Lily and Dunkin by Donna Gephart

A young teenage boy begins to transition into a girl with the aid of hormone blockers, while her new neighbor stops taking his mood stabilizers and ends up institutionalized.

This book contains;  alternate gender/sexual ideologies, bullying, commentary on suicide, derogatory terms, discrimination, gender dysphoria/transgender, hormone blockers, mental illness, profanity, sexual assault, and violence.