If you go to the drug company sites like Pfizer, who makes Prozac and Eli Lily, who makes Zoloft, the first thing that pops up now is a disclaimer that taking these medications may increase suicidal thoughts during the first few months of taking them. HOWEVER, the studies did not detect an increase in suicidal thoughts for people over the age of 24.
I just know, for me, they're hard to get used to. But it is worth it in the end.