deschavetarse

A colloquialism used across several Latin American countries (Argentina, Bolivia, Colombia, Cuba, Uruguay) meaning to lose one's mind or go crazy — the verb form of the classic idiom perder la chaveta, documented since at least 1780, comparing a person's sanity to the small pin (chaveta) that keeps a machine's parts from falling apart.

• Se deschavetó completamente después del divorcio. — He completely lost his mind after the divorce.
• No te deschavetes, todo tiene solución. — Don't lose your mind, everything has a solution.
• Dicen que se deschavetó por tanta presión en el trabajo. — They say he cracked from so much pressure at work.

It's colloquial and regional — in more neutral or written Spanish, volverse loco or perder la cabeza will be understood everywhere, whereas deschavetarse is tied to specific Latin American dialects.