Online Cognitive Behavioral Therapy for Depressive Symptoms in Parkinson's Disease

We will conduct a remote, randomized controlled trial with delayed start, in order to: 1. Assess the 14-week effectiveness of eCBT for depressive symptoms for patients with PD. 2. Assess long-term outcomes, and predictors of long-term outcomes, of eCBT for depressive symptoms in PD. 3. Explore the impact and clinical correlates of working alliance in eCBT in patients with PD. For the first aim, we hypothesize that: i. 10 week eCBT will reduce the self-reported severity of depressive symptoms in patients with PD after 14 weeks, as compared to patients in a delayed start group, receiving treatment as usual (TAU). ii. 10 week eCBT will reduce the observed severity of depressive symptoms in patients with PD after 14 weeks, as compared to patients in a delayed start group, receiving TAU. i. 10 week eCBT will improve self-reported health related quality of life measured with The 8-item PD Questionnaire after 14 weeks, as compared to patient in a control group receiving TAU. For the second aim, we hypothesize: ii. Participants with 42 week follow up has lasting effects of eCBT, when compared to participants with 28 week follow up. iii. Long-term treatment response from eCBT for depressive symptoms, is predicted by the level of comorbid symptoms of anxiety and impulse control disorders at baseline. iv. Long-term treatment response from eCBT for depressive symptoms, is predicted by the level of comorbid symptoms of anxiety and impulse control disorders at the time of treatment completion. For the third aim, we hypothesize: i. The interrater agreement between patients and CBT therapist on working alliance will be a significant predictor of the acceptability of eCBT, as defined by patient reported experience measures.