<qa>  What is the atypical antipsychotic drug that acts as an antagonist at 5-HT2Risperidone is an atypical antipsychotic drug that acts as an antagonist at 5-HT2A2C and D2 receptors Chouignard et al, 1993; Marder Meibach, 1994. In its serotonergic activity, risperidone resembles both the atypical antidepressant and 5HT2-antagonist nefazodone Bakish et al, 1993 and a 5HT2-antagonist ritanserine Lima Moncrieff, 2000; Preskorn 1995. Nefazodone treats anxiety symptoms and induces less agitation than other reuptake blockers Fawcett et al, 1995 while ritanserin shows effectiveness in treatment of dysthymia in clinical trials. Moreover, risperidone increases release of dopamine and norepinephrine in the prefrontal cortex Zhang et al, 2000, an activity that in other pharmacological agents is associated with their antidepressant, anxiolytic, and antipanic properties Thase, 2002. 