Adult AD/HD Regulating Alertness

One of the things that always puzzled me when my son Josh was younger was how he tended to be extreme in his degrees of alertness. He was very hyperactive much of the time, but when I managed to get him to sit down at the table or on the couch to do school work he became downright lethargic. He'd go from spinning around like the Looney Tune Tasmanian Devil one minute to propping his head on his hand and looking groggy the next. It's as if he couldn't regulate himself to anything in between the two extremes. Now Josh is a young adult, and his AD/HD sister is in her late teens and I see the same issue of regulating attention manifesting in a slightly different way. My AD/HD husband Scott, my son, and my daughter all tend to fall asleep if they are sitting still listening to a lecture. Keep in mind they are not sleep deprived, so I don't think lack of sleep is what's causing it. Every single week in church, they are fine during the music portion of the service. They are fully awake during the meet-and-greet time. But once the sermon begins and they are sitting still and quiet, they close their eyes and fade away. At first I thought it only happened at church, but that's not the case. It happens any time they are required to sit quietly in one spot and just listen. I recently attended a meeting with Scott and Josh to hear a speaker discussing issues that affect adults with AD/HD. In a room with about 20 people, I looked around and saw that only Josh and Scott were in the "I'm not sleeping but my eyes are closed and I LOOK like I'm sleeping" state. So I wonder if this is something many adults with AD/HD struggle with, or if my family's manifestation is somehow unique. When Josh has a fidget ball with him, he is better able to regulate himself and stay awake and alert. When Scott takes notes, it helps him focus. When Beckie doodles, she attends better to what is being said. Yet if none of these strategies are implemented in time, they drift away and miss many points from the presentation being offered to them. They need to plan to use the strategies prior to finding themselves in an attention-challenging situation, but planning does not come naturally for them. By the time the need for a strategy becomes clear they may already be drifting away.