Min Yoongi got diagnosed with DID at the age of 19 when his mother took him to the hospital cause she thought he was going crazy (he wasn't) and she insisted on having him put into a mental facility, where he met Park jimin. Park Jimin has severe anxiety and depression and his mother was worried he'd hurt himself so she put him in the facility. The two boys became friends almost instantly when they met even though yoongi had to explain how DID worked, jimin had still insisted on staying his friend.