insomnia
"I've had severe insomnia for over three years and it was not uncommon for me not to sleep for two or three days in a row.  After trying several other prescription medications, none of which worked, my Doctor placed me on Seroquel.  I slept well but the side-effects were awful.  It gave me severe headaches and made me feel like a total zombie the next day.  However after the first week or so I decided to take one-half the amount prescribed and I still got the sleep but the side-effects disappeared. After three years of bad insonmia, I don't know what I'd do without it.."