Genes and Opioid Addiction: A Potential Early Warning System
By Christopher Johnston, MD ABPM-ADM, Chief Medical Officer, Pinnacle Treatment Centers
One challenge physicians who prescribe opioid medication for pain management face is that it’s hard to predict who will develop an opioid use disorder and who will not. This is of primary concern today because the opioid epidemic persists across the country, though much attention is focused on the coronavirus pandemic. However, despite the primacy of the pandemic, the legions of physicians, nurses, therapists, counselors, medical assistants, support techs, and other healthcare workers in our country help everyone who needs help, when they need help, with whatever they need help with, whether it’s COVID or something else.
The presence of one public health emergency doesn’t make another go away: that’s why everyone working in healthcare right now is doing the equivalent of walking and chewing gum — times about a thousand. They’re walking a tight rope, juggling chainsaws, while breathing fire, while balancing a teacup on their head, all while singing “The sun’ll come out…tomorrow!” because they literally have no choice but to do their jobs — a.k.a. helping everyone who needs help when they need it — with a smile on their faces and hope in their hearts.
And just to be clear, they’re not doing it for themselves.
They’re doing it for you.
That goes for the research scientists, too: right now a team of geneticists at the University of Cincinnati is conducting a study to identify specific genetic markers which, if present, may predispose an individual to opioid addiction, known as opioid use disorder (OUD).
Genes and Substance Use Disorder: What We Know
I’ve had my eye on research around the genetics of addiction for years. It’s a promising field of study that may lead to big changes in the future — but we’re not there yet. What we do know is informative and helpful, but rather complex.
I know, that’s what doctors always say when they’re about to do one of two things: oversimplify a tricky topic, or offer you a ton of information that’s almost impossible to understand without a couple science degrees and a research assistant to chase down fact claims.
I won’t do either.
Instead, I’ll tell you straight-ahead what we know, as confirmed by a Genome-Wide Association Study (GWAS) conducted in Sweden in 2014 that included the health and genetic records of more than a million people:
1. There’s a hereditary component to alcohol and substance use disorders (AUD/SUD).
a. In males, the hereditability of disordered substance use was 55%, and in females, the hereditability of disordered substance use was 73%.
2. There’s also an environmental component to alcohol and substance use disorders.
a. Peer influence, availability of drugs, socioeconomic/neighborhood factors, and family influence contribute to AUD and SUD.
3. The combination of heightened genetic risk and heightened environmental risk does not mean an individual will definitely develop AUD or SUD, but it does raise overall risk of developing AUD or SUD.
That’s where we are.
The confirmation of the hereditability of AUD/SUD shows there’s a genetic component to addiction — but it’s not the whole story. The presence or absence of certain environmental factors shows there’s a life experience component to addiction — but it’s not the whole story.
Individual experiences interact with genetic makeup and, in some cases, result in AUD or SUD: that’s the whole story as we know it.
What About Opioid Use Disorder?
The landmark study out of Sweden looked at AUD/SUD in general. It’s an important study and contributes a great deal of knowledge to my field of addiction treatment. To learn more, read this article by my colleague Dr. Lori Ryland. She goes into depth about the complex interplay of genes, environment, and addiction.
This new research effort, though, does something different. Whereas the Swedish study took a broad look at AUD and SUD, this new study at the University of Cincinnati (UC) will focus specifically on genetic markers present in people who develop opioid use disorder (OUD). To understand why the UC research team thinks this research is necessary, let’s restate the first sentence of this article: doctors who prescribe opioid pain relievers for patients in acute and chronic pain cannot accurately predict who will develop OUD and who won’t.
Dr. Caroline Freiermuth, the researcher leading the project, describes the effort in a video produced and published online by Ohio Attorney General Dave Yost:
“We don’t know who will be harmed by opioids. There’s no linear model that says ‘these are the people who will develop opioid use disorder.’ We know from looking at familial studies, genetics plays a role, as well as your environment, for alcohol and substance use disorder. We’re trying to figure out the genetic piece, when it comes to opioid use disorder.”
In collaboration with Ohio State University, Dr. Freiermuth plans to recruit more than 1,500 patients with OUD in the coming months. Researchers will take saliva samples via cheek swab, scan for genetic markers related to OUD, and compare those genetic scans to people without OUD. In that way, they hope to identify the genetic markers unique to people who develop OUD.
I think this research team is heading in the right direction — because I like their endgame.
How This Research Will Help: An OUD Prescreening Tool
That endgame, according to Dr. Freiermuth, is to create an assessment tool that identifies people at high risk of developing OUD. They’ll combine information from questionnaires about past medical and psychiatric history, family history, and life experiences to create a screening instrument that will help doctors decide which patients should receive an opioid prescription and which patients — if they do need opioid medication for pain — should proceed with caution with regards to opioids.
For some patients, this may mean no opioid prescription at all — if the risks outweigh the rewards. For others, this may mean a short-duration prescription to manage acute pain after surgery or injury — but it would come with restrictions, based on information from the risk assessment tool. For some, the tool may reveal no increased risk of OUD at all: these patients would receive prescriptions for their pain as usual.
But I need to back up here. There is actually no more as usual where opioids are concerned. Just as the coronavirus pandemic will create a new normal around public behavior vis a vis public health, the opioid epidemic has already created a new normal around opioid prescribing vis a vis pain management. Rules and restrictions on amount, dosage, and duration of opioid prescriptions now exist where they didn’t before — and that’s a good thing.
Our Path Forward
This research moves us in a positive direction, but I have to remind everyone that there’s no magic wand we can wave that will suddenly solve addiction overnight. Don’t misunderstand me, though. If we discover a magic wand that cures addiction, I’ll get my hands on it and wave it until my arms drop off. However, we need to be realistic, and view new scientific developments in context.
We understand addiction as a complex medical condition that develops in response to a variety of factors unique to the individual.
Therefore, we’ll integrate any new tool we develop into that framework of knowledge.
What this new research can offer — if in fact scientists identify genes that predispose an individual to OUD — is a way to quantify the risk of OUD for patients so that we may create a targeted set of prescribing guidelines based on evidence and data specific to opioids, rather than generalized from data about alcohol and other substances of misuse.
With an OUD risk assessment tool that has a verifiable genetic component, doctors can work with patients to determine the best way to manage pain. Providers can work with high-risk patients to develop an alternative pain management strategy, medium-risk patients to ensure they understand the dangers of opioids, and low-risk patients to ensure they use opioids exactly as directed, and only in the amount they need.
An evidence-based approach like that has the potential to change the way we care for patients, and ultimately, mitigate the negative impact of opioid addiction on individuals, families, communities, and our nation as a whole.
