HTR2A and major depressive disorder: A study found that a candidate for Serotonin 2A receptor gene (5HT2A) receptor (HTR2A), which is located on chromosome 13q14-q21, was associated with mental (depression, schizophrenia) and behavioral (suicidal and aggressive behaviors) disorders and was associated with chronotype in a healthy population (Yeom et al., 2020).