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

 

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

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.

This is your brain on dopamine

Dopamine_PathwaysDopamine is a neurotransmitter responsible for movement, pleasure, motivation, and cognitive processes, such as learning. For the purposes of understanding its role in addiction, let’s concentrate on pleasure and motivation.

Whenever we do something that propagates the advancement of our species, dopamine is released in order to motivate repetition of the action. When we sleep, eat, and have sex dopamine is released in our brain and the message is, “That was great, do it again!” We also release dopamine whenever we find something pleasurable. Be it 18th century poetry, heroin, or Radiohead, our brain will release dopamine to encode the stimulus as something that brings us pleasure.

Dopamine not only serves to categorize the good things we encounter in life, it also programs our pre-frontal cortex (the part of the brain involved in judgement and decision making) to alert us when the pleasurable stimulus is available. If your brain cells could talk, it might sound something like, “OMG! There’s a flyer on that lamppost for a Radiohead concert. Go look at it!” In other words, we become hyperaware of opportunities for engaging in behaviors that bring us pleasure. In fact, a study on people with alcoholism found they were more likely to spot alcoholic beverages in a busy photograph than people who don’t have problems with alcohol.

When we consume substances, it makes us feel good because our brains release dopamine, but drugs elicit a higher amount of dopamine release than is necessary. This is part of what causes experiences of euphoria and feeling high. Sometimes the amount of dopamine released is so great, the chemicals in our brain become unbalanced and we may experience hangover or withdrawal. In time, our brain regains chemical equilibrium. However, if one abuses substances, the brain may develop a tolerance (meaning the person needs to use greater amounts to get high) or dependence on the substance as a source of dopamine. If one becomes dependent on a drug, it may take some time for the brain to regain equilibrium and the person may experience extreme physical discomfort and emotional distress when they aren’t using. The period of re-calibration depends on the amount, type, and frequency of the drug used. It’s always a good idea to be under medical supervision and receive support from friends, family, and a mental health professional if you’re dependent on a drug and want to stop or decrease your use.

The mechanism of tolerance is also evident in impulse control disorders, such as sex addiction, kleptomania, and compulsive gambling. Although it doesn’t appear that persons with an impulse control disorder undergo the same intensity of withdrawal that persons addicted to substances experience, there can certainly be a period of re-calibration of dopamine receptors during which a person feels irritable and agitated after stopping a behavior.

Based on the information presented here, it appears that we are all hard-wired to become addicts and you may be asking yourself, “If this is true, why do some people become addicted and others don’t?” This is a really good question and the answer is “We don’t really know.” We can predict the likelihood of someone becoming an addict based on factors such as first age of substance use and family history of addiction, and we know that a lack of social support and coping strategies (especially when coupled with mental illness) can also lead to addiction, but there is no conclusive answer to date.

The best ways to prevent addiction are to educate yourself about the substances you use (or to abstain from substance use altogether) and to be mindful about the choices you make. If you have a mental illness, ensuring that you are getting appropriate treatment and maintaining social support are good preventative measures.