Intrusive thought
Antidepressants which have been shown to be effective in treating OCD include fluvoxamine (trade name Luvox), fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and clomipramine (Anafranil). Although SSRIs are known to be effective for OCD in general, there have been fewer studies on their effectiveness for intrusive thoughts. A retrospective chart review of patients with sexual symptoms treated with SSRIs showed the greatest improvement was in those with intrusive sexual obsessions typical of OCD. A study of ten patients with religious or blasphemous obsessions found that most patients responded to treatment with fluoxetine or clomipramine. Women with postpartum depression often have anxiety as well, and may need lower starting doses of SSRIs; they may not respond fully to the medication, and may benefit from adding cognitive behavioral or response prevention therapy.
Excoriation disorder
SSRIs have shown to be effective in the treatment of OCD, which serves as an argument in favor of treating excoriation disorder with the same therapy. Unfortunately, the clinical studies have not provided clear support for this, because there have not been large double-blind placebo-controlled trials of SSRI therapy for excoriation disorder. In fact, a meta-analysis of pharmacological treatments of excoriation disorders, it was found that Selective Serotonin Reuptake Inhibitors (SSRIs) and lamotrigine were no more affective than a placebo for longterm effects. 
Review of treatment of excoriation disorder have shown that the following medications may be effective in reducing picking behavior: doxepin, clomipramine, naltrexone, pimozide, and olanzapine. Small studies of fluoxetine, an SSRI, in treating excoriation disorder showed that the drug reduced certain aspects of skin picking, as compared to placebo, but full remission was not observed. One small study of patients with excoriation disorder treated with citalopram, another SSRI, showed that those that took the drug significantly reduced their scores on the Yale-Brown Obsessive Compulsive Scale compared to placebo, but that there was no significant decrease on the visual-analog scale of picking behavior.