When you say psychological novel I assume you are not just talking about a psycological thriller. I really enjoyed a book called Sybil. Its about a woman who has 17 different personalities and explains everthing that happened in her life that caused these personalities to emerge.
Another I enjoyed was Code to Zero by Ken Follet. Its starts with a man waking up in a bathroom with absolutely no memory of who he is or how he got there. As he goes throughout his day he realizes he is being followed and must discover who he is and why he has no memory.