Addictive Substances: Alcohol
Even though it is legal from a certain age (in most countries around the world either 16, 18 or 21), alcohol is a highly addictive substance. Alcohol abuse or addiction are major drug problems, with some people being more susceptible as others. Roughly 15 million people in the United States can be classified as ‘alcoholic’ and fetal alcohol syndrome affects about 1 to 3 of every thousand babies born in the States. This is a leading cause of preventable mental retardation. Chronic liver diseases, the main health problems connected to alcohol abuse, are responsible for more than 25.000 deaths each year. The annual cost of alcohol addiction and its direct consequences is an estimates $185 billion in the States alone.
Nature and Nurture
Both genetic and environmental factors contribute to the risk of becoming an alcoholic, but there is not a single factor that allows an accurate prediction of who will or will not become addicted to alcohol.
The Main Ingredient
The main active ingredient in alcoholic beverages is ethanol, which reduces anxiety, tension and naturally occurring inhibitions. In low doses, this substance acts as a stimulant, whereas in high doses its effects are similar to those elicited by a depressant. In both of these cases, ethanol is able to significantly alter the mood and the behavior of the person that ingested the substance, whether it be in low or high doses. Furthermore, it can also lead to loss of body heat and mild to severe dehydration.
How does alcohol do what it does?
Alcohol is absorbed relatively easy in the bloodstream and transported to the brain. Here, it affects several neurotransmitters, messenger molecules that carry signals from one neuron to the next. An example of one of the affected neurotransmitters is GABA (gamma-aminobutyric acid). When alcohol interacts with its receptor, anxiety can be calmed, muscle control impaired and reaction time delayed. At higher doses, alcohol also decreases the function of the NMDA (N-methyl-D-aspartic acid) receptors. These receptors recognize the neurotransmitter glutamate. The results of this interaction are, among others, the loss of clear thinking capacities and eventually this interaction could lead to a coma.
Several treatments are being developed by researchers. These treatments interfere with molecules, such as the opioid peptides, that trigger positive reinforcing effects of alcohol as a result of the activation of the brain reward system. One such drug, naltrexone, has been recently approved for the treatment of alcoholism.