but ebersol quickly realized something was wrong. >> no one knew what was wrong with me and there were sorts of hypotheses. >> home from school for months at a time, ebersol desperately needed an escape. and he found it in writing. >> i just started writing and i got lost in this world and identified with this character and it was just a way to keep me going. >> and then after several months, doctors finally discovered the cause of his symptoms. a rare form of lyme disease. at the same time, his scattered pages started to gel into a book. >> the book is called "the hidden world." it's about a main character who has a heart attack, slips into a coma and when he wakes up, he turns into a wolf in the hospital room. >> "the hidden world" was published last december with more in the works. ebersol says through it all, writing saved his life. >> you really just have to find something that can sustain you and keep you mentally strong. >> dr. sanjay gupta, cnn, reporting. >> "the human factor" is brought to you by cancer treatment centers of america. care that never quits. i missed you, too.ou

. >> at first he chalked it up to stress, but ebersol quickly realized something was really wrong. >>for months at a time, ebersol desperately needed an escape, and he found it in writing. >> i just started writing. i would get lost in this world and i identified with this character. it was just a way to keep me going while everything else in my life wasn't so great. >> reporter: then after several months, doctors finally discovered the cause of his symptoms, a rather form of lyme disease. at the same time, his scattered pages started to gel into a book. >> the book is called "the hidden world," about a main character who has a heart attack, slips into a coma. when he wakes up, he turns into a wolf in the hospital room. >> reporter: it was published last december, with more in the works and ebersol says through it all writing saved his life. >> you really just have to find something that can sustain you and keep you mentally strong. >> reporter: dr. sanjay gupta, cnn reporting. >> love to see a story where somebody finds a way to fight the challenge in their life. thank you for dr. sa