Category Archives: dopamine

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.

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.

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.

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