There are many ways to think about what happens to brain addiction. I like to categorize it into four major categories listed below
- Motivation Circuitry
- Anti Reward pathway
- Interoception
- Amygdala/neurotransmitters
Other ways to think about what happens to the brain in addiction include the Stop-and-Go Model of addiction and the 3 stages of the cycle of addiction. I will be focusing on the 4 big categories mentioned above, however, I may delve into the other ways of thinking to further explain things if needed.
Motivation Circuitry
This is what most people think of when they learn about addiction. This is related to the “dopamine” of addiction. Only thinking about dopamine in addiction is too simplified. It is better to think about the motivation circuitry involving two big regions of the brain, the primitive dopamine region, and the more advanced prefrontal cortex. If the dopamine surge “wins” the prefrontal cortex then addiction happens; If the prefrontal cortex “wins” then addiction is less likely since the prefrontal cortex can tell the person not to listen to the dopamine surge
The videos show brain images explaining why and how the medical community knows about dopamine surges and the prefrontal cortex. Please watch the video for the explanation of the pictures below.
Anti Reward Pathway
2 Psychologists, Amos Tversky and Daniel Kahneman won the Nobel Prize in Economic Sciences for proving a fact about humans that could be used to make profits. This fact about people is that: people avoid risk to ensure gains, and people take risks to avoid losses.
When it comes to addiction, the portion of the brain that wants to ensure gains even if it doesn’t logically make sense (i.e. make sure you feel good) is likely the dopamine surge discussed in the motivational circuitry.
The portion of the brain that deals with people taking risks to avoid losses (i.e doing anything not to feel bad) appears to take place in a region of the brain called the habenula. A big part of addiction, especially in the later stages, is not for the person to feel euphoric/good, it’s actually for the person to stop feeling bad. In fact, in many addictions, people use the substance just to feel normal again. They don’t even feel the pleasurable effects. This is why the habenula is thought to play a major role in addiction. Doing things not to feel bad is known as the anti-reward pathway.
Interoception
Interoception (also considered to be a sixth sense to many people) is when the body takes all of the signals the body receives and puts them together to give them meaning. For instance, sensations translated to thirst, pain, itch, hunger, breathlessness, and body temperature are thought to be due to interoception. In addition it is thought that interoception plays a great deal in “cravings”
Interoception is thought to occur in the insula of the brain. A scientist showed that in heavy smokers if they had a stroke in this region of the brain, the cravings to smoke disappear.
This insula and interoception are also thought to be related to many eastern medicine practices such as mindfulness practices and yoga. Therefore, there may be a link here between Eastern and Western medicine. This is a current area of study addiction medicine researchers are focusing on.
Other: Amygdala and Hormones
The amygdala has an important role in regulating emotions and fear. It is implicated in anxiety, depression, PTSD, phobias, and more. Chronic drug and alcohol use makes the stress response and how the amygdala works out of balance. Hormones/Neurotransmitters in the brain including norepinephrine, corticoid release factor, glutamate, all get out of balance in a way that makes a person want to use.
This is why environmental factors associated with increased stress have been associated with drug use. Factors such as being poor, having no parental support, and being overworked all contribute to stress (i.e elevated cortisol- the stress hormone). This stress in turn leads to people using drugs to make things feeling less stressed again. Scientifically, it isn’t a surprise that when people are stressed it may lead to relapse.
Stress reduction helps people with addiction. This is a priority in many treatment centers, although the western medical system hasn’t been great in demonstrating this. In my experience, it seems like my patients think I am adding stress to their lives by telling them they have more things to do like going to intensive outpatient treatment. However, the long term goal is stress reduction. I will talk more about this in future sections.