Biological Explanation of Alcohol, Heroin and Nicotine addiction

Biological Explanations of Addiction

Genetic factors are believed to account for about half of the risk for alcohol addiction. Various genes may influence how alcohol tastes, the effects it has on body and the development of alcohol related diseases, which could potentially lead to chronic addiction.
Research suggests that alcohol addiction can often run in families, supporting the idea of a genetic predisposition. However, it’s also influenced by environmental factors, making it a complex, multifactorial issue.
Changes in brain chemistry and structure due to prolonged alcohol consumption may also contribute to addiction. Alcohol increases levels dopamine in the brain’s reward centre, which creates the pleasurable feelings. Over time, the brain adjusts to the excess dopamine and becomes less sensitive to it, leading to tolerance and the need to consume more alcohol to achieve the same effect.

Long-term use of heroin leads to changes in the physical structure and physiology of the brain, creating imbalances in neuronal and hormonal systems that are not easily reversed.
Heroin use increases levels of dopamine in the brain’s reward pathway. Over time, the brain becomes dependent on heroin to stimulate dopamine production, leading to tolerance and physiological addiction.
Genetically, an individual might be predisposed to be more or less vulnerable to heroin addiction. Some studies have identified specific genes that may influence this, such as those related to the body’s opioid receptors and the dopamine system.

Nicotine, one of the components of tobacco, is extremely addictive. It stimulates the release of dopamine in the pleasure circuits of the brain which is followed by a withdrawal period where the amount of dopamine decreases, leading to a feeling of well-being followed by depression, tension, and craving.
Nicotine’s effect on the brain occurs in seconds, and the effects start to wear off within a few minutes — which, in turn, leads the smoker to continue using nicotine to maintain the drug’s pleasurable effects and prevent withdrawal.
Just like the other two substances, genetic factors might influence nicotine addiction, but the specific genes involved are still a topic of research. Studies have suggested genes related to dopamine function in the brain might be important.