I am curious why the sleep study did not distinguish between these two? The sleep study should clearly show the nighttime awakenings diagnostic of sleep apnea or not. They give you a figure that is your average number of awakenings per hour. What was yours? FWIW, I took Wellbutrin and Vyvanse for ADHD, and these worked well for me. Later I was diagnosed with sleep apnea, and with appropriate CPAP treatment, I have been able to get off most of my meds and just rely on behavioral techniques to deal with the ADHD. My mood is also better. I now take just 100 mg Wellbutrin and only occasionally an ADHD med, when cognitive load is very high. This is usually less than a couple of times a month. I do find there is quite a bit of stigma against people who fall asleep during the day. This could be due to OSA, the idiopathic hypersomnia you mention, narcolepsy, etc. People just assume that you are bored, went to bed late the night before, etc. Sometimes I just tell people that I sometimes nod off and it doesn't mean I'm bored with you, it's just my sleep problem, and it is just momentary (at least for me). I guess I could take stimulants every day to prevent this, but is it worth the cost to my body? Now that I have CPAP, I am not falling asleep while driving anymore, so I am safe, but getting all the way through the day without nodding off at least a few times is impossible.

Good luck, shamon86. If you aren't sure about your nighttime awakenings from your sleep study, you should be able to get a print out from your sleep doctor that has all of your data.

ETA: if you do have OSA, it can take quite a while to see benefit from the CPAP, so don't give up. I think after 1 year of use, I was just edging into averaging 4 hrs a night of sleep with the CPAP.