"a doctor prescribed this for hypertension, based upon his premise that mine was caused by anxiety. that was almost 40 years ago. after arguing back and forth, i agreed to take it on a limited basis. now i use 2 mg, 4 times a day as needed, but only before lying down and never when i will be driving or need to otherwise be alert. it is a great help when i do get overly anxious, as i am prone to do. i consider it useless if i am up and about."