I think there's a strong possibility he went missing deliberately and that his family knew that, hence the late missing persons report. They probably expected him back eventually, but knew why he'd gone. It could also explain why they didn't take any risks continuing the search overnight
Whether he's missing and safe or not now is another thing, and of course it doesn't help the anxiety and dread the family will be feeling.
Whatever the truth it, I can guarantee we only know a tiny part of it. They're not going to report on family issues or his MH, or at least you'd hope not.