I know antidepressants are to help you not feel depressed, so why are they prescribed to help with OCD?
In some people, there is a connection between two chemicals in the brain- dopamine and serotonin- with OCD-type behaviors. SSRIs affect how the brain processes serotonin and it seem to lessen OCD behavior in some people.
well... anti-depressants don't make you not depressed either. They take the edge off and bring up the lows a bit, but they (at least for the majority of people) don't make them happy, just somewhat less depressed
That's true of most medications- most don't get rid of the underlying conditions, they just help manage the symptoms.
In addition to that, I believe a rather large amount of people with OCD have co-morbid depression. As always, psychiatric medications work best with ongoing therapy. You can put a band-aid on a cut, but it won't make it disappear. In other words, pills can alleviate some symptoms for certain people, but the condition is still there. Therapy can help a person learn how to cope better through the use of specific techniques.
Co-morbid basically means co-existing. It could either mean that a person has two conditions at the same time, but neither as a result of the other, or that one of the conditions is a result of the other.