Amphetamines (Adderall, Vyvanse, Dexedrine) and methylphenidate (Ritalin/Concerta) are powerful stimulants. They'll give you plenty of energy and ability to focus. This explains why they are rather commonly used by students and other folks.

The life changing aspect, for me, is that they can sometimes break me out a depressive episode. I'll have days sitting around, desperately wanting to work on something, but ending up watching TV, eating, and sleeping. This of course makes me feel bad about having not done anything, which just worsens the situation.

Stimulants can change that. Apart from the energy and focus, they often propel me into doing something. I've taken them, feeling pessimistic and resigning myself to another day of sitting around. But they'll kick in, I'll pull up my laptop, and code 8+ hours straight. That bit of progress alone is enough sometimes to break out of the depressive streak and get on with things.

But please, before starting any medications, make sure you have a psychologist to monitor you. Do not underestimate suicidal thoughts. The closest I've been to suicide is when I tried out an anti-depressive. Medication that can pull you out of depression can also provide you the energy and willpower to follow through with suicide.