cancer population. Findings will help to direct the role of iCBT in streamlined psycho-social care pathways. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12616000231448, registered 19(th) February 2016 ( www.anzctr.org.au ). This trial protocol is in compliance with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines.