Collaborative treatment of late-life depression in primary care (GermanIMPACT): study protocol of a cluster-randomized controlled trial.

BACKGROUND: Depression is not a normal side effect of aging, however it is one of the most prevalent mental health issues in later life, imposing a tremendous burden on patients, their families, and the healthcare system. We describe the experimental implementation of a collaborative, stepped-care model for the treatment of late-life depression (GermanIMPACT trial) in the German primary care context. GermanIMPACT was developed as an adaptation of a successful and widely used American model. The aim of the study is to evaluate the model's applicability to the German primary care setting and its cost-effectiveness.

METHODS/DESIGN: The study will be conducted as a cluster-randomized controlled trial comparing the development of depressive symptoms in primary care patients who either receive treatment as usual (control arm) or treatment according to the GermanIMPACT model (intervention arm). In two German cities (Freiburg and Hamburg), a total of 60 general practice offices will be selected and randomized. Each general practice office will be asked to enroll five patients into the trial who are 60 years of age or older and who show moderate depressive symptoms in the scope of a diagnosed depressive episode, recurrent depressive disorder, or dysthymia. General practices in the control arm will provide treatment as usual; general practices in the intervention arm will work closely with a specially trained care manager and a supervising mental health specialist. Evidence-based elements of the treatment plan manual include patient education, identification and integration of positive activities into the daily routine, relapse prevention, and training of problem-solving techniques as needed. The intervention period per patient will be one year. Data will be collected at baseline, 6, and 12 months. Primary outcome is the patient-reported change of depressive symptoms (Patient Health Questionnaire, PHQ-9). Secondary outcomes include measures of quality of life, anxiety, depression-related behavior, problem-solving skills, resilience, and an overall economic evaluation of the program.

DISCUSSION: The GermanIMPACT trial will provide evidence about the effectiveness, feasibility, and cost-effectiveness of collaborative stepped care in treating late-life depression in German primary care. Positive results will be a first step toward integrating specialized depression care managers into the primary care setting.

TRIAL REGISTRATION: German Clinical Trials Register: DRKS00003589 (September 2012).