While this medication may seem useful & effective in the beginning, be careful. I've been taking this medication off & on for approx 10 years. I've found the longer I'm on the medication, the more addicted (mentally & physically) I am to it. I love the energetic, invincible feeling that it gives me in the beginning, however, I've found that I am more irritable & moody now too. I have gotten to the point where I feel I can't function without it, although it's lost its suppressant effect.