This study examined how patient characteristics, physician characteristics, the physician's interaction with the health care system, and the physician's interaction with the patient influenced whether patients with a depression diagnosis received an antidepressant prescription and whether they received a SSRI antidepressant, a non-SSRI antidepressant, or both. The 1998 National Ambulatory Medical Care Survey (NAMCS), in the USA, was used for the analysis. Logistic regression was used to examine what characteristics influenced whether a patient with a depression diagnosis received an antidepressant prescription. Next, a multinomial logistic regression model was applied to examine the relative risk of using one type of antidepressant versus another among antidepressant users while correcting for possible sample selections using the Heckman selection model. Sixty-seven percent of patients with a depression diagnosis received an antidepressant. Patients who were seeing providers who were not primary care physicians or psychiatrists, self-paying patients, and patients with neurotic depression were significantly less likely to receive an antidepressant prescription. Patients with depression listed as their first diagnosis were significantly more likely to receive an antidepressant prescription. Patients seeing a psychiatrist were more likely than patients seeing a primary care physician to receive a non-SSRI antidepressant than a SSRI antidepressant. Patients belonging to an HMO that had capitated visits were over four times more likely to receive non-SSRI antidepressants than SSRI antidepressants. Patients with major depression were significantly more likely to receive a non-SSRI antidepressant. Patients with depression as their primary diagnosis and patients who saw psychiatrists were significantly more likely to receive both SSRI and non-SSRI antidepressants rather than just SSRI antidepressants. Patient characteristics, physician characteristics, the physician's interaction with the health care system, and the physician's interaction with the patient all influenced antidepressant prescribing. An especially important finding was that insurance status influenced whether patients received an antidepressant. Health care providers need to take the time to help patients without insurance obtain antidepressant medication if it is needed.