Cocaine and Methamphetamine are two stimulant drugs that we know to be highly addictive. These drugs both have terrible physical, emotional and psychological effects on users, including stroke, heart damage, aggressive behavior and decreased cognitive function. Symptoms of these drugs may be commonly known; however, the general public does not understand the science behind drug addiction.
What is dopamine?
Dopamine is the neurotransmitter that is responsible for signaling the reward pathway in the brain. Dopamine release is triggered by cues that predict reward (smelling fried chicken), and causes anticipation of the reward (eating fried chicken). If the reward (the fried chicken) does not appear, then the dopamine cell stops firing, and the reward (the feeling of eating delicious food) isn’t experienced.
Dopamine pathway in the brain
Dopamine neurons are located in the ventral tegmental area (VTA) of the brain, and they release dopamine into the nucleus accumbens (NAc). This pathway plays a significant role in the processing of reward-related stimuli, especially those associated with drugs of abuse.
How dopamine works to produce a high
When the brain is exposed to a drug of abuse, there is a quick and intense surge of dopamine released from the VTA. This overabundance of dopamine travels to the NAc and binds to the D1 and D2 dopamine receptors, causing maximum reward.
How are drugs different than food or sex?
For natural reinforcers such as food or sex, the dopamine signals will drive the motivation to get the reward. When the reward appears, the dopamine cells will stop firing, and the anticipation of reward goes away. This works very differently however when dealing with drugs of abuse. Due to their pharmacological properties, the drugs continue increasing dopamine release during their consumption.
How does this affect drug usage?
Since drugs cause the continual release of dopamine, the desire to take the drugs upon exposure to cues is increased, as well as the motivation to continue consuming them during use.
How does repeated exposure affect the brain?
As these stimulants are taken more often, the “high” is reduced, but the motivation to continue to take the drug is undiminished. The quantity of D2 dopamine receptors in the NAc is reduced, and this change contributes to tolerance. High drug doses cause the dopamine pathways to become stronger and more developed, therefore increasing the brain’s reactivity to drugs and drug cues.
Long-lasting memory of the drug’s rewarding and conditioning effects will modify behaviors. The neurons will grow and create bigger synapses, resulting in stronger connections and cues/triggers for drug use. The number of dopamine receptors will be decreased, leading to impulsivity, which can predict increasing and compulsive administration of stimulants. This also results in a lack of self-control and the inability to feel satisfied.
The conflict between the “highs” and the lows
Addicts experience cognitive dissonance because they know the drugs are terrible for them, but they feel so good when they are high, which they don’t want to lose. It is very challenging to quit because the circuitry of their brain has changed and they cannot control their cravings or impulsive behaviors.
Society’s view on drug addicts
It seems as though society lacks sympathy for addicts, but to what extent is it their fault? They made the choice to use drugs in the first place, but it led to a downward spiral that they never expected and can’t escape. The brain can undergo extreme irreversible changes after just one exposure, and this is something that many may not realize until it is too late.
Options for addicts
Treatment plans can help addicts improve, and there are oral prescriptions that can be taken to reduce cravings, but extreme steps and lifestyle changes must be made if an addict is to truly recover and avoid relapse. The difficult part about preventing relapse is that it usually requires a complete lifestyle change. The cues that trigger drug cravings must be removed, and if these cues include certain friends or a home environment, the changes required would be pretty drastic.
In recognizing just how scary, complex, and difficult drug addiction can be, it is truly in one’s best interest to stay away from drugs and avoid the chance of becoming addicted.
For more information on the brain on drugs, please visit https://moodle.cord.edu/pluginfile.php/642483/mod_resource/content/0/the%20brain%20on%20drugs%202015.pdf
To learn more about the dopamine pathway in the brain, view this following video