Addiction Changes the Brain's Communication Pathways
A. Tom Horvath, Ph.D., ABPP, Kaushik Misra, Ph.D., Amy K. Epner, Ph.D., and Galen Morgan Cooper, Ph.D. , edited by C. E. Zupanick, Psy.D.
In the previous section, we described the brain's electro-chemical communication system. This communication system sends information through a vast network of interconnecting neurons. Overtime, the brain develops a preferred or standard pathway to send signals between neurons (neural pathways). Until recently, we thought the brain's neural pathways had completely formed by the time we reached adulthood. However, because of new scientific developments we now know the brain is much more dynamic than we thought. The human brain continues to create new neurons and form neural pathways throughout our entire lifespan. Thus, neurons are dynamic cells that are constantly adapting to changing circumstances. If something damages a person's brain (such as a stroke or injury), the neurons can make new communication route around the damaged area. This ability is known as neuronal plasticity.
Scientists found that neuroplasticity regulates learning processes and helps us to adapt to our surroundings. As early as 1949, the neuroscientist Donald Hebb claimed that neurons that frequently fire together form stronger linkages. In other words, "neurons that fire together, wire together." This is one of the earliest descriptions of what we now call neuroplasticity.
To better understand neuroplasticity, an analogy may be helpful. Our brains' form neural pathways in a way that is similar to the formation of a well-traveled hiking trail. The more we travel a path, the faster, easier, and more familiar that path becomes. As we travel it more and more, it becomes wider, smoother, and easier to travel. It becomes a preferred route. The same is true of neural pathways. Overtime, the brain forms familiar neural pathways these become habitual routes. If a familiar route is blocked, the brain eventually forges a new route. Let's continue with our analogy. Suppose you walk through the woods each day to visit a friend. You use the same trail each time. One day, as you travel along your familiar path, you discover a huge tree has fallen over. It's blocking your passage. You will need to forge a new path to go around the tree. At first, this new path will be narrow, difficult, and slow. It might even be uncomfortable. Overtime, it will become a well-worn, comfortable path. It will be just as easy as the original path.
New neural pathways are formed as addiction develops. This is because addiction chemically altered the brain's communication system. When you take that drug away, the brain must again form new neural pathways. Just as when we had to forge a new trail in the woods, this is initially uncomfortable. Neuroplasticity explains why the initial period of recovery is difficult and uncomfortable. But we know from our hiking trail example, this difficulty is only temporary. This information is very helpful to know when attempting recovery. We can be successful if we preserve through this brief, uncomfortable period. Remember, it was difficult and uncomfortable to forge a new pathway around a fallen tree. The same is true for the initial period of recovery. It can be difficult and uncomfortable while these new neural pathways are forming. As long as the recovering person does not give up during this initial period of discomfort, new neural pathways will form that support recovery. These new pathways will become more established and better developed over time. As they do, recovery becomes easier and more comfortable.
We have emphasized the adaptive, dynamic qualities of our brains ensure our survival. Unfortunately, the brain's ability to be so adaptive is also at the root of addiction. The brain adapts to the strong effects of addictive drugs and activities. When it does, changes occur in the brain regions associated with reward, memory and emotion, decision-making, and stress regulation. These changes to our brain make the repeated use of addictive substances or activities very compelling. The good news is that our brains' neuroplasticity allows us to correct these changes! Therefore, although addiction leads to structural changes in the brain, we are capable of learning new coping skills. The brain's plasticity allows these new coping skills to be imprinted. We discuss these structural changes in the next section.