anxiety and stress
"I have been on fluoxetine 20mg for six months.  It took about 8 weeks to notice any positive mood changes.  After a few weeks of starting it I began to feel like I was living in a fog and had a difficult time concentrating but that eventually went away and turned into optimism and feeling great.   Please give it a couple of months to work.  It takes time to kick in.  After 8 weeks I felt good and happy for a while but recently have relapsed into anxiety and depression again.  My MD has now upped my dosage to 40mg.  I am hopeful I will get the happiness and optimism back again soon from the higher dose."