It is already known that 1-(benzofuran-2-yl)-2-propylaminopentane or a pharmacologically acceptable acid addition salt thereof exhibits an excellent effect as an antidepressant, a psychotropic drug, an antiparkinsonian drug, and an anti-Alzheimer's disease drug. However, it has not been known at all that the compound is effective for the prevention or therapy of attention-deficit/hyperactivity disorder (ADHD). The present invention has newly found that 1-(benzofuran-2-yl)-2-propylaminopentane or a pharmacologically acceptable acid addition salt thereof is effective for the prevention or therapy of ADHD, and has been accomplished.
