We examined associations between treatment modality for depression and morbidity burden. We hypothesized that patients with higher numbers of co-occurring chronic illness would be more likely to receive recommended treatment for depression with both antidepressant medication and psychotherapy.Using a retrospective cross-sectional design, we analyzed data on 165,826 people over 16 years from 2004 to 2008. Using a single multinomial logistic regression model, we examined the likelihood of treatment modality for depression: no treatment, psychotherapy alone, medication alone, and psychotherapy and medication. We examined the following predictors of therapy: (a) morbidity burden; (b) five specific chronic conditions individually: diabetes mellitus II, coronary artery disease, congestive heart failure, hypertension, and chronic obstructive pulmonary disease or asthma; and (c) sociodemographic factors.The likelihood of any treatment for depression, specifically psychotherapy with medication, increased with the number of co-occurring illnesses. We did not find a clear pattern of association between the five specific conditions and treatment modality, although we identified treatment patterns associated with multiple sociodemographic factors.This study provides insight into the relationship between multimorbidity and treatment modalities which could prove helpful in developing implementation strategies for the dissemination of evidence-based approaches to depression care.