The authors examined automated pharmacy and visit data for 502 members of a large-staff model health maintenance organization (HMO) who had been diagnosed with depression and started on antidepressants by their primary-care providers. Older patients (age >/=60; n=110) were less likely than younger adults (age 18-59, n=110) to receive adequate doses of antidepressant medications for 30 or 90 days. Older adults were also less likely than younger adults to receive more than two primary-care visits for depression in the 12 weeks after receiving a new antidepressant prescription and were less likely to receive specialty mental health care in the 6 months after receiving a new antidepressant prescription.