Neuro-affective Response to Light in Depressed Adolescents and Young Adults

The goal of this neuroimaging pilot study is to understand developmental differences in the impact of therapeutic wavelength light (blue light) versus a non-therapeutic wavelength (red light) on emotional brain function in depression. The main questions this study aims to answer are:

* Does acute exposure to blue light (vs red light) stabilize emotional brain function in depressed individuals? * Are stabilizing effects of blue light (vs red light) stronger for blue light in adolescents than young adults?

Participants will complete:

* A magnetic resonance imaging brain scan, in which we will examine the effect of blue versus red light on emotional brain function at rest and in response to rewards and losses. * A pupillometry test of sensitivity to blue vs red light * Clinical interviews and surveys * Screening measures for drug and alcohol use, MRI safety, and current pregnancy \[if relevant\] * Home sleep tracking with sleep diary and actigraphy for one week