HappyHead by Josh Silver

We are in an epidemic. An epidemic of unhappiness. 

Friends, here is the good news: HappyHead has the answer.

When Seb is offered a place on a radical retreat designed to solve the national crisis of teenage unhappiness, he is determined to change how people see him and make his parents proud. But as he finds himself drawn to the enigmatic Finn, Seb starts to question the true nature of the challenges they must undergo. The deeper into the programme the boys get, the more disturbing the assessments become, until it’s clear there may be no escape...

Squid Game meets They Both Die at the End, this nominee for the 2024 Carnegie Medal for Writing is a must-read for fans of The Hunger Games.