How does intuniv act as a solo treatment for adhd?

Mechanism unclear: Intuniv is a once-a-day version of Guanfacine (also called tenex), which is a high blood pressure medication that works through the norepinephrine system. Exactly how it works is unknown--which really is true of most medications we use in psychiatry--but its efficacy has been demonstrated in kids, adolescents, and adults. It's a nonstimulant and must be taken daily but provides 24-hour coverage.