My almost 6 year old DS ADHD possible ASD has been going through a big "don't want to be alone" phase for the last 6 months. It started when we moved into a newer bigger house, and his freaking out isn't so much a tantrum, but more sounds like he's being silly. For a long time, i thought he was just being silly. Like, "okay, mommy, we're going to hold hands and walk to the kitchen together" and "you've got to hold my hand because i don't want to go alone, tee hee". That kind of stuff. He's our only child, so we'd either just go with or he'd wait around with us and not go to that part of the house. After a few months, i finally figured out he was actually serious -- he really didn't want to go to the other side of the house alone. Interestingly, i don't think my DS has anxiety at all - i posted a question on this forum several months ago to see if anxiety in young boys sometimes looks like something else, because other than this issue, my DS comes across as the opposite of anxious. I googled the separation anxiety thing, and it's apparently a very developmentally normal phase for 5-6 year olds, so i've just let it go. It already seems to have faded since it's peak a few months ago.