The human brain is the most complex organ in the body.
Having an understanding of how it works helps us to understand how drug addiction is a brain disease. Drugs affect the brain’s pathological and biological processes. Almost all drugs affect the chemical neurotransmitters, blocking natural receptors and preventing natural neuronal messages from getting through.
Just as different parts of the body are responsible for different actions, the same goes for the brain. Different parts of the brain are responsible for coordinating and performing different functions in the body: breathing, emotions, heart regulation, and much more. Drugs can alter any of these life-sustaining functions. Some of the areas in the brain that are most affected by drug abuse are:
The cerebral cortex – The cerebral cortex is divided into different areas that control specific functions. Some areas process the information from our senses, and the frontal cortex is the “thinking” part of our brain. This is the area that helps us solve problems, make decisions, plan, and in general, think.
The brain stem- The brain stem controls vital functions such as breathing, heart rate, and sleeping.
The limbic system – This is the brain’s reward circuit. It controls and regulates our ability to feel pleasure. This is the part of the brain that is activated by drugs. When drugs cause the brain to release extra dopamine, the “feel good” receptor, the brain wants more–it wants to keep feeling pleasure. The problem occurs when the brain begins to develop a tolerance to the drug, requiring more and more of it to have the same effect. Soon, the brain is unable to manufacture pleasure on its own. Eventually, the person needs the drug to feel normal.
Our brains are huge communication centers.
Neurons, or nerve cells, pass information back and forth not only throughout the brain, but also throughout the spinal cord and the nerves in the rest of the body. This is the networking of all we feel, think, and do.
When drugs are put into the system, they interfere with the tender communication system going on between all of the neurons and transmitters within the brain. They can activate neurons because similar chemical structures allow them to attach to and activate them. They may mimic the brain’s natural chemicals, but what they are really doing is killing them off, sending abnormal messages to the body, therefore leading not only to addiction, but also to death.
Drugs target the brain’s reward system, leading the brain, and therefore the body, to want and need more and more drugs, overdosing the body with dopamine. This is why once someone stops taking drugs, they may feel depressed; their body needs to readjust to dopamine working naturally once again. Chronic overexposure to drugs can change the chemical balance in the brain.
The National Institute on Drug Abuse. Effects of Drug Abuse on the Brain. Retrieved February, 2016.