Why people develop a drug of choice

This is the last installment of a five part series on the neurobiology of addiction by Jennifer Fernández, PhD. Follow along on Power Over Addiction or Facebook.


representation of addiction

Drugs and compulsive behaviors are used to cope with a variety of problems.

Drug of choice can say a lot about a person or what they’re coping with. People choose drugs that will best help them cope with underlying problems. Sometimes these problems include severe mental illness. Addiction can occur when drugs or compulsive behaviors are relied upon for alleviation from multiple or serious problems.

Alcohol is often sought out by those who have a hard time expressing themselves, especially if coupled with social anxiety. It makes you feel loose and carefree by releasing GABA and suppressing glutamate in the brain. The soothing and disinhibiting effects are also helpful to people in emotional pain, such as someone suffering from grief.  Sometimes people with trauma histories turn to alcohol to soothe their psychic wounds. People with schizophrenia sometimes use alcohol to quiet auditory hallucinations.

Amphetamines give you a rush of pleasure and boost energy and focus by altering norepinephrine and dopamine in the brain. They may be sought out by someone who is depressed and has been unable to feel pleasure for some time. Improved focus may be sought after by someone with ADHD. Anti-psychotic medication can have dulling and flattening side effects and sometimes people with schizophrenia seek out the alertness and energy of stimulants. Nicotine is used by 95% of people with schizophrenia because of its ability to increase concentration and focus.

Opiates may help someone who is feeling irritable, stressed, or moody by blocking endorphin receptor sites in the brain and increasing feelings of euphoria. People who have experienced trauma or are in significant emotional pain may also turn to opiates to help soothe and forget their painful memories. Traumatized people may also turn to dissociatives for their ability to induce out of body experiences.

Hallucinogens and ecstasy create a sense of connection and feelings of warmth and empathy by altering serotonin and norepinephrine receptor sites.  Someone with anxiety or an inability to feel pleasure may turn to these drugs for comfort.

Recreational and pharmaceutical drugs work on the same systems in the brain. So if your drug use is an attempt to self-medicate an underlying problem, speaking to a trained professional can help you find healthier alternatives to cope.

Photo credit: Marrinc

 

Neurotransmitters and Addiction

This is the fourth installment of a five part series on the neurobiology of addiction by Jennifer Fernández, PhD. Follow along on Power Over Addiction or Facebook.


Drugs act on neurotransmitters to increase, decrease, or alter their release or reuptake.

Drugs act on neurotransmitters to increase, decrease, or alter their release or reuptake.

In the previous installment of this series, we learned that dopamine is responsible for feelings of pleasure and euphoria, but it has other functions as well. And dopamine isn’t the only chemical messenger in the brain.

Dopamine is just one of dozens of neurotransmitters. It is the most well known chemical messenger and is responsible for feelings of pleasure, coordination of movement, and logical thinking. It is responsible for “the rush” one feels when they use a recreational drug and it also influences the addictive potential of a drug. It is released when we do things that are important for survival, like sleeping, eating, and having sex. Dopamine sends the message “That feels good! Do it again!”

Norepinephine is one of the brain’s natural stimulants. It is responsible for increased alertness and focus and is involved with learning and memory processes. Norepinephrine is also involved in the fight or flight response. It signals the release of adrenaline in your body to prepare you for survival in the face of imminent danger. It sends the message “Fight!” or “Run!”

GABA (gamma-aminobutyric acid) is the brain’s Valium. It relaxes the brain by suppressing overexcitement or hyperactivity, while allowing us to remain alert and focused. Low levels of GABA are associated with anxiety and seizure.

Glutamate stimulates various activities throughout the brain. We don’t know much about how it is involved in mood regulation.

Serotonin plays several complex roles in the brain. It is involved in regulating mood, sleep, appetite, and sex drive. Low levels of serotonin are associated with aggression, irritability, and depression. Serotonin is also responsible for hallucinations and regulating other neurotransmitters.

Endorphins are the brain’s natural opiates. They influence the perception and control of physical and emotional pain. In addition to pain relief, they are responsible for feelings of well-being, happiness, and euphoria.

Drugs act on these messenger chemicals to increase, decrease, or alter their release or reuptake. Our brain is wired to recognize these chemicals and accept their messages. The difference is that drugs relay the message better, faster, and in a much more intense way. Research shows us that life experiences affect the development of the brain, including how neurotransmitters work. For example, someone who has experienced trauma may find it difficult to feel pleasure or regulate their mood due to low levels of dopamine and serotonin. This may cause them to turn to externally supplied chemicals to balance the levels of neurotransmitters in their brain.

The next, and final, installment of this series will explain why some people turn to recreational drugs in an attempt to balance the chemical messengers of the brain.

Photo credit: Life Mental Health

This is your brain on drugs. For real.

This is the third installment of a five part series on the neurobiology of addiction by Jennifer Fernández, PhD. Follow along on Power Over Addiction or Facebook.


This is not your brain on drugs. These are burnt eggs.

This is not your brain on drugs. These are burnt eggs.

Addiction is scary. It has caused pain in many people’s lives and has cost families and governments trillions of dollars to treat and prevent. It’s no surprise that social service agencies want to educate the general population about the harms of addiction. You may have seen this public service announcement comparing the addicted brain to fried eggs. The image is powerful, yes, but it is not educational. This is what actually happens in your brain when you take drugs.

Neurons generate messages that travel between cells in the brain.

Neurons generate messages that travel between cells in the brain.

Above is an image of a neuron. Our brain is filled with billions of these nerve cells and fibers. They contain genetic information and also serve as messengers. They transmit information through fibers from one cell to another via electrical charges. Neurons generate messenger chemicals, or neurotransmitters, to transmit information from cell to cell. The electrical charge travels through the dendrites, cell body (or soma), axon, and terminal bud down to the synapse, the gap between neurons where the magic happens. Neurotransmitters live in the terminal bud of neurons. An electrical charge comes through the neuron and releases the messenger chemicals. The chemicals then float across the synapse and attach to the neighboring cell for a short amount of time in a process called neurotransmission. Once the message has been relayed, they return to their home cell. This process is called reuptake. For example, if you were to burn your hand on the stove, nerve cells in your muscles would send a message to the neurons in your brain saying, “Ouch!” Your brain sends a message back down to the muscles in your arm to pull your hand back. At the same time, the message from your burning hand also alerts your brain to release endorphins, the brain’s natural pain reliever. The endorphins do their job and relieve the pain long enough so you can think to run cold water over your hand. Once the message has been communicated, the endorphins return to their home cell until the next electrical charge commands them to be released.

 

THIS is your brain on drugs.

THIS is your brain on drugs.

Above we have a close up of the synapse, the gap between neurons, and what happens when cocaine is present in the brain. The red arrows show the process of reuptake. The neurotransmitter dopamine has been released into the synapse to send a message to the neighboring cell. Once dopamine has completed its task, it attempts to go back home, but cocaine is blocking the way. Since dopamine can’t go back home it goes back to doing it’s job, binding to the neighboring cell. Dopamine’s loitering, so to speak, is what causes feelings of intense pleasure and euphoria.

Dopamine is only one of dozens of neurotransmitters in the brain. In the next installment, we identify the major neurotransmitters involved with drug use.

Photo credits: burnt eggs by incredibledictu, neuron, and neurotransmission by NIH

 

The Neurobiology of Addiction

Brain_Broccoli_by_faiizeThis is the first installment of a five part series on the neurobiology of addiction by Jennifer Fernández, PhD. Follow along on Power Over Addiction or Facebook.


Addiction is a biopsychosocial phenomenon that affects over 20 million people in the United States. The factors that cause addiction are not yet well understood, with some arguing that it is a disease and others suggesting it’s more complicated than that.

But we can identify some predictors for addiction and we do understand the impact it has on the brain.

This five part series will primarily focus on current understanding about the brain structures and neurotransmitters involved in addiction. We’ll also look at the interaction specific drugs have with neurotransmitters in the brain and how this accounts for preferences in drug selection. We’ll start with an overview of addiction theories then dive into the neurocircuitry and neurobiology of addiction. We’ll conclude by looking at the effect of drugs on neurotransmitters in the brain and discuss why one develops a drug of choice.

Theories of addiction

Although we don’t fully understand addiction, there are lots of theories that attempt to explain it. The most popular one is the disease model. It explains that addiction has a biological origin that causes changes in the brain. This model also accounts for the heredity of addiction, or genetic predisposition. Studies of twins who have been separated at birth show that they are likely to develop addictions, despite growing up in different home environments.

You may have also heard addiction described as a hijacker of the reward center of the brain. Brain imaging studies show that overuse of drugs or compulsive behaviors “hijack” the reward system and can lead to changes in the brain that make it difficult to experience pleasure as one did before.

Then there’s the self-medication hypothesis. It posits that people use drugs to help them cope with physical and/or emotional pain. It helps explain why people turn to specific drugs or compulsive behaviors to help them deal with things like depression, chronic pain, trauma, or grief.

But the best way to explain addiction is as a biopsychosocial phenomenon. We know that addiction has a biological component. It causes temporary and permanent changes in the brain and body. We also know there is a psychological component: an inability to cope with distressing emotions. The social component of addiction is related to peer culture, as they influence what you use, how you use it, or how (not) to deal with your emotions.

In the question about nature versus nurture, the answer might just be nature and nurture. Drugs affect us biologically and we may even be genetically predisposed to those effects. Your parents, family, friends, or lovers may have modeled addictive behaviors or inability to cope with emotions in a healthy manner.

The next installment of this series will focus on the neurocircuitry of addiction.

Photo credit: Faiize

 

Zap away cocaine addiction with lasers! or magnets!

brain laserResearchers at the National Institute of Health and UCSF claim to have stopped and started cocaine addiction in rats with the use of laser stimulation to the prefrontal cortex, the brain region where decision making and impulse control take place. “When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone,” said Antonello Bonci, MD, scientific director of the research program at the NIH’s National Institute on Drug Abuse (NIDA).

Studies with human subjects are already being designed ,according to Billy Chen, the lead researcher. But lasers wouldn’t be used with human participants. Prefrontal cortex stimulation would be achieved through the use of transcranial magnetic stimulation (TMS) which is currently being used as a treatment for depression. It should be noted that the jury is still out on the efficacy of TMS to treat depression, as reported in the journals Current Pharmaceutical Design and Pharmacology and Therapeutics.

This is all very interesting, but addiction is more than biological. People don’t become addicted to a drug because of their neuroanatomy and neurochemical environment. It’s more complex than that. It seems unclear to me what exactly changes in the prefrontal cortex due to this stimulation. Does it make a person (or a rat) more mature and logical in their decision making process? If that’s the case, there may be many uses for this technology! Needless to say, I’m skeptical.

You can read the abstract and view supplemental information about the study in Nature.

Thanks to Jim Wiggins for sharing this article.

Photo credit: Block and Tackle Productions

Researchers stop stress-related relapse in rats

stressWe all deal with stress and have to learn methods to reduce and manage the stressors that life throws at us. But for someone with an addiction, day to day stressors can have a disastrous impact. Stress can trigger relapse, especially early in the recovery phase of addiction when new coping skills are being introduced and a person experiments with various strategies to find those best suited to their lifestyle needs.

Past research has focused on the psychological and emotional mechanisms involved in stress-induced relapse and there has been some speculation about the brain structures and neurotransmitters involved, but now researchers from Brown University and the University of Pennsylvania have found that by blocking kappa opioid receptors in the ventral tegmental area (VTA), rats under stress do not relapse on cocaine.

The VTA is the brain structure responsible for rewarding the fulfillment of basic needs, like hunger, sleep, and love. It contains dopamine releasing neurons that communicate with other brain structures, like the nucleus accumbens and the pre-frontal cortex when a basic need is met. It’s also involved in the rewarding release of dopamine when one uses a drug. GABA is an inhibitory neurotransmitter that slows down the release of dopamine in the VTA of a healthy brain.

Kappa opioid receptors are released in the VTA during stress and interrupt GABA’s process. By blocking those receptors in rats, researchers found they were able to resist relapsing on cocaine after five minutes of stressful exercise. “If we understand how kappa opioid receptor antagonists are interfering with the reinstatement of drug seeking we can target that process,” Kauer said. “We’re at the point of coming to understand the processes and possible therapeutic targets. Remarkably, this has worked.”

This is exciting news in the field of addiction as we are learning more and more about the neurobiological underpinnings of this devastating disorder. Researchers are especially excited about the potential to develop prescription drugs to help prevent relapse, and although this prospect may help people overcome their addiction, it is important to remember that addiction is more than just neurobiological processes. People overcoming addiction also need to learn emotional regulation and healthy alternatives to fulfill unmet needs in their lifestyles.

You can read more about this study here.

Photo credit: bottled_void

Is internet addiction real?

If internet use interferes with one’s life and ability to function, internet addiction or compulsive internet use may be a concern.

Internet Addiction

Although there is debate in the academic world about the authenticity of internet addiction there is no dispute that, for some people, excessive internet use can cause distress, strife, and disruption in their ability to function. Internet addiction is somewhat of a misnomer and compulsive internet use seems to capture the nature of the disorder more accurately. It’s compulsive because use of the internet acts as a substitute for an unmet lifestyle need. For example, someone who suffers from depression or anxiety may turn to the fantasy world of the internet to escape those uncomfortable emotions. Obviously this is also true of drug addictions, and although a recent study shows differences in the brain anatomy of excessive internet users, the results are inconclusive.

The Center for Internet Addictions proposes  the following diagnostic criteria for internet addiction for users who have experienced four or more of the following symptoms in the last month:

  • Feeling preoccupied with the Internet or online services and thinking about it while off line
  • Feeling a need to spend more and more time online to achieve satisfaction
  • Inability to control online use
  • Feeling restless or irritable when attempting to cut down or stop online use
  • Going online to escape problems or relieve feelings such as helplessness, guilt, anxiety or depression
  • Lying to family members or friends to conceal how often and how long you stay online
  • Risking the loss of a significant relationship, job, or educational or career opportunity because of online use
  • Continuing use even after spending too much money on online fees
  • Going through withdrawal when offline, displaying symptoms such as increased depression, moodiness, or irritability
  • Staying online longer than originally intended

Compulsive internet use can take on several forms:

  • cybersex & pornography
  • online relationships
  • gaming
  • compulsive shopping

Regardless of the biological underpinnings of excessive internet use, it is clear that people experience distress and disruption to their lives when they compulsively turn to the internet for relief. If you think your internet usage is compulsive, contact a mental health professional for an evaluation. It is highly likely that you are using the internet to cope with an underlying issue.

¿Es real la adicción a internet?

Para leer este y otros de mis artículos en español visite articulando.com.uy

Photo credit: Federico Morando

Put this in your shot glass and inhale it!

 vaportiniWatch out, America! The Vaportini is coming to a store near you. That’s right, why drink alcohol when you can INHALE it?

All jokes aside, this method of consuming alcohol can be extremely dangerous. Apparently researchers create alcohol addiction in rats by exposing them to the vapor (they don’t like the taste of alcohol). Not only are the addictive qualities of alcohol increased, but the risks are as well. Rats exposed to alcohol vapor demonstrate anxious behaviors and deficits in the reward center of the brain. In humans, reward center deficits can lead to anxiety, depression, and decreased motivation.

The dangers associated with alcohol intoxication also increase with this method of consumption. Inhaling alcohol bypasses the digestive system which means two things: 1. alcohol is absorbed quickly into the bloodstream through the vessels in your nose and lungs causing a rapid and more intense buzz, and 2. protective measures of the digestive system such as slower absorption rates and vomiting become obsolete and may increase the risk of alcohol poisoning.

This isn’t the first time alcohol inhalers hit the market. In 2004 AWOL (Alcohol Without Liquid) was introduced in the U.S. and quickly banned in 22 states. AWOL sold for $300 a unit, but at $35 a unit for the Vaportini, access is granted to many more people, especially college kids who are looking for a novel way to consume alcohol.

Circumcision of the brain?

opiate addiction

Photo by Domiriel

Physicians in China performed brain surgeries to treat opiate addiction by destroying the nucleus accumbens, the pleasure center of the brain. The procedure is called stereotactic ablation of the nucleus accumbens, which means brain tissue is burned away. Although the procedure was banned in 2004, surgeries continued in the name of research.

The hope was that by destroying the part of our brain responsible for pleasure associated with drug use (among other things) the desire for using drugs would diminish. Results published in World Neurosurgery last October showed that 5 years after the surgery, 53% of participants had relapsed and were addicted to opiates again. In addition, 21% of participants experienced memory deficits and 18% experienced loss of motivation. These side effects are permanent due to the irreversible nature of the treatment. Read more about this controversial surgery here.

It is clear that addiction has devastating effects, but how far are we willing to go to treat it? Is it fair to ask addicts to potentially sacrifice pleasure and motivation to kick their habit? Some of the participants of this study were as young as 19 years old and had been addicted to heroin for 3 years. Granted, this research was conducted in China, a place where the death penalty is considered a suitable intervention for addiction. Is it ethical to have moral standards influence scientific research? Where do we draw the line?

Drug Tolerance Explained

toleranceOur brain thrives on novelty and dopamine helps us store information about novel situations.  We know that dopamine is released when we receive a reward, but it is also involved in noting unexpected rewards. If you get more juice than you anticipated, your brain releases dopamine and sends it to the anterior cingulate in your frontal cortex, a brain region responsible for anticipating rewards and making decisions. Get less juice than you anticipated and, again, your brain will encode the information, but this time, by sending less dopamine to the anterior cingulate. If you get the same amount of juice you expected, no dopamine is released. This mechanism enables us to recognize patterns and learn which behaviors lead to risk versus reward.

How does this translate into drug and behavioral tolerance? When you use cocaine for the first time, your brain registers it as a pleasurable experience. After using it a few more times, you might notice that you don’t experience the same level of euphoria as before. That’s because the experience has lost novelty and your brain has learned to recognize the pattern. In other words, dopamine isn’t released since there isn’t anything novel about the experience. Tolerance is born. In order to achieve euphoria from cocaine, you must now use more.

The same process occurs with compulsive behaviors. The first few times you shoplift (and don’t get caught) you experience relief and pleasure, but with subsequent trials you notice a decrease in the euphoria you experience. So, you start shoplifting more frequently.

NoteThere are many neurobiological mechanisms at play in addiction and compulsive behaviors and the role of dopamine in addiction and tolerance is just one facet of a complex biopsychosocial phenomenon.