Hello Adrian,
I have also posted here before with a specific question about ADD/ADHD. (My fiancee has ADHD.) Concerning your question about Paraliminals, I am not sure if they would work properly on someone with ADD, as that person's brain functions a little differently in the frontal lobe. Hence your observation that a specific Paraliminal didn't seem to work for you. They usually work right away and without any question.
Interestingly, the Paraliminals have a note on the inside of the tape packaging that advises people to consult with a physician or mental health professional for advice on using the tape if you have any neurological, respiratory, or severe mental and/or emotional problems. This would seem to include ADD.
For obvious liability reasons, I don't believe that any representative or employee of LSC will comment on how best to use Paraliminals for someone with ADD.
It also appears to me that Paraliminals CANNOT correct problems that stem from a disorder that is physical in nature.