When the brain is under attack

By nature, rewards usually come only with time and effort. And like I had mentioned before, addictive drugs and behaviors provide a shortcut, flooding the brain with dopamine and other neurotransmitters. Our brains do not have an easy way to withstand the onslaught. Addictive drugs, for example, can release two to 10 times the amount of dopamine that natural rewards do, and they do it more quickly and more reliably. In a person who becomes addicted, brain receptors become overwhelmed. The brain then responds by producing less dopamine or eliminating dopamine receptors an adaptation similar to turning the volume down on a loudspeaker when noise becomes too loud. As a result of these adaptations, dopamine has less impact on the brain’s reward center. People who develop an addiction typically find that, in time, the desired substance no longer gives them as much pleasure. And because of that, the development of drug addiction tolerance begins  hence they have to take more of it to obtain the same dopamine “high” because their brains have adapted and that is what is known as tolerance.