Neuroimaging techniques have been used extensively to compare brain structure and function between patients with, or at risk of, depression and control subjects. The goal of this work has largely been to identify pathophysiological processes in depression. However, progress in this field has been limited by the heterogeneity of patient populations, the use of small sample sizes, and an overreliance on case-control studies. These limitations have increasingly been acknowledged with recent work collecting much larger samples and employing a variety of study designs, including those able to stratify patient populations. This chapter reviews imaging studies in depression, highlighting both outstanding questions and promising recent findings.