ADDers tend to excel at the next phase of zazen, which is generically referred to as thought labeling. During this period the inevitable drifting of attention away from breathing and onto the mental contents of the moment is not resisted. Both the dopamine and serotonin systems are affected in both short and long-term ways, along with a host of other key neurotransmitters and their synaptic webs. Through this simple action of allowing awareness and being present, an ADDer finds a kind of natural medication for their condition, although medicating or changing the person in a therapeutic way is not the intent of Zen. This other tenet of Zen practice is actually a kind of joke.
Zen practice is absolutely open.
It judges nothing in its field of awareness. The practice only acts to allow awareness to its maximum observational power by taking in not only yourself but all subjective conscious experiencing. It's not really important in Zen practice what you think, feel or do, what's important is that you pay attention to what you think, feel and do. Not the tightly constricted attention of narrow focus, but a soft open awareness of all that is. This observing self, though, is not really constructed, but revealed, as Zen practice illuminates the presence of an innate witnessing function to awareness.