Delirium is a very well written novel about a society that views love as a disease. I enjoy it every single time I read it, and I eventually bought it because I knew it was worth reading multiple times. I wasn't able to put it down when I first got it from the library, and I often stayed up way later than when I go to sleep reading it.
The main character, Lena Haloway, is very easy to relate to, as many characters are in young adult fiction, or any fiction really. She often feels like an outsider and is easily affected by what others say. Everyone experiences that feeling whether it's every day or once in a while.
I also thought that the love story between her and Alex was very beautiful. It opened Lena's eyes to everything she had been missing as a young child, and taught her that love IS NOT a disease, no matter how much heartache it can bring you.
There is one moment though where Lena and Alex are together where he takes off her shirt and describes her as beautiful, which helps Lena in a way considering that she is self-conscious about her body, as every girl is from time to time. Even though there is somewhat of a good side to that, it still isn't moral for a man to see a girl without a shirt on when they aren't married. The scene doesn't go farther than that though and is pretty tame.
The language isn't too common, but f*ck you is said twice in one scene, but isn't said any more than that. Other minor words are scattered throughout the book.
Also, in one scene, whiskey is mentioned and it is implied that teens are drinking alcohol, but isn't major, and Lena doesn't take part in it.
The novel isn't very violent, considering it's mainly about love and romance, not something like war or a plague.
Overall, this is a really good book and in my eyes, is worth swallowing down the few instances of immorality.