In the absence of certain consistent biomarkers, the diagnosis of autism is based on well-defined basic behavioral symptoms: abnormal social interactions and social communications, and repetitive and/or restricted behaviors. interests. Many medications, including fluoxetine and risperidone, have been used to treat symptoms associated with autism. Risperidone, an atypical antipsychotic that blocks D2 and 5HT2A receptors, has been approved by the U.S. Food and Drug Administration (FDA) to reduce repetitive behaviors and self-injurious behaviors in children with autism. Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), is being evaluated by the FDA for anxiety and repetitive behaviors in people with autism. Serotonin dysregulation is a theory about the etiology of autism (reviewed by Pardo & Eberhart, 2007) and has been associated with comorbid behaviors associated with autism such as depression, anxiety, mood , impulsivity, and aggression (reviewed by Soorya et al., 2008; West et al., 2009). Both risperidone and fluoxetine act in the serotonergic system. Risperidone antagonizes the serotonin 2A receptor and fluoxetine blocks the serotonin transporter, thereby increasing the amount of serotonin available at the synapse. Animal models are a useful tool in the search for pharmacological treatment for the core symptoms of autism. One approach is to select inbred strains of mice that exhibit behavioral characteristics apparently valid for autism. The Social Approach Test was developed to identify deficits in social interaction where a mouse subject is given a choice between a social and non-social environment (Moy et al. 2004; Nadler et al. 2004; Moy et al. 2007; Yang et al. 2007; McFarlane et al. 2008...... middle of article...... Brunssen and J. Waldrop, Review of the evidence for children autistic patients with selective serotonin reuptake inhibitors, Journal for Specialists in Pediatric Nursing 14(3) (2009), pp. doi:10.1111/j.1744-6155.2009.00196.xM Yang, ML Scattoni, V. Zhodzishsky, T. Chen, H. Caldwell, WS Young, HG McFarlane, JN Crawley, Social approach behaviors are similar across conventional and reversed light cycles and in cross-cohort replications, in BTBR T mutant mice + tf/J, C57BL/6J and Vasopressin Receptor 1B, Frontiers in. Behavioral Neuroscience 1 (2007. doi:10.3389/neuro.08.001.2007M Yang, V. Zhodzishsky and JN Crawley, BTBR T+tf/J mice are not modified by crossing with C57BL/. 6J Mothers, International Journal of Developmental Neuroscience 25(8) (2007), pp. doi:10.1016/j.ijdevneu.2007.09.008