Clinical and cost-effectiveness of therapist-guided internet-delivered cognitive behavior therapy for older adults with symptoms of depression: a randomized controlled trial

Depression is a common and significant health problem among older adults. Unfortunately, while effective psychological treatments exist, few older adults access treatment. The aim of the present randomized controlled trial (RCT) was to examine the efficacy, long-term outcomes, and cost-effectiveness of a therapist-guided internet-delivered cognitive behavior therapy (iCBT) intervention for Australian adults over 60. years of age with symptoms of depression. Participants were randomly allocated to either a treatment group (n= 29) or a delayed-treatment waitlist control group (n=. 25). Twenty-seven treatment group participants started the iCBT treatment and 70% completed the treatment within the 8-week course, with 85% of participants providing data at posttreatment. Treatment comprised an online 5-lesson iCBT course with brief weekly contact with a clinical psychologist, delivered over 8. weeks. The primary outcome measure was the Patient Health Questionnaire-9 Item (PHQ-9), a measure of symptoms and severity of depression. Significantly lower scores on the PHQ-9 (Cohen's d=. 2.08; 95% CI: 1.38 - 2.72) and on a measure of anxiety (Generalized Anxiety Disorder-7 Item) (Cohen's d=. 1.22; 95% CI: 0.61 - 1.79) were observed in the treatment group compared to the control group at posttreatment. The treatment group maintained these lower scores at the 3-month and 12-month follow-up time points and the iCBT treatment was rated as acceptable by participants. The treatment group had slightly higher Quality-Adjusted Life-Years (QALYs) than the control group at posttreatment (estimate: 0.012; 95% CI: 0.004 to 0.020) and, while being a higher cost (estimate $52.9. l 95% CI: -. 23.8 to 128.2), the intervention was cost-effective according to commonly used willingness-to-pay thresholds in Australia. The results support the potential efficacy and cost-effectiveness of therapist-guided iCBT as a treatment for older adults with symptoms of depression.