Drug addiction and the brain

April 25, 2014

Drug addiction and the brain-Effects of dopamine on addiction

why dopamine-producing drugs are so addictive is that they have the ability to constantly fill a need for more dopamine.

In the previous article we stated that dopamine is an inhibitory neurotransmitter, meaning that when it finds its way to its receptor sites, it blocks the tendency of that neuron to fire. We also noted that it is strongly associated with reward mechanisms in the brain. That aside new research on the brain is showing that addiction is a matter of memories, and recovery is a slow process in which the influence of those memories is diminished.

Further studies have also shown that addictive drugs stimulate a reward circuit in the brain. The circuit provides incentives for action by registering the value of important experiences. Rewarding experiences trigger the release of the brain chemical dopamine, telling the brain “do it again.” What makes permanent recovery difficult is drug-induced change that creates lasting memories linking the drug to a pleasurable reward.

Drug addiction and the brain-Brain circuits

Addiction involves many of the same brain circuits that govern learning and memory. Long-term memories are formed by the activity of brain substances called transcription factors. All perceived rewards, including drugs, increase the concentration of transcription factors. So repeatedly taking drugs can change the brain cells and make the memory of the pleasurable effects very strong. Even after transcription factor levels return to normal, addicts may remain hypersensitive to the drug and the cues that predict its presence. This can heighten the risk of relapse in addicts long after they stop taking the drug.

Knowing more about how addiction works in the brain has not yet given us any effective new treatments, but it has suggested new possibilities while providing a better understanding of how the available treatments work. The hardest job will be finding substances that lower the risk of addiction but do not interfere with responses to natural rewards. So far there is little evidence that any one type of therapy works better for addiction than another.

Drug addiction and the brain-Brain Chemistry

It has been demonstrated times and again that drug addiction is a powerful force that can take control of the lives of users. In the past, addiction was thought to be a weakness of character or just misbehavior, but in recent decades research has increasingly found that addiction to drugs like cocaine, heroin and methamphetamine is a matter of brain chemistry.

Experts at the National Institute on Drug Abuse, says that the way a brain becomes addicted to a drug is related to how a drug increases levels of the naturally-occurring neurotransmitter dopamine, which modulates the brain’s ability to perceive reward reinforcement. The pleasure sensation that the brain gets when dopamine levels are elevated creates the motivation for us to proactively perform actions that are indispensable to our survival for example eating or procreation. Dopamine is what conditions us to do the things we need to do.

Drug addiction and the brain-Neurochemical reward

Using addictive drugs floods the limbic brain with dopamine taking it up to as much as five or 10 times the normal level. With these levels elevated, the user’s brain begins to associate the drug with an outsize neurochemical reward. Over time, by artificially raising the amount of dopamine our brains think is normal, the drugs create a need that only they can meet.

For instance, when a drug produce increases in dopamine in these limbic areas of the brain, then your brain is going to understand that signal as something that is very reinforcing, and will learn it very fast so that the next time you get exposed to that stimuli, your brain already has learned that reinforcing instantly. Over time, the consistently high levels of dopamine create plastic changes to the brain, desensitizing neurons so that they are less affected by it, and decreasing the number of receptors. That leads to the process of addiction, wherein a person loses control and is left with an intense drive to compulsively take the drug.

According to experts the reason why dopamine-producing drugs are so addictive is that they have the ability to constantly fill a need for more dopamine. So a person may take a hit of cocaine, snort it, it increases dopamine, takes a second, it increases dopamine, third, fourth, fifth, sixth. So there’s never that decrease that ultimately leads to the satiety. Addiction has to do with the brain’s expectations. An emerging idea is that drugs basically hijack the brain’s normal computational enjoyment and reward mechanisms.

For example let’s say you’re happy about a great chocolate ice cream and over time you learn to expect that the chocolate ice cream is really great and you have no more dopamine released in expectation of that when you receive it. Nevertheless if you take an addictive drug you can never learn to expect it because the drug itself will release an extra kick of dopamine. And when that happens, the value of that drug keeps increasing because now you’re learning that wow my expectations were violated, therefore this must be much more valuable than what I thought before. So what ends up happening is that dopamine system gets hijacked by these drugs.

It must be noted that there are other components to addiction like genetics and age of exposure which is why not everyone who takes drugs becomes an addict. Approximately 50% of the vulnerability of a person to become addicted is genetically determined, and research indicates that if a person is exposed to drugs in early adolescence they are much more likely to become addicted than if they were exposed to the same drugs as an adult.

Drug addiction and the brain-Take away

One of the key functions of the neurotransmitter dopamine is to create feelings of pleasure that our brains associate with necessary physiological actions like eating and procreating. We are driven to perform these vital functions because our brains are conditioned to expect the dopamine rush that accompanies them.

Addictive drugs flood the brain with dopamine and condition us to expect artificially high levels of the neurotransmitter. Over time, the user’s brain requires more dopamine than it can naturally produce, and it becomes dependent on the drug, which never actually satisfies the need it, has created.

AWAREmed Health and Wellness Resource Center under Doctor Akoury is a facility run by experts headed by doctor Akoury, for proper care and healing of whatever kind of addiction and whatever the level of addiction you need caring experts who will focus on Neuroendocrine Restoration (NER) to reinstate normality through realization of the oneness of Spirit, Mind, and Body, Unifying the threesome. This kind of treatment can only be found at AWAREmed. Reach out for help and get your life back with real professionals.

Drug addiction and the brain-Effects of dopamine on addiction

Opioid abuse and its effects to the brain reward system

March 19, 2014

Opioid abuse and its effects to the brain reward system-How does the reward center in the brain work?

The brain is the life controller and must not be affected by opioid addiction or abuse

Life is the most precious and price less gift humanity has. This is only useful and meaning full with proper functioning brain. We all understand that the brain is certainly a busy little organ yet it is on duty tirelessly for life without taking any vacation, the moment it possess for whatever reason life ends or serenity is rearranged. Despite it busy roles in driving the body; it knows fun and pleasure when it sees it. When an external stimulus, such as a particular food or a potential mate, has been encountered and deemed a pleasurable sensation, the cerebral cortex signals the ventral tegmental area of the brain to release the chemical dopamine into the amygdala, the prefrontal cortex and the nucleus acumens. These latter regions of the brain make up the reward system. These areas work in conjunction to deliver a sense of pleasure and focus the attention of the individual so that he or she learns to repeat the behavior once more. Researchers theorize that this is how behaviors necessary for survival, such as reproduction and eating, are learned.

Interestingly, the reward center doesn’t kick into gear only when we eat something delicious or meet a potential new love interest. It turns out that generosity can be quite a kick too! MRI studies have revealed that when we perform an act of kindness, the brain’s reward center is aroused and we experience feelings of pleasure. The brain is flooded with happiness-inducing dopamine whenever we give a homeless person some money or help out someone in need. A study conducted in 2008 confirmed the belief that spending money on other people can result in elevated feelings of happiness for the giver.

It might not be all fun and games for the reward center, however, a recent study came to a startling conclusion that the brain’s reward center responds to bad experiences as well as good. Doing something scary or even merely thinking about it can trigger a release of dopamine. In essence, dopamine isn’t just triggered by fun and pleasurable events. Negative things can do the trick too.

Opioid abuse and its effects to the brain reward system-Reward pathway

The most important reward pathway in brain is the mesolimbic dopamine system. This circuit (VTA-NAc) is a key detector of a rewarding stimulus. Under normal conditions, the circuit controls an individual’s responses to natural rewards, such as food, sex, and social interactions, and is therefore an important determinant of motivation and incentive drive. In simplistic terms, activation of the pathway tells the individual to repeat what it just did to get that reward. It also tells the memory centers in the brain to pay particular attention to all features of that rewarding experience, so it can be repeated in the future. Not surprisingly, it is a very old pathway from an evolutionary point of view. The use of dopamine neurons to mediate behavioral responses to natural rewards is seen in worms and flies, which evolved 1-2 billion years ago.

The VTA-NAc pathway is part of a series of parallel, integrated circuits, which involve several other key brain regions.

The VTA is the site of dopaminergic neurons, which tell the organism whether an environmental stimulus (natural reward, drug of abuse, stress) is rewarding or aversive.

The NAc, also called ventral striatum, is a principle target of VTA dopamine neurons. This region mediates the rewarding effects of natural rewards and drugs of abuse.

The amygdala is particularly important for conditioned forms of learning. It helps an organism establish associations between environmental cues and whether or not that particular experience was rewarding or aversive, for example, remembering what accompanied finding food or fleeing a predator. It also interacts with the VTA-NAc pathway to determine the rewarding or aversive value of an environmental stimulus (natural reward, drug of abuse, stress).

The hippocampus is critical for declarative memory, the memory of persons, places, or things. Along with the amygdala, it establishes memories of drug experiences which are important mediators of relapse.

The hypothalamus is important for coordinating an individual’s interest in rewards with the body’s physiological state. This region integrates brain function with the physiological needs of the organism.

Probably the most important, but least understood, are frontal regions of cerebral cortex, such as medial prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex, which provide executive control over choices made in the environment (for example, whether to seek a reward).

The locus coeruleus is the primary site of noradrenergic neurons in the brain, which pervasively modulate brain function to regulate the state of activation and mood of the organism.

The dorsal raphe is the primary site of serotonergic neurons in the brain, which, like noradrenergic neurons, pervasively modulate brain function to regulate the state of activation and mood of the organism.

Of course, these various brain regions, and many more, do not function separately. Rather, they function in a highly inter-related manner and mediate an individual’s responses to a range of environmental stimuli.

Opioid abuse and its effects to the brain reward system-What are opioids?

Opioids are medications that relieve pain. They reduce the intensity of pain signals reaching the brain and affect those brain areas controlling emotion, which diminishes the effects of a painful stimulus. Medications that fall within this class include hydrocodone (e.g., Vicodin), oxycodone (e.g., OxyContin, Percocet), morphine (e.g., Kadian, Avinza), codeine, and related drugs. Hydrocodone products are the most commonly prescribed for a variety of painful conditions, including dental and injury-related pain. Morphine is often used before and after surgical procedures to alleviate severe pain. Codeine, on the other hand, is often prescribed for mild pain.

Symptoms of opioid abuse can be categorized by physical state.

Opioid abuse and its effects to the brain reward system-Intoxication state

Patients with opioid use disorders frequently relapse and present with intoxication. Symptoms vary according to level of intoxication. For mild to moderate intoxication, individuals may present with drowsiness, pupillary constriction, and slurred speech. For severe overdose, patients may experience respiratory depression, stupor, and coma. A severe overdose may be fatal.

Opioid abuse and its effects to the brain reward system-Withdrawal state

Symptoms of withdrawal include the following:

Autonomic symptoms – diarrhea, rhinorrhea, diaphoresis, lacrimation, shivering, nausea, emesis, piloerection
Central nervous system arousal – sleeplessness, restlessness, tremors
Pain – abdominal cramping, bone pains, and diffuse muscle aching
Craving – for the medication

Opioid abuse and its effects to the brain reward system-How does the reward center in the brain work?

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