What is the best medicine for OCD. We have tried Zoloft, lexapro, wellbutrin, prozac. Side effects bad or did not work. Does Pristiq (desvenlafaxine) work for OCD?

SSRI's failed. So one SSRI may work when another does not. Keep trying. There is a new one called Brintillex which has much greater effectiveness in the reported studies. Also a Selegeline patch may prove effective.