self-destructiveadjective
us/ˌself·dɪˈstrʌk·tɪv/(of behavior or actions) likely to harm or kill you:
Freedom is not an excuse to indulge in self-destructive behavior.
self-destruction
noun [ U ] us/ˌself·dɪˈstrʌk·ʃən/
Barrymore was a brilliant actor bent on self-destruction.