The Difference in the Mechanism of Action Between Two Brands of Dexamfetamine in Adults With ADHD

The goal of this clinical trial is to compare in the pk/pd profiles of magisterial dexamfetamine and Tentin in adults with Attention Deficit Hyperactivity Disorder (ADHD). The main question\[s\] it aims to answer are: Q1: is there a difference between pk/pd profiles of the two forms of dexamfetamine? Q2: how does the pharmacokinetic variability influences the objective and subjective (side) effects experienced by adult patients with ADHD? Participants will: * take the Quantified behavior Test for analysis of objective effects. * undergo blood sampling for analysis of the plasma concentration of dexamphetamine. * undergo blood pressure and heart rate measurements. * fill out 4 types of questionnaires. Researchers will compare the outcomes between magisterial dexamphetamine and Tentin use in a crossover setting.