Autistic burnout

Hi yes he is diagnosed. He seems to shut down for days at a time ,stays in bed,  doesn’t speak, then one day will get up for a few hours as if nothings happened. He won’t talk to me about it but it worries me 

I don’t think that’s burning out.. my opinion ;-) I would generally only burnout until the next sleep. 
Are you sure he hasn’t got a “obsession “ whilst in bed.. Xbox, laptop, tablet? Talking to a lady friend? 
he’s 15 and I don’t think he’s burning out.  But I wouldn’t know I’m just showing you different ideas.. my opinion again, if I stayed in bed, this would be a depression issue. My burnouts have mega physical issues.

I don’t think that’s burning out.. my opinion ;-) I would generally only burnout until the next sleep. 
Are you sure he hasn’t got a “obsession “ whilst in bed.. Xbox, laptop, tablet? Talking to a lady friend? 
he’s 15 and I don’t think he’s burning out.  But I wouldn’t know I’m just showing you different ideas.. my opinion again, if I stayed in bed, this would be a depression issue. My burnouts have mega physical issues.

That makes sense,  but when I tell his Psychiatrist they say he s not depressed. I suppose I just need to be there for him for when he’s ready to engage. 
It’s very helpful  talking to someone who is autistic, thank you. 

1. The doesn’t speak thing.. I don’t speak much. An people have branded me bi-polar most of my life (39) turns out I’m ASD OCD