[PuppyTailWags]

No, I don't think you understand ADHD. ADHD people do not behave in the way you describe when their attention "breaks". Their attention doesn't "break". Their attention is simply not regulated and so they will fail to perform tasks, which is not the same as having uninterest in those tasks which characterizes schizoid personality disorder. What you're describing as a checked out state is actually a reaction to frustration and distress that the ADHD person experiences as a result of being unable to regulate their attention long enough to perform tasks they want to do, which is not schizoid personality disorder characterized by not having a desire to form relationships and integrate with society. They're essentially completely unrelated conditions.

This also doesn't explain sensitivity to rejection or impulsive behavior typical of ADHD.

[kyleyeats]

Again, ADHD is the mask state, it's not SPD. It appears opposite of SPD in order to mask it.

The frustration and distress are both there in SPD too.

Schizoids are indifferent to praise or criticism. Do you see how that's the opposite of sensitivity to rejection? Do you see how the schizoid's listlessness is the opposite of ADHD's impulsiveness? The mask is a compensatory state, like the narcissist's super-confident persona.

[samatman]

You have no idea what you're talking about, and yet you go on, and on, and on, speaking complete nonsense.

Knock it off.

[kyleyeats]

Who are you?