One of my best friends is nearly 30 and she's developed anxiety over time. She uses a weighted blanket whenever the anxiety gets just too much for her to relax (I don't know what kind though-sorry
). For her it's relaxing that is the issue when it comes to sleep or sometimes just being in her apartment. Just providing an example that weighted blankets aren't restricted to age nor one's own particular issue (autism, anxiety, etc).
OP have you consulted your doctor by any chance? Just wondering if perhaps there isn't anything else that either could be contributing to the issue or whatnot.
What other things have you tried?
Has your son told you by any chance what types of things make it harder for him to sleep?
Is it that he can't shut his brain off so the thoughts just keep going and going?
Is it that for whatever reason he can't get his body to stay still even when he really wants to like perhaps a certain body part? I mention that because I have restless leg syndrome (RLS) that is minor but when it occurs it's difficult to sleep. RLS can impact children.
Is it something that happens at night that has him on high alert?
IDK just thinking out loud.