This chapter provides an overview of the rapidly evolving economics literature on mental health, focusing on research published since 2015. This literature has grown substantially, reflecting the increased recognition of the prevalence and economic costs of mental illness, declining stigma, and the growing availability of data on mental health. In addition to the economic costs of mental illness, the review focuses on four broad classes of determinants of mental health: endowments, economic resources, education, and trauma. We also examine the determinants and effects of mental health treatment. Finally, we discuss how certain features of mental illness, including its episodic and recurrent nature, pose challenges for the canonical health capital model.