Even when they work well there will be some collateral damage with stimulants. I was a great employee on them, but I was a shitty, narcissistic friend. The focus many people get from stimulants is an inward focus, which makes it easy to get things done but hard to empathize with other people. As a result I didn't have many friends, and once I started wanting more out of life I realized the stimulants were holding me back from personal growth. The inward focus clouded my ability to understand why people didn't like me -- I couldn't make enough space for another person to even see why people didn't want to be around me.
I'm not saying that stimulants don't help (they totally do) but you should understand what you want out of your life and how that aligns what you get out of the drugs.