Dharma,
I'm going to give you my full view on the ADD thing. Some things may be helpful, some may not. Some may even make you mad, and some may not apply to you at all, but if any helps I'll be happy.
My daughter fits an ADHD profile 95%. I had three doctors tell me that she is ADHD and one *insisted* that I give her meds. I read some, read more, and started questioning everything that I read. What I found made me sad. Most *normal* kids can fit the profile of ADHD. The number of children being treated for ADHD is absolutely shocking. ADHD diagnosis is usually prompted by a teacher who is tired of "dealing" with a difficult child. Here are some random thoughts about it in no particular order or reason:
1) FOOD ALLERGY!!!! (OK, this one is #1 for a reason). I found out that the massive amounts of food preservatives, sugars, artificial ingredients and hormones cause children with sensitive nervous systems to have symptoms. This was the #1 thing that I found with my daughter and it ended up being dairy. She is OK with organic, but give her "regular" massed produced and watch her turn into devil child. Add that to a nice serving of ultra-blue fruit snacks and you barely can get her to sleep. I had doctors tell me that it couldn't be. I then was talking to an associate from another company who's tag line is "like a geek on dairy". He is also allergic to dairy, even as an adult. He likens drinking a glass of mass produced milk with drinking a 4 shot espresso. His Mom was told that he was ADD as a child but refused to medicate him. She eventually found a doctor that has been studying the effects of dairy on children.
2) Environment. Something that you send made me cringe- "since the start of the school year, Jake has consistently done this". Why just this year? What changed? (Well, I know some, but I am sure that there is more). What is his classroom/teacher like?
3) Attention. Things have changed in your life. He may be under stress and needs more attention.
4) Boredom. Kids who are not challenged lash out in different ways. As an example, my husband failed a grade because he didn't do homework and ignored the teacher. Why didn't he do it? It was boring and he didn't see the point, so he simply didn't pay attention.
5) It may simply be his personality. Some children are high strung. You meet people like this all the time, and you usually view them as "high energy". They usually end up being fairly successful, but had "issues" when they were children.
6) Some children have sensitive nervous systems that will be triggered by different things (This is actually what they expect colic is). My daughter is this way. Too much noise, too much stress, too much anything will turn her into a crazed child. It's the way she is, and she is growing and learning to deal with it.
7) I have a cousin who was having her daughter treated for ADHD. Come to find out the daughter was actually hypoglycemic. After a proper diet, the ADHD signs went away.
Don't know if any of that helps, but hopefully ot will help you question *everything* that the doctors say, and maybe have them look into other health issues that could be the underlying cause of his issues.