The closest matches I have found at this point are not Maddens, they are Larkins, Trainors and Kellys. All are descendants of the Ui Maine (or Hy-Many). Madden is the anglicized version of Ó Madaidhin. Madudan, the son of Gadhra Mor was supposedly the founder of the sept and the Kelly's were formed by his brother. The sept was part of the Ui Maine based in east county Galway, but a group broke away and settled in Clare and Limerick in early times.
DNA results suggest a connection to other Ui Maine descendants is about 97% likely within the last 24 generations. If one uses societal norm of about 25 years per social generation that would mean within the last 600 years...or 400 years less than the era (about 1000) when Madudan lived. This suggests a lot of intermingling within those years.
As I can only trace our ancestry back six generations from the donor of this sperm (or about 200 years from today) the likelihood of making any connection other than that we are Ui Maine is unlikely. But what fun anyway. So here are the results and links for more information.
Results - R1b1a2a1a1b4 WAMH and 21 (49 marker) and 17 (51 marker), P being L21+, DF23+, Z2961+ . Now don't ask me what all that means, although I have some inkling, the links below will explain it much better.
Missing Generations 31-41
FamilyTree DNA - Madden Project
R1b (all subclades)
RL21+ (mainly Celtic - must test + to join)
FamilyTree DNA - Kelly Project (open to Kellys and that occasional close match!)
look for group 14 Ui Maine.
Dr. Tyrone Bowes FamilyTree DNA Presentation at WDYTYA 2013
Dr Tyrone Bowes - Pinpointing a Genetic Homeland