narcolepsy
"Modafinil has changed my life.  I am 50.  I have probably suffered with narcolepsy for about 35 years.  It has worsened with age.  I was diagnosed 15 months ago.  Initially prescribed dexamphetamine, initially I thought it was marvelous but I eventually realized it made my life almost unbearable.  I have been taking Modafinil for 6 weeks, the first 2 weeks were difficult, mainly due to stopping the dex, since then life has slowly improved to the point where I have never felt better.  Everything has suddenly become easy.  I never realized how easy life can be.  I wish I could meet the man who first produced modafinil to say "You have changed my life, THANK YOU.  XX""