A deep look into how even the best athletes struggle with and persevere through mental illness.

In growing numbers, athletes are speaking up about their struggles with mental illness—including high-profile stars such as Michael Phelps, Kevin Love, Simone Biles, and Naomi Osaka. More disclosures are surely on the way, as athletes recognize that their openness can help others and inspire those around them.

In Mind Game: An Inside Look at the Mental Health Playbook of Elite Athletes, Julie Kliegman offers insight into how elite athletes navigate mental...