SLC6A4 and Abnormal emotional state: Although underlying molecular mechanisms are poorly understood, dysfunctions in 5-HT reuptake (5-HT transporter, 5-HTT), catabolism (MAO-A), and postsynaptic receptors (5-HT2A and 5-HT2C) are thought to disrupt PFC top-down control over the amygdala, resulting in emotional dysregulation (1,77–83).