TREPINATION - The basic theory behind this "therapy" holds that insanity is caused by demons lurking inside the skull. Boring a hole in the patient’s head creates a door through which the demons can escape, and – viola! – out goes the crazy. Through the years, archaeologists have uncovered skulls marked by a carefully cut circular gap. From the Neolithic era to the early 20th century, cultures all over the world used it was way to cure patients of their ills.