Dipenhydramine is not great long term or regularly for sure. I was using it way too often to sleep and then I also used that when I attempted suicide... I took so much that I was drowsy for two weeks. I had to have my mom come up for basically a week during that time to make sure I was okay and whatnot.
I generally avoid dipenhydramine because, of course, it reminds me of my suicide attempt. But besides that, I'd also avoid them as there are so many other options. For sleeping I was able to get prescription medication that is much more effective anyway.
Good link though, because a lot of people just take meds they can buy anywhere just whenever they want like it isn't an issue at all when, in fact, it can be a bit of an issue.