Autistic catatonia is an under recognised deterioration in motor function in autistic people, which most often occurs in adolescence. Catatonia has these features:
I can't move. Everything is a massive effort. I sit and think and wish I could do something, and nothing happens. I am cold, but I can't cross the room to close the window. I would like to watch TV, but it's turned the wrong way so I can't see it and I can't turn it towards me. I want to play a game...