I just read in my psychology textbook that even when adolescents reject their family’s values, they often come back to them in the end (and this was talking about Goyim who don’t have Toras Emes like we do.
OTD has always existed to some extent, but there is a specific plague today of OTD. Most of these kids need psychological help and when/if they work on that, they do come back. Of course, it is not always easy for them to get the help they need, since it is not a simple thing, and unfortunately, many of them OD meanwhile. But the point is that most do want to come back and if their issues are worked out, do come back. No sane person would leave Yiddishkeit by choice!!! We are so lucky to have the Torah and anyone who leaves it has some kind of issue that needs worked out.