The Pact by Jodi Picoult (2006, Paperback, Reprint)

In this book, two teenagers make an apparent suicide pact, but one survives and goes on trial for murder. Through flashbacks, we discover the reasons behind the wish for suicide, but even so I can't say I was ever fully persuaded, nor did I think there wasn't ample time for intervention, nor did I think the event (suicide) itself would have played out as it did. The book also focuses heavily on the parents who have been next door neighbors since before the kids were born and who are split apart by the death. The book is gripping and highly engaging - even though it has been a long time since I was that age, I "got" the reasons that a teen might choose suicide and not understand the permanence of the decision. And yet, a lot here was quite implausible and finally just didn't fit together so I can't give my highest recommendation.