Scott Spencer's novel, 'Endless Love'
The novel "Endless Love", which was written by Scott Spencer in 1979 is extremely good. The movie was loosely based on the book. For instance, the book begins in the 1960's and ends in the late 1970's. It's story is linked more to mental illness rather than a sappy teen romance. It is told by David who has a total obsession over his girlfriend AND her family.
The book goes into detail about David's experience in the mental institution. Unlike the movie, he's sentenced there for a number of years and continues to obsess over Jade, whom he hasn't seen for a very long time. Its kind of sad and dark b/c you feel sorry for this man who can't function with a job or live his life w/o obsessing over this girl and her family.
He nevers really recovers by then end of the novel. You just assume he's a sick person with serious issues. Jade does love him, but is able to move on with her life and marry someone else. She can't handle the fact that David is somewhat responsible for her father's death. Then there's the graphic, 10 page sex scene between the lovers after they reunite in their early 20's. I was shocked to see this after seeing the sappy movie. Later on, Jade becomes a lesbian for a short while as well.
With all of this information, you should realize this book is more realistic and covers more of life's problems than the cutesy movie. I read it when I was 16 and it was a very complex novel. I'm 22 years old and its even better now than before. I highly recommend it!! You can purchase it on Amazon.com.