Thanks, Pashuta Yid. Very powerfull.
Other than focusing on the reasons for going off, which are as many as there are people, we can focus on the routes to going OTD. Either Emuna starts to go or interest in the outside world gains a bigger and bigger place in the mind or the Taava.
Each of these things target different situations. What makes someone susceptible to any of these could be anything, but the challenges available are pretty specific, and can be addressed. The Gemara does say about the Taava of Arayos that it takes the person till the end. It doesn’t say about Lashon Harra that thinking about it is worse than doing it.