What Do Twins Teach Us About the Opioid Crisis?

This article was written in collaboration with Dr. Nathan Gillespie, an international researcher of addiction genetics at the Virginia Institute for Psychiatric and Behavioral Genetics.

Opioid overdose deaths have quadrupled since 1999; now 91 Americans die each day due to an opioid overdose according to the CDC. As many as 1 in 4 people who receive a long term opioid prescription not related to cancer struggle with addiction.

While opioids are the most visible example of prescription drug misuse, national data does not tell the full story of the opioid crisis and its impact on adolescents.

In contrast to the growing crisis of adult opioid use, over the past 5 years opioid misuse in high school seniors has dropped 45 percent, from 8.7 to 4.8 percent according to the Monitoring the Future survey administered by the National Institute on Drug Abuse. While the drop is a promising step in the right direction, there is more to the story of prescription drug misuse than just opioids.

Opioids are not the only prescription drugs used recreationally by adolescents. These drugs range from painkillers to stimulants prescribed for ADHD or depressants used to treat anxiety and panic disorders. Many of these drugs have little in common besides the fact that they come from a doctor, but they interestingly share many similarities when it comes to who uses them and who is at risk of developing problems.

Recreational use of prescription drugs is highly correlated with licit and illicit drug use including cannabis, nicotine, and cocaine, as well as various types of party drugs. And research also shows that the risk factors for use and misuse are shared across all prescription drugs regardless of the differences between the drugs.

As we unveil a clearer picture of addiction in adolescents, behavioral geneticists continue their studies using data from twins. Why twins, you ask?

By their nature, twins are perfect for exploring genetic and environmental risk. Identical twins share 100% of their genetic variation while fraternal twins share 50%, just like ordinary siblings. In twin studies, researchers send surveys to hundreds of twin pairs to learn more about their demographics, lived experiences and substance use. After analyzing the data, the different degrees of genetic relatedness allow researchers to estimate the contribution of genetic versus environmental influences.

In the case of non-medical use of prescription drugs, the shared genetic risks include personality traits like impulsivity, sensation-seeking, not coping well with stress.

So what can you do to mitigate risk if you are an impulsive or anxious person?

While there are risk factors for substance use, there are also protective factors too. One protective factor for adolescents is parental monitoring: how much your parents know about where you are, who you are with and what you are doing.

Surprisingly, the impact of parental monitoring doesn’t end when a teenager leaves their home. Spit for Science studies show that the impact of high parental monitoring follows an adolescent from home to college and throughout their lifespan.

In addition to parental monitoring, there are many other ways that environments mitigate genetic risk. For example, if you don’t have access to prescription opioids, then you are less likely to initiate use than someone who readily has access to them. So it is important to remember that just because a person is genetically at risk, that does not mean they are destined to develop a substance use disorder.

Using this knowledge Spit for Science researchers are focusing their future efforts on ways to improve prevention programs for adolescents so that they do not develop problems with prescription drugs in the first place.

Currently, researchers are analyzing the sex and ethnic differences across recreational prescription drug use in Spit for Science data to learn more about how universities can tailor prevention and intervention programming to the specific needs of students. Researchers also plan to link this research to retention and GPA data to create a full picture of where and how students need support and how that impacts their overall success at VCU.

While the opioid crisis is still one of the most pressing public health concerns facing our nation, each day scientists learn more about the risk and preventative factors that underlie substance use disorders and use this information to help those in recovery as well as those who are at risk of developing problems in the future.

If you want to be a part of discovering solutions to the Opioid Crisis through research, visit the Spit for Science website or view this interactive infographic on ways you can include our work in your college experience.