Major depressive disorder (MDD) is a highly prevalent, chronic and/or recurrent condition with substantial morbidity and mortality. It is one of the leading causes of disability worldwide. Despite significant advances in pharmacological treatment for depression over the last two decades, a significant proportion of patients (10-20%) are resistant to currently available treatment. The development of new effective treatment for depression is limited by the fact that MDD is a heterogeneous disorder with subgroups based on variations in etiological factors and treatment response. Functional magnetic resonance imaging (fMRI) approaches offer promise in the prediction and evaluation of clinical response of antidepressant treatment.