Thirteen Reasons Why is wracked with emotion, and can be hard to read the first time, purely because it has the power to devastate the reader. But do not be taken in by this- though the message is good, characters developed, and plot well-timed and executed, I find that I like it less and less each time I read it. After reading, you are supposed to feel sympathy for and be understanding to people with suicidal thoughts. I know people who have attempted suicide, and I feel for them and understand their struggles, but I just could not stand Hannah. Humans need love and attention, so I understand why Hannah put herself in the position to be hurt again and again, but she went looking in all the wrong places. It's an accurate portrayal- often teens don't go to parents or counselors for help - but infuriating (perhaps this is Asher's intention). Hannah's suicide wasn't drawn to be inevitable, which made it all the more tragic tragic, but it was romanticized. Hannah seemed almost a hero for sticking through these trials leading up to her suicide, and Clay loves her through it all. Suicide in and of itself doesn't seem a crazy or dark option- merely one that cannot be taken back.
There is a more graphic scene near the end, when Hannah allows a boy she doesn't like to fondle her. Teens drink and party often.