Cobbers on the Brain

People with drug addiction not only suffer from the effects of the drug, but also a negative connotation that surrounds addiction. If I were to ask you to imagine someone who suffers from drug addiction, you, like many other people, would create the image of a “junkie” in your mind. This is part of the problem with addiction, one of many problems that will be discussed later. Many people believe that addiction is a choice; little do they know that drugs have the ability to rewire a brain, forcing people to seek those drugs above all else.

The Reward System

Drugs affect the brain’s reward system. Dopamine is the main neurotransmitter involved in this reward and motivation pathway. Drugs cause dopamine release, creating a pleasurable feeling. There are two dopamine receptors that tie in with the addiction dilemma. The first dopamine receptor, D1, is involved with direct activation of the reward pathway, and it has a lower binding affinity for dopamine. The other receptor, D2, is involved with indirect punishment and inhibition of the pathway; it also has a higher binding affinity for dopamine.

Certain brain regions are involved in this reward pathway. In the addiction story, the two major regions are the nucleus accumbens (NAc) and the ventral tegmental area (VTA). The VTA is the site of neurons that produce dopamine, which tells the individual whether a stimulus (drug of abuse) is rewarding or aversive¹. VTA neurons target the NAc, which causes the activation of D1 and D2 receptors creating the rewarding effects of drugs or natural rewards. Under normal conditions, the reward pathway controls an individual’s responses to natural rewards, such as food, sex, and social interactions¹. This pathway is important in determining an individual’s motivation and their incentive drive¹. Stimulation of the reward pathway tells the individual to repeat what it just did to get that reward¹.

But, drug induced stimulation of this pathway could lead to addiction. The VTA-NAc pathway is activated with each drug use². Drugs, such as opiates, bind to receptors and send signals to dopamine terminals to release more dopamine². This dopamine release, then, creates a pleasurable feeling that causes individuals to become addicted to that drug, seeking it out over and over for that pleasurable feeling. Repeated use of drugs cause an over-activation of dopamine and stimulation of the receptors involved, thus impairing the regulatory responses for which the brain is responsible². If the regulatory response is impaired, then it is nearly impossible to stop using the drugs.

Therefore, drug addiction should not be viewed as a repeated choice. You are your brain, and your brain is telling you to seek those drugs for the pleasurable feeling. Each drug has a different mechanism, but they all increase the activity of the reward pathway by increasing dopamine transmission. Drug addiction is truly a disease of the brain, not a choice.

1. http://neuroscience.mssm.edu/nestler/brainRewardpathways.html
2. https://www.drugabuse.gov/publications/teaching-packets/neurobiology-drug-addiction/section-iii-action-heroin-morphine/3-morphine-binding-within-reward

“Don’t Do Drugs”

The first time I heard this message I was in kindergarten, and I didn’t even know what drugs were. As I climbed up the elementary school ladder, I slowly began to understand the “basics” of drugs. I eventually came to the conclusion that there were two different “types” of drugs in the world:

• The “good” drugs that you take when you are sick to make you feel better
  AND
• The “bad” drugs that you take if you want to ruin your life

That’s what I was told.

As a child, this thought becomes ingrained in your mind, and how can it not? From the haunting textbook images of individuals before and after taking “bad” drugs to the countless warnings you hear from concerned parents, teachers, and the media, it is no surprise that you begin to develop an image of what a stereotypical drug addict looks like:

You think to yourself…

• Drug addicts have:
  • Rotten/Missing Teeth
  • Wrinkled/Scabbed Skin
  • Dry/Damaged Hair
• Drug addicts are:
  • Criminals
  • Lazy/Unproductive
  • Liars/Manipulators

You begin to tell yourself that there’s no way that you would ever become a drug addict. You’re not “that kind of person.” That’s where you’re wrong. 

Anyone can be a drug addict .

Individuals develop this preconceived notion that they could never become a drug addict, and that even if they try a drug, just once, they won’t get hooked.

The fact of the matter is, no one knows how drugs of abuse will affect them until they try them, and for many, after just once, it’s too late. In fact, one’s genetic makeup accounts for 50% of their risk of becoming an addict. The other 50% chance is the result of one’s environment, specifically whether or not one exposes themselves to drugs of abuse.

So why are drugs so hard to quit?

They change the way your brain works. 

The brain has a specific system that drugs of abuse “manipulate”: The Mesolimbic Pathway

• This pathway is involved in the feelings of reward that often accompany naturally rewarding things such as food, sex, and caffeine.
• This reward comes in the form of the “feel-good” neurotransmitter known as dopamine.
• Dopamine originates in cell bodies within the ventral tegmental area (VTA) of the brain. The axons that release dopamine leave the VTA and terminate in a separate area of the brain known as the nucleus accumbens (NAc).
• In addition to the NAc, dopaminergic axons can also be found in the hippocampus (involved in memory), the amygdala (involved in emotional responses), and the prefrontal cortex (involved in cognitive functioning).

• When an individual experiences something rewarding, the concentration of dopamine within these brain regions increases, and they immediately experience a sense euphoria.
• Drugs of abuse in particular have a way of making this euphoric “high” last for a prolonged period of time.
  • For example, cocaine blocks the re-uptake of dopamine so that it is able to stimulate the reward system for a longer period of time, inducing a more intense “high”.
• Drugs of abuse increase the reward to a certain extent:
  • Whenever a drug of abuse is taken, molecules known as dynorphins bind to specialized receptors in the brain known as kappa opioid receptors.

    

    • The binding of dynorphins to these receptors inhibits the release of dopamine into the reward pathway.
      • Therefore, after repeated exposure to the drug of choice, less and less dopamine is released into the reward pathway, and the “high” decreases.
        • The individual’s brain does not understand this, however, as it has become re-wired to expect the “high” that it has previously experienced.

          

        • The individual will begin to crave the drug of abuse intensely, and will go through withdrawal symptoms if it is not administered.
          • To satisfy the brain, the individual will need to take more of the drug of choice to deliver the same amount of reward….

            ……… and there you have it, you’ve become addicted.

So what’s the take home message?

It’s exactly what you’ve been hearing since you were in kindergarten:

Don’t do drugs.

• Individuals often do not know how drugs will affect them, until it’s too late.
  • No one is “immune” to becoming a drug addict.
  • And once you’re addicted your brain will change itself in a way to ensure that you’ll stay hooked.
    • But, quitting isn’t impossible!

The road to recovery isn’t an easy one, but it is possible. 

There are many resources that you can use to help yourself or a loved one on the road to recovery:

• Substance Abuse and Mental Health Services Association
  • https://www.samhsa.gov/find-help/national-helpline
• American Addiction Centers
  • This link provides a list of local rehabilitation and treatment services by state
    • https://drugabuse.com/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1920543/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898681/

What is Drug Addiction:

Drug addiction is a medical condition characterized by the compulsive seeking and taking of drugs for rewarding stimulus despite adverse consequences or loss of control over drug use. Drug addiction occurs due to long-lasting changes that occur in the brain from prolonged use, but not everyone is affected in the same way. Genetics account for 50% of an individual’s variability in addiction vulnerability, while the other 50% comes from a wide array of environmental factors. Once an individual becomes addicted, it can be extremely difficult to stop, and the chance of relapse will continue to be present.

Why Are These Drugs So Addictive?

Drugs can be so addictive because they hack the reward pathway in the brain. The reward pathway is a pathway in the brain that enhances certain behaviors that are necessary for survival, such as eating, drinking, sex, and social interaction. Drugs turn these survival needs into drug needs.

The reward pathway involves the transmission of dopamine. Dopamine is release when an individual engages in pleasurable activities and binds to an adjacent neuron in the brain. The binding of dopamine to a dopamine receptor is what gives a pleasurable feeling or rewarding effect, making you want to continue to do that activity. Eventually this dopamine is taken back into the neuron by a molecule called dopamine transporter.

Drugs abuse this system by increasing the amount of dopamine present in the synaptic cleft. Some drug increase the number of action potentials which leads to increased dopamine release, other drugs increase dopamine without the action potential, and some block the reuptake of the dopamine back into the neuron. Whatever the method, they all work to keep the concentration of dopamine high in the synaptic cleft for an extended period, causing the prolonged and intense euphoria described by drug use. These repeated exposures to dopamine surges desensitize the reward system which makes those normal, necessary action for survival no longer a priority as drugs are the only rewarding thing. With continued drug exposure, the reward system continues to become more and more desensitized requiring more drug for the same effect. This is what can eventually lead to overdose.

What Can You Do?

It is important that we remember that individual who deal with addiction are struggling with a neurological illness that so far appears to be irreversible. We as a society need to learn to treat this as any other neurological disease and help those who are struggling as this is far more than just a choice as the brain structure is literally altered. This is why it is important that we avoid street drugs with all costs and take medically prescribed drugs with extreme caution.

The opioid epidemic has become an enormous issue nationally. In the United States, a public health emergency was declared in 2017 in relation to the opioid crisis. Based on data from 2016 and 2017, more than 130 people die each day from opioids, 11.4 million people have abused prescription opioids, and 42,249 people have died from opioid overdose. This issue is harming individuals all over the country and has everlasting effects. In order to combat this issue, there must be more knowledge, less stigma, and a greater understanding of addiction as a whole in order to fight this crisis.

There are many misconceptions about addiction, specifically opioid addiction, including “Why don’t they just quit?” or “Why do something that causes you so much harm when you could just choose not to?”. Even though it may seem easy to choose a life without opioids to an outsider, it becomes less and less of a choice when looking at the brain of an addicted individual. Addiction vulnerability of each individual is 50% accounted for by genetic factors, made up of hundred of genetic variations. The remaining 50% is accounted for by various combinations of environmental factors, causing an individual to be more vulnerable to addiction. Some risk factors that contribute to opioid addiction are:

• “gateway” drugs such as prescription medication, marijuana, alcohol, and nicotine
• anxiety or depression
• other psychiatric disorders
• exposure to abuse or trauma
• family or friends addicted to drugs
• access to addictive drugs
• starting substance abuse at a young age
• poverty

There are many reasons why an individual may be more predisposed to becoming an addict. In addition, there are specific changes in the brain that occur in order to cause specific symptoms of addiction to occur if an addicted individual tries to “quit”, such as craving, withdrawal, and relapse.

These changes in the brain include changes to certain nerve cells due to drug exposure, causing the neurons to respond differently to drugs, changes that occur in response to addiction, such as altered gene transcription, synaptic plasticity, and neurotrophic mechanisms, and changes in key neural substrates or brain regions of behavioral memory. These alterations cause caring and relapse as there are differences in the memory circuits due to addictive drugs.

Since it is clear that addiction is not necessarily a “choice”, the U.S. population as a whole must become more aware of the opioid crisis in order to begin finding solutions.  In order to target the opioid epidemic, there must be a greater awareness of how addiction occurs, what is happening in the brains of addicted individuals, and how to target therapies and treatments to each specific individual. Stated in the facts above, the opioid epidemic is affecting millions all over the nation and must be addressed. By understanding the factors that play in to addiction and gaining knowledge about each addict’s personal situation, treatments and solutions may become more accessible.

https://www.centeronaddiction.org/addiction/addiction-risk-factors
https://www.hhs.gov/opioids/about-the-epidemic/index.html