Having followed this disappearance religiously back a few months ago, I find it incredible there is still no leads or case progression.
Nobody just vanishes for this length of time. I believe there are only two possible explanations as to what happened to Leah.
1. Either she is still alive somewhere and is being held captive against her will after being kidnapped.
2 Or she was attacked and killed at, or around the day she went missing and the remains have been well disposed of.
If Leah had committed suicide she would have been found by now, so have to agree with the majority of you and suspect foul play. Unfortunately, it looks like unless the purpetrator slips up at some point (or conscience gets the better of them:- it appears their tracks have been well covered.
Without evidence of a body though, we have to assume she could still be alive, and I for one hope that she is and is waiting for an opportunity to make for the escape!.
Very sad this case remains unsolved.