evelyn, the inability to write on a topic which isn't of innate interest... may well just be a maturity issue; one which is related to executive function.
It's only been in the past year or so that my DD has been able to do this with any kind of efficiency at all. She's almost 14. Up until now, we suspect that pretty much ANYTHING else flitting through her brain or going on around her would take precedence over a task she didn't want to do or found boring (for any reason).
Pair high ability with low-value/low-interest tasks in a child without fully developed executive function, and OF COURSE that looks like any number of other problems, basically.
My DD has no underlying problems as far as we have ever been able to determine-- it's 110% situational. She has to be motivated to do it, and that is just the bottom line.
What does his output/processing look like to you when he IS working on something which interests him and offers him intrisic reward?
