The serotonin 1A receptor (5HT1A) has been implicated in the regulation of neuroendocrine responses to stress in juvenile and adult animals [8–12, 53], and the C(-1019)G polymorphism in the promoter region of the human htr1a gene is associated with depression and antidepressant treatment resistance [13, 14]. This evidence concerns the gene HTR1A and depressive symptom measurement.