Is Drug Addiction Hereditary?
Why do some people become addicted to drugs while others do not? Why does one sibling become addicted while his or her full sibling does not? Is it possible that hereditary factors are involved?
Yes. A tendency for addiction can definitely be passed from parent to child. In fact, up to fifty percent of the risk for drug addiction can be present in one’s genes.
However, overall, true substance addiction occurs in the general population at a very low rate: about ten percent.
These statistics demonstrate that hereditary factors play a significant, but certainly not singular, role in the development of a drug addiction. Therefore, a person who has inherited even a fifty percent predisposition for addiction isn’t necessarily doomed by their genes. There are other powerful factors at play, such as environment.
There are many children of dual-parent smokers who have never smoked. The same can be said for many children of alcoholic parents. Even though these children were exposed to these substances during their formative years, they themselves never became addicted. This tends to demonstrate that hereditary factors of addiction must be limited in some way.
It’s also true that many addicts are the children of parents who were not addicted to substances of any kind.
How Does Addiction Occur?
When a person uses an addictive substance regularly, changes occur in the brain. For example, regular use of opioids causes chemical brain changes that leave the brain unable to function normally without the opioid. Production of natural body opiates, known as endorphins, plummets. The brain grows extra opioid receptor sites. These are not normal.
The liver, responsible for detoxification of substances ingested, begins to recognize the abused drug. It starts to produce enzymes that break down the drug faster and faster. Less drug reaches the brain. Largely because of this, tolerance, or the need for more and more of the drug to produce the same effect, grows.
The person is driven by the need to get more of the drug, overwhelming drug cravings and the fear of withdrawal. This reinforces further drug use, creating an endless vicious circle. All drugs of abuse cause the brain to release dopamine, a brain chemical that causes feelings of pleasure. This also reinforces the need to use the drug again and again.
Certain sedative-hypnotics, such as barbiturates, alcohol and benzodiazepines, cause such profound brain changes that unsupervised detox can be life-threatening.
Unmedicated, non-medical detox from opioids, while generally not life-threatening, is highly unpleasant. Symptoms include stomach pain, vomiting, drug cravings, diarrhea, feeling hot and then cold, sweating, depression, extreme weakness, muscle and bone pain, headache and the inability to eat. Sometimes even sips of water won’t stay down. Duration of symptoms depends on the opioid, length of time used, dosage and individual factors, but they can persist for anywhere from a week to a month, and even longer.
Addiction and Genetic Testing
There are genetic tests available today that are supposed to be able to predict one’s predisposition for addiction. For example, some physicians are using the PROOVE test as a tool to predict a patient’s addiction risk for opioids. The idea is to try to weed out those patients, especially chronic pain ones, who have a high risk for addiction. The test combines a short questionnaire with an analysis of the patient’s DNA. This test focuses on genes relating to the brain’s limbic system, which has to do with mood and emotion. The brain’s reward systems and pleasure pathways are also located here.
No one knows how accurate these genetic tests really are, especially when performed on a single individual. This is because addiction is only partly determined by genes. It’s unfair, not to mention possibly wrong, to label someone a potential addict based on a genetic test alone.
Addiction and Environment
Environment has a powerful influence on addiction. Dopamine is the brain’s feel-good chemical. It causes feelings of pleasure and reward. It can be triggered by many non-drug things, such as exercise, work, pets, hobbies, fun activities and even just the beauty of a sunset or other natural setting. Release of dopamine can also be caused by certain drugs of abuse, especially stimulants.
When people live in depressing, poverty-ridden, negative environments, where there is little emotional support, potential for drug abuse rises. It’s possible that people seek feelings of pleasure from drug-induced dopamine release, since natural sources are scarce.
It’s important to understand that the hereditary factors involved in addiction, while significant, do not determine addiction potential on their own. On the other hand, if one has a lot of addiction in one’s family, it would be safe to assume that there may be a higher risk for that individual.
No one really knows what lurks in their genes. Protect your health and your future. It’s best to avoid addictive substances whenever possible.