Effects of Addiction
What is it That Makes Drugs so Addicting?
Our brain is set up in a way that will make us repeat pleasurable activities. The reward center of the brain releases bursts of dopamine signals, in the result of healthy, pleasurable experiences. Dopamine helps with the formation of habits, it causes ‘neural connectivity’ making it easier to repeat activities without thinking about it. However, just as drugs are able to create surges of endorphins, they can also produce large surges of dopamine. When this happens it reinforces the connection between consumption of the drug, resulting pleasure, and all the external cues linked to the experience. This ‘teaches’ the brain to seek drugs over other healthier pleasure alternatives.
Parts of the Brain That Are Affected by Addiction
Basal Ganglia
This is the part of the brain that provides motivation, including the pleasurable effects of healthy activities (such as eating and socializing). This part of the brain is also involved in the formation of habits and routines. Overall this part of the brain is also known as the reward circuit. When drugs are introduced to this part of the brain. It can ‘over-activate’ the circuit causing it to produce a feeling of euphoria. However, when it is continuously exposed to drugs it causes the brain to adapt or get used to the presence of the drug, diminishing its sensitivity, making it hard to feel the pleasure from anything but the drug.
Prefrontal Cortex
​This part of the brain is responsible for our ability to think, plan, solve problems, make decisions, and exert self-control over impulses. When a person uses drugs it cause the brain to shift balance between the prefrontal cortex, extended amygdala, and basal ganglia, it causes them to compulsively seek more drugs due to their reduced impulse control. This is last part of the brain to mature, which makes teens more vulnerable to addiction.
Extended Amygdala
This part of the brain is involved in controlling feelings relating to stress (anxiety, irritability, and unease). This part of the brain is more effective after the effects of the drug have worn off, in other words, this is what causes withdrawal and makes people crave and seek the use of drugs again. This part of the brain become sensitive as a person increasingly continues to use drugs. After a while it will cause the person to seek drugs as a temporary relief from this discomfort rather than to reach euphoria.
Brain's Reward System
Euphoria and the cause of it are not fully understood. However, scientists believe that it caused by a surge of chemical signaling including the body’s natural endorphins and other neurotransmitters in the basal ganglia. This usually occurs naturally in a much smaller burst from the brain’s reward system, but when drugs the surges of these neurotransmitters to be much greater.
Why Do People Prefer Drugs Over Natural Rewards?
​When a person misuses drugs or alcohol, it causes the brain to produce fewer neurotransmitters and reduce the signal receiving receptors in their reward circuit. This causes the person to reduce their ability to experience pleasure from naturally rewarding activities. As the person builds their tolerance to the substance, they will have to increase their dosages to experience even a normal level of pleasure from the reward circuit. At the same time, the substance also affects chemical messengers and neurotransmitters.
Drugs affect chemicals that inhibit the transfer of electrical impulses between neurons. In neurons, messages travel from the cell body down the axon to the axon terminal in the form of electrical impulses. then, the message is sent to other neurons through neurotransmitters (through the synapse).
Normal Brain
Addicted Brain