Background: Despite recommendations to screen adults for depression in primary care, little is known about how people across education levels decide to treat their depression and factors that influence their decision. Methods: We conducted a secondary analysis of a national, probability-based web survey in Englishspeaking adults aged 40 or older living in the United States who reported they discussed starting or continuing an antidepressant with their clinician in the past 2 years. Respondents answered questions about knowledge, decision-making process, and demographics. Education level was analyzed using 5 ordered categories. The Shared Decision Making (SDM) Process score was used to assess patient involvement. Descriptive statistics, 2 tests, analysis of variance, and regression models were used to describe the data and test associations. Results: Of the 5682 people invited, 3396 answered questions about health decisions (59.8% response rate) and 385 reported discussing antidepressants. The mean percentage of knowledge questions answered correctly increased as education level increased (P ؍ .008). The mean SDM Process score also increased with education (P ؍ .001). There was an association between education and who made the treatment decision, suggesting that for respondents with less education, the clinician was more likely to decide (P ؍ .001). Respondents with less education were less likely to report they would definitely make the same decision again (P ؍ .000). Conclusions: Those with less education were even less informed, had lower SDM Process scores and were less likely to think they made the right decision about antidepressants. There is a need to ensure patients are better informed about and involved in treatment for depression. (J Am Board Fam Med 2020;33:80-90.