There is a critical need for treatments that address depression and barriers to mental health care in Parkinson's disease (PD). This randomized-controlled trial will evaluate a 10-session telephone-guided cognitive behavioral self-help program (TH-CBT) for depression in PD (dPD). 72 people with dPD (and their caregivers) will receive either TH-CBT plus enhanced usual care (INTERVENTION GROUP) or enhanced usual care only (CONTROL GROUP). Groups will be compared at baseline, midpoint, endpoint, and 1 and 6 months post-treatment. Participants assigned to the control group with have the opportunity to receive the experimental intervention (TH-CBT) after the data collection period (e.g., after the 6-month follow-up evaluation). Given the public health impact of improved depression treatment in PD, the knowledge to be gained may be significant and the project could directly impact clinical practice.