In the addiction treatment industry, the efficacy of the treatments that we can offer those suffering from addiction are largely based on our understanding of this deadly disease. We know a lot about addiction today, but it’s nowhere near enough. With the combination of scientific research and a multidisciplinary approach, we continue to develop better ways of treating addiction in the hope of curbing the epidemic-level rates of substance abuse we see today. But it’s not just about treatment.
By gaining a better understanding of how the addicted brain works, those of us who have experienced addiction personally – either due to having previously been an addict or having an addicted loved one – are able to draw parallels between the behaviors and circumstances prior to addiction and the disease itself. With this knowledge, we can better understand how today’s addicts came to be in their current situations, which allows us to empathize with and help them more effectively. It’s not just about fighting addiction on a national or global scale, but also at the most basic, personal levels, too.
When it comes to studies on addiction, we’ve always got an ear to the ground. After all, today’s scientific breakthroughs directly contribute to increasing success in the addiction treatment industry. This week’s breakthroughs are particularly illuminating with regard to the neurology of addiction, telling us a lot about how people become addicted and why they continue their substance abuse when there are so many repercussions.
Painkillers Actually Worsen Physical Pain
First, let’s take a look at opioid addiction, which has become the most concerning as indicated by the CDC’s use of the term “epidemic” to describe it. According to the National Institute on Drug Abuse, about 20,000 people died from a prescription opioid overdose in the U.S. just last year. As you’re aware, an opioid is a substance that is opium-like in its effects but may or may not be opium-like in terms of its chemical composition. The majority of opioids are the painkillers that are prescribed to patients experiencing chronic pain. In the mid- to late-1990s and the majority of the 2000s, people experiencing health problems that caused them pain found that many physicians were quite liberal with opioid prescriptions, initiating a surge of painkiller abuse and addiction that we’re still fighting today. However, a new study suggests that painkillers might ultimately make chronic pain worse while offering the illusion of temporarily pain relief.
Conducted by a research team out of the University of Colorado Boulder, the study was conducted on rats to determine some of the specific effects of opioid use and abuse as well as their implications. Assistant research professor Peter Grace and distinguished professor Linda Watkins, the two co-leads of the experiment, observed that after receiving just a few days of morphine treatment, rats showed a substantial increase in the amount of pain they experienced via pain signals sent from the rats’ central nervous systems. In particular, the pain signals were being sent by immune cells located in the spinal cord. These observations led to intense speculation that the same thing is happening to humans who are taking opioid medications to treat their pain but who aren’t typically experiencing an improvement in their symptoms. Could it be that opioid painkillers – long thought to be one of few treatment options for chronic pain – exacerbate the problem?
According to Grace, who, in addition to Watkins, is a member of the University of Colorado Boulder’s Department of Psychology and Neuroscience, this is the first study to show definitive proof that even a brief period of exposure to opioid substances can have major, long-term effects on pain. “I look at it like turning up a dimmer switch on the spinal cord,” Grace said, referring to how the opioid medications increased pain signal transmission from the spine as well as pain sensitivity.
With just five days of opioid treatment, the response was unexpectedly extreme. The immune cells in the spinal cord, also called glial cells, exhibited a surge of activity in a sort of cascading effect, sending out stronger and more frequent pain signals while also becoming noticeably inflamed. When a peripheral injury is involved, the process escalates further, producing signals from a certain protein that increases the functioning of pain-responsive nerve cells in the brain and throughout the central nervous system. The result is not only an increase in the severity of pain but also a significantly longer duration of pain with several more months of pain observed in the rats than they would otherwise have experienced, per the control group.
The study has been extremely enlightening for several reasons, but arguably the most significant implication pertains to healthcare. Historically, the people who were at the highest risk for becoming addicted were those who regularly used addictive substances over an extended period of time (i.e., as medicinal treatment for a health condition) and those who abuse such substances for recreational purposes; however, the increase in pain response and longevity of pain due to the use of any opioids at all, even small amounts for extremely brief periods, could make someone more likely to continue taking opioid painkillers. If the findings of this study are confirmed by additional studies in the future, healthcare providers will want to reconsider prescribing opioid drugs unless it’s in the most dire of circumstances because these drugs would clearly have an even higher potential for addiction than we’d ever imagined.
How the Brain Turns Behaviors Into Habits: The Center of Addiction
Some have said that we human beings are creatures of habit, which is a quirky way of saying that we’re a hominin species that enjoys routine. For most of us, day-to-day life consists of a number of routines that we use to manage time, stay productive, maintain our hygiene, meet our various responsibilities and obligations, and otherwise care for ourselves and any offspring we might have. When we choose to behave in a way that is beneficial, we will likely try to incorporate that behavior into one of our daily routines. And that’s how we go about our lives: Maintaining our routines while sifting through various behaviors that result from our choices, rejecting chaos while assimilating behaviors that help us to thrive.
You’ve probably noticed that when a behavior becomes a habit, it’s not easy to break. It requires conscious effort that we must sustain over a period of time so that we can essentially “unlearn” the habit. This is because the neurological processes that turn behaviors into habits are complex, especially when compounded by other factors as is the case with addiction.
A study by researchers at the University of California San Diego took a closer look at how the brain distinguishes between habits and the behaviors we exhibit by choice, which is goal-oriented or goal-directed behaviors. The particular goal of the study was to figure out how the brain governs our behaviors and what neurological differences there are, if any, between habitual impulses and goal-oriented behaviors.
Using a mouse model, Christina Gremel – assistant professor of psychology at the University of Colorado Boulder and lead researcher of the study – found that the neural circuits for habitual and goal-directed behaviors are in constant conflict. Additionally, Gremel observed that there are certain neurochemicals, called endocannabinoids that allows habitual behavior to dominate by effectively blocking the goal-directed circuit.
Endocannabinoids are naturally produced in humans as well as all other living creatures. They’re found in the brain, the central nervous system, and throughout the body, and they’re implicated in a number of very important physiological functions such as hunger, mood, pain sensation, and memory. As suggested by their name, they also act as a mediator for the effects of cannabis. In previous experiments, Gremel and her researchers used chemicals to alter the functioning of the orbitofrontal cortex – OFC – where the habitual and goal-directed circuits operate; increasing the activity of the OFC increased goal-directed action while decreasing activity in the OFC resulted in increased habitual behaviors. In the present study, Gremel observed that the endocannabinoids were quieting the OFC, disrupting goal-directed behavior while increasing habitual behavior.
To confirm this, the researchers inhibited a particular endocannabinoid receptor in the brains of a test group of mice. Both the test group and a control group were encouraged to press a lever using positive reinforcement, which means that they were offered a reward when they pressed the lever. The control group eventually continued to press the lever without requiring a reward whereas the test group was unable to develop habitual behaviors, instead being driven by certain goals.
A healthy brain can shift back and forth from goal-directed and habitual behaviors; whenever possible, a person defaults to habitual behaviors so that the brain can focus on other tasks but while retaining the potential to switch to goal-directed behaviors whenever necessary. This study shows a particular area of the brain that could potentially be influenced in such a way as to prevent a person from being especially reliant on habitual behaviors and, instead, help him or her to more easily overcome habitual behaviors such as addiction by preventing endocannabinoids from bonding with endocannabinoid receptors. At this stage this is theoretical but it leaves the door open for new treatments in the future.