Dr. Thigpen is a fictional character from the book "Sybil," which tells the story of a woman with dissociative identity disorder. The character is a psychiatrist who works with the main subject, Sybil Dorsett, to help her understand and integrate her multiple personalities. In the narrative, Dr. Thigpen employs various therapeutic techniques to uncover the traumatic experiences that led to Sybil's condition. The book highlights the complexities of mental health treatment and the importance of empathy and understanding in the therapeutic process.