Answer: The Brain stops to produce Endorphins.
Explanation: Endorphins are special chemical substances produced by the Human body,it is produced in different organs especially areas of pain and stress and also in the Brain, Endorphins reacts with optiate receivers in order to help reduce the impact of pains and stress on the Human body,endorphins also helps to transmit electric signals through the nerves. When the Brain is repeatedly flooded with artificial opiates(drugs that tries to act like natural opiums) it causes the Brain to stop the production of Endorphins.