depression
"I've taken nuvigil off and on for about a year, along with 20mg lexapro. I take it as needed for depression and daytime sleepiness (I was falling asleep while driving). I find that it makes me agitated and irritable if I take it every day, so I only take 150mg when my depression is causing extreme lethargy and lack of motivation. 

When I do take it, it usually works within an hour. I am motivated, focused, and productive on this medication. It even helps with my social anxiety, and I find that I'm more cheery and outgoing. I'm more talkative too, but in a good way - not in a manic way. 

The problem? It wears off after 6-8 hours, sometimes leaving me with a headache. Overall, however, it has been a big help to me!"