*****FROM ABC NEWS MEDICAL UNIT*****
Hi M_NAME and thank you for your question. Here is an answer from Bruce Cohen, M.D., Ph.D., Director, Shervert Frazier Research Institute, McLean Hospital:
Symptoms and signs of illness can change over time, and with such changes, a new diagnosis may be appropriate. For example, it is not uncommon for someone who has experienced a depression to experience a manic episode later in life. Thus, a diagnosis of major depressive disorder may change to bipolar disorder. Similarly, early symptoms of what will become schizophrenia may at first suggest a diagnosis of major depressive disorder, bipolar disorder or borderline personality disorder.