You've Come So Far

As we all know, Percy Jackson was abused as a child by his of-the-time step dad, Gabe. The man was nasty and he left a scar on Percy. Physically and mentally.
It's been nearly 6 years since Gabe's death. Percy had been doing so well, he was coping, he was moving on.
But he got a call that sent him running to help. That Leo Valdez had fallen into depression. That he was talking about suicide.
Gabe beat depression into Percy's brain, and that's something he never got over. He still remains depressed, no matter how well he hides it, Percy still wants to kill himself. But he won't.