Serotonin receptors 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT2C are involved in the regulation of anxiety-related behaviors [6,7] and it has been shown that the activation of 5-HT1A and 5-HT2A may exert anxiolytic effects, whereas their inactivation increases anxiety-like symptoms [8]. This evidence concerns the gene HTR1B and Anxiety.