anxiety
"I've been on 5mg of Diazepam (Valium) for several years now.  My prescription calls for 2 pills/day per month.  The 60 pills usually last me 4-6 months, so I don't need to take them all the time.  When I get a panic attack 1 pill usually takes care of it. If not, I take another one a few hours later.  I have tried many anxiety meds, this is the only one that seems to work."