This document discusses the potential for quantified self technologies to improve mental health. It begins with definitions of quantified self and an overview of the prevalence of mental illness. Sections then discuss specific apps that can be used for mental health tracking, issues around data reliability and patient empowerment, and security and responsibility considerations. The discussion section raises points about the role of quantified self in psychiatry and perspectives on its future use. Overall, the document examines both benefits and risks of using self-tracking for insight into mental health and changing behaviors.