Mental disease is also known as a mental disorder or phycological disorder. It is a medical condition wherein a patient suffered from abnormal behavior that affects the lifestyle and daily living of a person. There are many kinds of mental diseases, here are six of them: Bipolar disorder, Acute stress disorder, Caffeine-induced sleep disorder, Generalized anxiety disorder, Major depressive disorder and Obsessive-compulsive personality disorder. There are some mental diseases that need to be treated and there are also some that does not need special attention or care.