In a span of just fifteen years between the late 90’s and early 2000’s, drug overdose fatality rates in the United States increased threefold (Huang, Keyes, & Li, 2018). In 2017, a record number of deaths were reported by the Center for Disease Control. Increasing by 10% since the year prior, 72,000 Americans succumbed to drugs in 2017 alone, according to Sanger-Katz (2018). Drug abuse has become an increasing epidemic in the US. More people are addicted to drugs than ever before, and drugs are becoming progressively easy to stumble upon. In the past, drug addiction has been a taboo subject. It was seen as a weakness, a severe shortcoming, and was most importantly seen as a choice. The idea was that those that were unable to wean themselves off of drugs were not trying hard enough, or that they did not want it badly enough. In recent years, we have come to understand just how important of a role biology has in addiction. For quite some time, drug addiction was not seen as a disease deeply rooted in its underlying biology. It was assumed that it could be turned on and off like a switch. Now that the expansive biological component of substance abuse is understood, we can formulate treatments that correctly target the science behind it all.
To put it simply, drug addiction is a complicated matter. There are so many factors that could put a person at risk for substance abuse in their lifetime. The list goes on and on. It is now known that biology plays a large role in addiction. Drugs affect the brain in many different ways; some of which directly allow addiction and dependence to transpire.
The human brain is supposed to be intelligent and is supposed to help us avoid things that could be detrimental to our survival. Yet how does it allow for something like drug addiction to take place? How can something feel so good but at the same time be so incredibly wrong? The brain is theoretically supposed to be able to help a person tell the difference between right and wrong. However, with drugs it can be a messy gray area. Drugs trick the brain and alter the neurological pathways. By doing so, it can potentially rewire itself. With addiction, the brain is focused on seeking out drugs. It needs those drugs to achieve the high to function. It is a compulsion. The brain can adapt and change in ways where it cannot function without the drug being in the body anymore; due to repeated drug exposure.
One of the pathways that drugs target is the dopaminergic pathway. This pathway includes the nigrostriatal tract, the mesolimbic pathway, and the mesocortical pathway. The pathway that is arguably most important is the mesolimbic pathway. Drugs of abuse repeatedly target and alter this pathway. The mesolimbic pathway begins in the ventral tegmental area (VTA) and terminates in the limbic areas of the brain. This path includes the nucleus accumbens, which has been referred to as the pleasure center of the brain. The dopaminergic pathways are significant when trying to understand the biological reason behind why people use drugs. Dopamine is a critical neurotransmitter found in the brain that is released as a reward during enjoyable situations. The release of dopamine can be motivation to do the pleasurable activity again.
Due to this reward system built into our brains, enjoyable things like eating good food and exercise can be reinforced and the dopamine release can drive us to want to repeat certain actions. Drugs have an uncanny ability to hijack this natural reward pathway; especially in the case of addiction and drug dependence. Drugs of abuse also cause the brain to release various levels of dopamine, which is important in the effect of the high from a drug. This dopamine release feels so good that it can motivate people to use the drugs more often. Frequent drug use can alter the brain to be conditioned to perform in that specific environment. After a while of repeated use of a drug of abuse, it may not be able to function without the drug coursing through the body. This is when someone is dependent on a drug and needs it in order to function. Addiction comes from a compulsive, chronic consumption in vulnerable individuals and the need for the drug can be so strong that it makes it very difficult to treat.
Although it is a challenge to treat addiction, it is not impossible. Addiction usually is, however, a lifelong task. It is a chronic relapsing disorder. One could be sober for so many years and one day fall right back into old habits. The short film Heroin(e), (De Leon & McMillion-Sheldon, 2017), tells the story of three women in the area of Huntington, West Virginia. Someone in the movie discussed being sober for seven months, only to one day fall back into her old ways. In the beginning of the film, it was expressed that Huntington, WV has been nicknamed the drug capital of the United States. Their overdose mortality rate is ten times greater than the national rate. One of the women followed is a first responder. The film shadowed her throughout her typical day on the fire department in Huntington. At one point in the film, she says “twenty years ago, overdoses were few and far between. Nowadays we have five, six, seven overdoses a day”. She also took the time to explain that many of the people afflicted with this disorder in the Huntington area started with prescriptions due to injury. When the pills ran out, a lot of them turned to other drugs to keep the high going.
The Huntington fire department was granted the access to keep Naloxone on board the ambulances and fire trucks to save people from an overdose by the department of health. She described how Naloxone functions briefly. Basically, when one takes an opioid drug, it hooks onto certain receptors in the brain. It can subdue breathing. The drug Naloxone can displace the opiate off of the receptor so that breathing is no longer suppressed and the patient can once again begin breathing again. The issue was posed towards the end of the short film that people in the community felt that drugs such as Naloxone and Narcan were enabling addicts to keep doing what they were doing. The first responder’s argument to that was that she did not care whether she had to administer it one time or 50 times to the same person, it just meant that she is giving that person as many chances to go find treatment that she possibly can. She did not see it as enabling the behavior, but simply as allowing someone more chances to get help.
Treatment for substance abuse and addiction is a long, difficult road. However, with the knowledge in the scientific roots of addiction, there is potential to target the biology behind it all. One way to potentially treat addiction is through exercise. One study, published by Robison, Swenson, Hamilton, and Thanos (2018) details an experiment done on rats. The rats were separated by gender and then were further separated into stationary and exercise groups. The rats that exercised were put on the treadmill for ten minutes at a time over the span of six weeks. The stationary rats stayed in their cage with no physical stimulation. After six weeks, the rats were killed and their brains were analyzed. The researchers were interested in dopamine; specifically, the D1 and D2 receptors. They thought that exercise could have potential benefits on addiction due to its positive effects on so many other things (ie: lessening cognitive decline, improving memory and functioning, mood boosting, etc).
Exercise has already been proven to increase the production of dopamine in the brain so the researchers were curious about the results. In fact, they discovered that the rats that were subjected to involuntary (forced) exercise for six weeks had lessened D1-like binding and increased D2-like binding in both the dorsal and ventral striatum of the brain. The D1 receptor is necessary for the stimulating effects from recreational drugs, such as cocaine. A D2 receptor with dopamine bound to it can modulate dopamine release. This contributed to the rats showing a decrease in seeking out drugs. The results from this experiment were in congruence with past research on this topic as well. This suggests that exercise could be beneficial, when used in conjunction with behavioral therapy or other treatments.
Another study conducted on the benefits of exercise on addiction was performed and published by Smith, Schmidt, Iordanou, and Mustroph (2008). This study was also performed on rats for six weeks. There were sedentary rats and rats with running wheels. After six weeks, a venous catheter was implanted in the rats and they were given doses of cocaine via lever presses; up to ten a day. The rats that were sedentary had more occurrences of infusions versus the exercised rats. They concluded that long term voluntary exercise lowered the sensitivity to the positive reinforcements produced by cocaine in the rats. Simply speaking, the rats that ran the most administered the least amount of cocaine. According to Smith, Schmidt, Iordanou, and Mustroph (2008), exercise is not normally included in typical drug addiction treatment programs, but those that do integrate it claim to have garnered positive results.
Another treatment that could be potentially useful for drug abuse and addiction is immunotherapy and pharmacotherapy, through the use of vaccines. According to Taylor, Laudenbach, Tucker, Jenkins, and Pravetoni (2014), the currently available pharmacotherapy treatments for drug addiction are limited and riddled with side effects. They believe that vaccinations against addictive drugs can positively add to available pharmacotherapy options for addiction. Vaccinations have the ability to prevent the drugs from crossing the blood brain barrier, in turn thwarting the positive reinforcement from the drug in the brain. Vaccines in these studies did not seem to create unfavorable effects on the central nervous system, so they were deemed safe (Zalewska-Kaszubska, 2015). They looked at the effects of both active and passive immunizations. Both were able to keep the addictive chemical out of the brain. Passive immunization was shown to have a positive effect on cocaine overdose. Multiple vaccines have already been sent to trial for nicotine addiction. They work by binding to nicotine in the blood so that it does not reach the brain. According to Carfora, Cassandro, Feola, La Sala, Petrella, and Borriello (2017), vaccinations should be targeted at people who are strongly determined to escape the cycle of drug dependency/addiction. Those that are not motivated to remain adherent could potentially seek out higher concentrations of the drug of abuse to overcome the effects of the vaccine, thus accidentally overdosing.
In conclusion, exercise and vaccinations probably could not cure someone’s dependence or addiction to a drug by themselves. However, based on the findings in the multiple studies, when paired with other forms of treatment, they could potentially help curb the behavior even more than the original treatment alone. There are known biological roots buried in drug addiction and dependence, and treatments need to target those biological components. While these alternative methods for treatment are still in the early stages of research, they show some promise for the future. They could help limit the amount of people suffering from a drug addiction in this country and could benefit those that are already suffering.