How Much is too Much?

I work in a managed care setting as a clinical lead, presenter, and trainer for the social work and registered nursing staff. Many questions have generated from the staff regarding what neurochemical changes lead to addiction. For example, many social workers and nurses have verbalized wanting more education about the specific neurotransmitter messengers and cortical structures that are responsible for learning and enjoying drugs. The main question asked by many associates is “Are there respective pathways involved?

As we know, the frontal cortex is the “thinking” part of the brain; and, the posterior part of the frontal cortex called the pre-motor cortex that actually works hand in hand with the pyramidal motor tracts. I understand completely how long term use of alcohol leads to Wernicke’s Encephalopathy and can progress into Korsakoff’s syndrome-a persisting and degenerative amnestic disorder that has less than a 20% prognosis rate. I also have seen the direct effects working with persons in the tertiary stages of alcoholism.

When I wear my training hat, I am educating staff on the chemistry behind the addiction; and, the medical sequelae often developed as a result of the addiction, e.g., pancreatitis, hepatomegaly, alcohol induced cirrhosis, and portal gastropathy that often results from chronic use of alcohol, which may indicate the patient is in the tertiary stages of alcoholism.


Why is this all sounding dismal? Well, it does have something to do with our brain and physiology. When we drink alcohol, if we drink daily, that leads to brain and blood based tolerance changes. When our blood levels drop for alcohol, or any drug that we have developed a tolerance, it leads to cravings, possibly even withdrawal effects that drive one to obtain the drug.

Let’s first take the domains of functioning. To begin, the physical, i.e. sick, nausea, vomiting, diarrhea, these are signs of either a hangover the next morning, or, if the person hasn’t had a drink in a day or two, that withdrawal is taking effect. Now, the emotional, there are patients that when they do not drink, they are depressed, angry, and even more anxious. Also, that sense of control that is lost when using the drug. Remember, tolerance changes take effect. What does that mean for the person addicted? Perhaps, the desire to experience and then re-experience pleasure. There is scientific reasoning behind the pleasure-pathways principle on brain and neurological functioning.

Dopamine, also known as the pleasure pathway neurotransmitter, is a catecholamine (a hormone produced by the adrenal glands in response to stress) that has important roles in cognition, voluntary movement, motivation and reward. Inaba refers to Dopamine as the “reward chemical” that is most critical in drug use and abuse. This reward model is an operant conditioning model that occurs when dopamine neurons occur when an unexpected reward occurs. Dopamine neurons are reduced when the expected outcome doesn’t occur. It is theorized that addiction occurs when the behaviors that are rewarded by the increase of dopamine are repeated. Dopamine cannot cross the brain-blood barrier and so when given as a drug doesn’t affect the central nervous system. Maybe, this has made a difference in some person’s life and understanding addiction as something that has a physiological basis, emotional foundation, and is treatable.

Dr. Stephanie Sencil, PsyD, PhD, LCSW, DCSW

Reference:

Inaba, D.S., & Cohen, W. E. (2007). Uppers, downers, all arounders (6th ed). Medford, OR: CNS Productions Inc.