- Environmental and environmental factors
The role of environmental factors in the development of nicotine (and other drug) addiction is also very important. Studies show that human addiction is the result of a dynamic interaction between their genes and the environment in which they live.
For example, a community that offers healthy activities, especially schools, has been shown to reduce vulnerability to tobacco (and other drug) dependence, and evidence suggests that access to physical activity can inhibit drug-seeking behaviour, an effect that is more marked in males than females. In addition, it is clear that drug exposure or stress in a person's social or cultural environment can alter both the expression and function of genes, which in some cases can persist throughout life. Research also shows that genes can influence how people respond to the environment, putting some people at greater risk of disease.
- Genetics and possibilities of pharmacogenomics
An international team of over 100 scientists used a large database to collect information on tobacco and alcohol-related behaviors. They measured data such as age at which they started smoking and age at which they quit, number of cigarettes per day and number of drinks per week. They then compared these results with life events (such as years of schooling), physical characteristics (such as heart rate and cholesterol levels) and past medical conditions (such as mental health disorders or type 2 diabetes). The researchers correlated these results with specific genes suspected to be involved in different types of drug use.
They found that there are over 400 locations in the genome and at least 566 variants between these locations that affect drug and alcohol use, bringing science closer to identifying clusters of genes that may be involved in addiction. The study even revealed new genes and functions that were not expected and that play a major role in the development of addiction. Three genetic locations (identified as CUL3, PDE4B, PTGER3) were associated with all measured smoking and alcohol consumption phenotypes.
Genes influence the number and type of receptors in the human brain, how fast the body metabolizes drugs and how it responds to different drugs. More knowledge about the genetic, epigenetic and neurobiological basis of addiction will allow science to advance in the study of addiction.
This knowledge will soon be applied to new treatments that target specific targets in the brain, or to treatment strategies known as pharmacogenomics. This new science promises to harness the power of genomic information to improve addiction treatment by tailoring treatment to a person's specific genetic makeup.