Objective: This study examines the effect of antidepressant medication use and social engagement on the level of depressive symptoms at the time of initially meeting criteria for dementia. Method: Measures of social engagement, medication use, and depressive symptoms from 402 participants with incident dementia were utilized for the study. Proportional odds models adjusted for demographics were constructed with depressive symptoms as the outcome and social network size, perceived social isolation, and antidepressant medication use as independent variables. Results: Each additional person in the social network was associated with a lower depressive symptom score, odds ratio (OR) = 0.93, 95% confidence interval (CI) = [0.90, 0.97], p ≤ .01, and each unit increase in perceived social isolation was associated with a higher depressive symptom score (OR = 4.14, 95% CI = [2.94, 5.85], p ≤ .01). No association was found between antidepressant medication use and depressive symptom score. Discussion: Depression management at the time of dementia diagnosis should probably be directed toward increasing social engagement in older adults.