Additional Study Information: In this research study, you may receive treatment using flavanols to augment a already prescribed antidepressant drug. Flavanols can be used to augment many different antidepressants and augmentation may help with symptoms of depression by increasing the availability of specific chemicals in the brain. The study may place patents on a placebo track due to which patients may not be aware of the medication that is prescribed to them. A placebo is a sugar pill. The purpose of this study is to determine how flavanols affect depression treatment. Participants in this study will also undergo Magnetic Resonance Imaging (MRI) in order to investigate the brain responses associated with depression.