The objective of this article is to provide a detailed description of interactions between patients with depression and pharmacists. Analysis was conducted on patients from the intervention arm (n=268) of an randomized controlled trial that evaluated the impact of a clinical pharmacist on the outcomes for depressed primary care patients from nine metropolitan Boston practices. The main outcome measure was the amount of intervention time spent with patients, physicians, and other activities. Details of the behavioral intervention and a categorization of the activities are offered. Pharmacists reported 978 encounters with 268 patients in 6 months. Eighty percent of patient encounters occurred by telephone. Initial encounters took 45 min if in person and 13.3 min if by telephone. Subsequent encounters followed a similar pattern. Follow-up visits occurred 2.3 times per patient. Physician contact took considerably less time. In total, the pharmacist intervention took 70.3 min per patient over 6 months; 42.2% of encounters involved an activity related to non-antidepressant medication and 85% of encounters involved general support. Other activities (education, advocating antidepressants, and motivating adherence) occurred in at least 50% of encounters. Pharmacists repeated intervention activities in the same category approximately two to three times. Interventions to improve the care of depression in primary care patients must anticipate encountering intense needs for information, personal support, and help negotiating the healthcare system. Research that identifies relationships between the components (active ingredients) of an intervention and the outcomes of care will benefit future intervention strategies and contribute to improved and efficient care.