I was on Paroxetine (Paxil, I prefer using the chemical rather than brand name, which are different for each country) for just over three years. I did feel better during this time, but I don't know whether it was the medication or just things in my life improving.
I started feeling bad again and I was slowly taken off it, then slowly started new medication (Venlafaxine & Mirtazapine). When taken off the Paroxetine I felt a lot better. During the past year I feel my life has taken a downturn. If what I am on now is supposed to make me feel better, I shudder to think what I would be like without it.
For me it is just too difficult to determine whether medication is making any difference. Only an unbiased third party can make that observation. But I would recommend anyone with problems get help, if it doesn't work at least you know you tried. When someone gets a disease sometimes treatment works and sometimes it doesn't. I believe this is the same for either physical or mental illnesses.