<s>[INST] I have a 44 yr old nephew with autism. He takes anti seizure medications and has for years. He does not talk, is quiet and has never caused any trouble. In the last week, he walked away from home, has been talkative and destructive. Why the sudden change. He went today for a brain scan and nothing was found. He also had a nuclear med. test but not results yet. [/INST] Hello, The patient most likely developed mood disorder during which it is common for them to move out, become aggressive, violent, demanding, difficult to control, and it seems that the person has changed completely by someone else. It is not uncommon presentation in patients with autism. However, there is no need to panic. You may take him to his psychiatrist and start the required antipsychotics.  Chat Doctor.  Till then please take care that he doesn't harm himself or others near him. Donor become violent or lose your temper on him as he is doing all this due to another psychiatric problem. Hope the reply is useful. </s>