The co-occurrence of drug addiction in adults with attention deficit hyperactivity disorder (ADHD) is very common, but its etiology remains largely unknown. Therefore, animal models to study this kind of psychiatric comorbidity are needed. The Spontaneously Hypertensive Rat (SHR) strain shows neurochemical and behavioral characteristics which make it a suitable model of ADHD. Compared with their normotensive controls (Wistar-Kyoto) and with some other rat strains, SHR rats drink more ethanol and are more sensitive to its anxiolytic/stimulant effects. They also show increased sensitivity to psychostimulants, opioids and cannabinoids. Furthermore, chronic treatment with methylphenidate, the first-choice drug to treat ADHD, during adolescence, changes the ethanol...
