PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -Melatonin is a hormone secreted by the enigmatic pineal gland in response to darkness, hence the name hormone of darkness. It has generated a great deal of interest as a therapeutic modality for various diseases particularly sleep disorders.

Detailed explanation-2: -Melatonin is the hormone best known to affect sleep, being low during the daytime but rising once darkness sets in, leading to sleep. Melatonin is secreted by the pineal gland, to which the SCN projects via multiple synapses to drive the Circadian rhythm of production of this hormone.