Hi! Thx for your information.  Don't know if you can give advice, but here goes:  I have sleep apnea but an being treated with Cpap machine which cures the snoring but not the continuous daytime sleepiness while I am driving which I do for a living.  Have also been taking provigil but am allergic to that, so...Caffeine no longer helps me as I have been using it for years at pretty high dosages.  Naps only help temporarily and would have to be napping practically all day to get rid of sleepiness.  I am a depressive person so I know that plays into the situation somewhat.  Am out of answers and could be out of a job. Would appreciate any suggestions or further resources. Thanks!