The frequent comorbidity of anxiety and depression, particularly among elderly, is widely recognized by clinicians, but the debate continues as to whether the combined diagnostic designation is merited. This article reviews the debate over the mixed diagnosis, discusses treatment implications, and reviews a small treatment study undertaken with elderly patients. Ten community-dwelling, older adults diagnosed with generalized anxiety disorder and subsyndromal depression (n = 6) or generalized anxiety disorder and major depressive disorder (n = 4) were started on a 12-week, open-label trial of nefazodone. Clinicians' ratings on the Clinical Global Impression of Change and patients' self-ratings of symptoms on the Beck Depression Inventory and the Beck Anxiety Inventory identified statistically significant gains in patients' overall pre/post functioning. Nefazodone was efficacious in symptom alleviation in patients with comorbid anxiety and depression. Further double-blind, randomized investigations with newer antidepressant medications are required to extend these preliminary findings with nefazodone.