Efficacy of Psychotherapy for Depressed Parkinson's Disease Patients

The primary aim of this study is to determine whether IPT is more efficacious than an intervention that controls for non-specific factors (i.e., supportive psychotherapy) in reducing depressive symptoms. A secondary aim is to determine whether IPT is better than supportive therapy in improving quality of life, interpersonal functioning, attachment patters, and motor symptoms, and whether treatment gains are durable at 6-months follow-up. An exploratory aim of the study is identify moderators and mediators of treatment outcome. Patients who meet study criteria will be randomly assigned to either 12 sessions of IPT or 12 sessions of supportive therapy. The primary efficacy measure (Hamilton Depression Rating Scale) will be administered at baseline, weeks 6 and 12, and at 6 months follow-up.

Inclusion criteria

• Outpatients with idiopathic Parkinson's disease and between stages 1 and 3 in the modified Hohn & Yahr Clinical Staging Scale
• Diagnosis of a depressive disorder
• Score ≥ 12 on the 17-item Hamilton Depression Rating Scale
• Living independently

Exclusion criteria

• History of bipolar disorder or psychotic symptoms (other than drug induced)
• Substance-related disorders in the last 12 months
• Acutely suicidal or history of suicide attempts in the past 5 years
• Presence of cognitive deficits (i.e., score ≤ 24 on the Mini Mental Status Exam) or history of significant cognitive disorders
• Presence of other significant neurological problems
• Presence of unstable comorbid medical conditions
• Currently receiving psychotherapy
• Unable to attend weekly therapy sessions