Limited information from well-conceived and well-executed studies means that researchers don’t really know how much specific genetic backgrounds affect susceptibility to substance problems or the course of substance treatment, according to new findings from an American university.
Broadly speaking, researchers and doctors know that your genetic makeup significantly influences your chances of developing diagnosable problems with drugs or alcohol. In a study review published in July 2015 in the journal Drug and Alcohol Dependence, researchers from Columbia University’s New York State Psychiatric Institute and College of Physicians and Surgeons examined the current state of knowledge regarding the connection between particular genetically determined responses to various substances and the chances of developing a diagnosable case of substance abuse or substance addiction. These researchers also looked at the connection between genetically determined substance responses and the odds of receiving successful substance treatment.
Genetics and Substance Addiction
Substance addiction occurs when a person who repeatedly consumes excessive amounts of alcohol, a drug or a medication undergoes persistent chemical change in the pleasure center, a brain area that helps determine the amount of reward associated with various types of behavior. The chemical change in question produces a physical dependence on continuing substance use and also motivates involvement in a range of damaging behaviors consciously or unconsciously designed to prioritize substance intake and secure substance access.
The National Institute on Drug Abuse reports that genetic factors help determine roughly 40 percent to 60 percent of the odds that any given person will become addicted to drugs or alcohol. However, the relationship between a genetic predisposition toward addiction and the real-world development of addiction symptoms is quite complex. First, it’s important to note that multiple genes in human DNA help determine an individual’s addiction susceptibility. This means that a broad range of genetic variations work together to increase or decrease your overall odds of developing addiction-related problems. Behavior and environment also play a critical role in triggering problematic substance use. For example, even if you have a noted genetic susceptibility to the effects of drugs or alcohol, you won’t develop an addiction if you avoid substance intake. In addition, various factors in your social environment can boost or decrease your likelihood of embarking on a pattern of drug or alcohol use.
Some forms of substance treatment are based on psychotherapeutic approaches that don’t include the use of medication. However, drug and alcohol treatment often involves the use of a medication option. Examples of addiction medications include the alcoholism treatments disulfiram and acamprosate, the opioid addiction treatment buprenorphine and the nicotine addiction treatments varenicline and buproprion. Doctors and researchers are well aware that not all people who receive medication-based addiction treatment experience similar short- or long-term treatment outcomes.
How Much Do Genetic Details Matter?
In the study review published in Drug and Alcohol Dependence, the Columbia University researchers used a large-scale analysis of previously conducted studies to clarify the connection between various genetic variations, the odds of developing specific types of substance abuse/addiction and the odds of successfully dealing with abuse/addiction issues while enrolled in substance treatment. The researchers sought to identify particular combinations of genes and life experiences that make a person more likely to consume drugs or alcohol in excessive amounts, more susceptible to the cues and urges that support uncontrolled substance intake and/or less likely to benefit from the medications used in substance treatment.
Originally, the researchers had hoped to find enough relevant studies to create a broad-based consensus on the relationship between genetic factors, environmental factors and substance-related risk. However, after completing their review, they concluded that there simply are not enough high-quality studies to support such an approach. Instead, the researchers focused their efforts on the relatively small number of studies that rigorously addressed the issues under consideration. Ultimately, they concluded that specific combinations of genes and life experiences almost certainly influence basic risks for substance problems and likely outcomes of medication-based addiction treatment. However, they also concluded that, even when evidence backs a connection between certain genetic/environmental combinations and substance-related risk, there is not enough supporting research to verify current findings.
Overall, the study’s authors characterize the results of their review as “conflicting.” Still, they believe that better-designed future research efforts will likely make it much easier to identify specific combinations of genetic and environmental factors that make substance addiction more likely and make positive substance treatment outcomes less likely.