impetuous, impetus

Impetuous or impetuous means done quickly, without thought or care--
Calm down; don't make an impetuous decision you'll regret later.
He can be impetuous; he feels and then acts, without thinking.

Impetus or impetus means the driving or motive force--
The directors have offered a bonus, as an impetus to innovation.
A deadline can provide the impetus needed to finish a project.

Now that you know that, you can say--
"His last episode gave him the impetus to seek help for his impetuous behavior."