The purpose of this study is to use magnetic resonance imaging (MRI) to take images of a participant's brain, and then apply an investigational way of processing the image, called Individualized Network-based Single-frame Coactivation Pattern Estimation ("INSCAPE") to measure participant's brain activity. This method uses a computer program to understand which parts of the brain communicate with each other and creates a map of the brain areas that are connected.

Participants being recruited in this study will include people planning to receive Transcranial Magnetic Stimulation ("TMS") for Major Depressive Disorder ("MDD"). Healthy participants are also being recruited. Images taken of depressed participants' brains will be compared to images of non-depressed participants' brains. Participation in this study will require three visits in which you will undergo MRI scans. The interval between each visits is about 3 weeks. Depressed participants will also complete mood assessments at several different intervals while they are receiving TMS for depression.

During each visit, MRI scans will require about 30 minutes of time in total. During the MRI scan, participants will need to stay still, relax, and keep eyes open in the scanner.