As a college student I often hear stories from friends and classmates that involve lots and lots of alcohol. Not one to drink, I didn’t really know much about alcohol and its effects, other than what kids are told in grade school. After doing some searching I found out that, not only was there a lot of information known, but that there was still a lot of research being done on the topic.
Some interesting statistics that I found include:
– Alcoholism is one of, if not the, most prominent neuro psychiatric disorders in society today.
– In 2010 the number of alcohol-induced deaths, excluding accidents and homicides, was 25,692.
– Around 35% of abuse victims report that offenders are under the influence of alcohol.
– Alcohol use is also associated with 2 out of 3 incidents of intimate partner violence.
– Alcohol is often a major factor in cases of child abuse and neglect and 10% of children in the US live with a parent that abuses alcohol
Statistics like these make me wonder why people drink alcohol. What is it about alcohol that leads us to consume it? Why do some people become dependent on it? It turns out that alcohol, like other drugs that humans tend to use and abuse, actually causes changes to our brains when it is used frequently enough and in large quantities.
The neurological pathway that leads to alcohol addiction is called the Reward or Pleasure pathway. This pathway involves multiple regions of the brain including the ventral tegmental area (VTA), the nucleus accumbens, and parts of the prefrontal cortex. Unlike other drugs alcohol does not directly affect the dopamine pathway, which is an integral part of the reward pathway. Instead it acts on GABAA receptors located on interneurons in the VTA. Ethanol binds to the GABAA receptors and cause GABAA gated chloride channels to open, and stay open longer than normal. This leads to the neurons becoming excitatory, and their interaction with the reward pathway causes an increase in dopaminergic activity in the VTA. The dopamine from the VTA interacts with the nucleus accumbens, activating the reward system there as well.
Over time the human brain can become used to this overabundance of dopamine and become dependent on alcohol activating the reward pathway. This leads to dependency on alcohol meaning that the person is now addicted to it. Because the brain has been changed by alcohol if its use is discontinued there can be some very nasty side effects. These side effects are called withdrawal symptoms and they can start as soon as two hours after an addicts last drink. They can be extremely severe. So severe in fact that, if not treated, they can lead to death.
There are two categories of withdrawal symptoms, psychological and physiological. Anxiety and confusion are two of the more mild psychological side effects while hallucinations fall on the more extreme end of the spectrum. Physiological symptoms include shaking, sweating, nausea, and vomiting. They can also include more serious symptoms like high fever, irregular heartbeat, and even seizures, all of which require immediate medical attention. The avoidance of these withdrawal symptoms are a reason that, along with the modification of the brain, keep people dependent on alcohol.
Over all I learned a lot about alcohol use and abuse. Some of what I learned was quite scary and all of it definitely makes me think twice about heading out to have a drink with friends.
More information can be found:
Boileau I., Assaad J.M., Pihl R.O., Benkelfat C., Leyton M., Diksic M., Tremblay R.E., Dagher A. Alcohol promotes dopamine release in the human nucleus accumbens. Synapse. 49(2003):226-31
Pestell, Katharine. “Alcohol Addiction.” Trends in Pharmacological Sciences 22.9 (2001): 448. Print.
Lishman, W. A. “Alcohol and the Brain.” The British Journal of Psychiatry 156.5 (1990): 635-44. Print.
Vengeliene, V., A. Bilbao, A. Molander, and R. Spanagel. “Neuropharmacology of Alcohol Addiction.” British Journal of Pharmacology 154.2 (2008): 299-315. Print.