5 substances that cause the strongest relationship, and their impact on our brains

This ranking is compiledDevelopment of a rational scale to assess the harm of drugs of potential misuse British psychiatrist, Professor of Neuropsychopharmacology David Nutt and his research group.

1. Heroin

Heroin - opioid drugs, which develops a strong physical and mental in the use addiction. This is due to the fact that rapidly penetrates in an injection substance in the brain, it is easy to overcome the blood-brain barrier between the blood and the central nervous system. In the brain, it causes increased production of dopamine. Experiments in animal models have shownElevations of nucleus accumbens dopamine and DOPAC levels during intravenous heroin self-administration increased levels of the hormone of pleasure up to 200%.

Heroin mimics a naturally occurring substance in the brain, which have been created by nature to control pain and increase pleasure.

An additional mechanism of addiction is the increased production of the neurotransmitter glutamate excitation. Combined with severe withdrawal symptoms - pain, anxiety, convulsions, insomnia - this leads to a strong dependence. Breaking begins after 4-24 hours after the last dose, and the addict in dire need of another portion of drug. In addition, the body quickly develops a tolerance to heroin - a person each time is required more and more of the dose.

Heroin addicts often die from heart attacks, strokes, because the drug affects the state of the cardiovascular system. Another cause of death - exhaustion, which results in a constant stimulation of the central nervous system. Experts assigned to this drug three points out of three possible in the degree of dependence.

2. Cocaine

Cocaine - an alkaloid found in plants of the genus erythroxylum. In nature, it acts as an insecticide and protects the leaves of bushes from being eaten by insects. Cocaine has a powerful stimulating effect on the central nervous system, it causes a feeling of euphoria.

Usually in the brain's reward system works according to certain rules. Neurotransmitter - in this case dopamine - enters the space between neurons, called synapses. Specialized receptors transmit the signal for response to its appearance, then removed neurotransmitter from the synapse, to terminate the exposure.

Cocaine blocks the reuptake of dopamine system, forcing it to work again and again, resulting in an explosion of pleasure hurricane.

However cocaine euphoria lasts forever, and after drug action occurs depressed state phase. Among other side effects - fatigue, anxiety, insomnia.

Cocaine is dangerous for the cardiovascular system. He is the most powerful spasms that can lead to hemorrhage into the brain, disrupt the heart or other organs. Another negative effect - a state of acute psychosis in which people little control of himself. In addition, there is a myth that cocaine is not addictive, but it is notThe Neurobiology of Cocaine Addiction.

3. Nicotine

Nicotine, like cocaine - alkaloid in nature performs the functions of controlling insects. This is the main component of tobacco that causes addiction. Nicotine is rapidly absorbed by the lungs and is transported to the brain. It increases the activity of nicotinic acetylcholine receptors, which leads to the release of adrenaline. This temporarily stimulates the various systems of the body, and the person feels more energetic and active. And the release of dopamine accompanies smoking sensation of pleasure.

Nicotine is toxic, prolonged use contributes to the development of cancer, ischemia, angina, and so on. WHO claimsBeneficial effects of nicotine and cigarette smoking: the real, the possible and the spuriousThat 50% of smokers die of causes related to smoking habit.

4. barbiturates

Calming and sleeping medicines based on barbituric acid have a depressing effect on the central nervous system. Depending on the dosage of the drug can have easy relaxing effect or lead to a coma.

Barbiturates stimulate inhibitory neurotransmitter receptors - gamma-aminobutyric acid, whereby the transmission of impulses in the central nervous system slows down. This leads to muscle relaxation, sedation, eliminating anxiety. Depending on the drug problem long suppressed, but later recognized and refusedDeadly drugs and organized crime. How Big Pharma corrupted health from barbiturates to benzodiazepines.

In this case, if the cocaine and heroin are illegal, these drugs over time were relatively available, which increases their danger.

5. Alcohol

Absolutely legal in most countries of spirits calledDevelopment of a rational scale to assess the harm of drugs of potential misuse the most dangerous drug in the world. they are addictive and cause fast enough. Animal studies have shown that alcohol increasesOral alcohol self-administration stimulates dopamine release in the rat nucleus accumbens: genetic and motivational determinants the level of dopamine in the 40-360%.

Alcohol increases the effect of the action of gamma-aminobutyric acid (GABA) - primary braking mediator nervous system. Therefore, movement and speech drunk people slow down, and the dose of alcohol relaxes. GABA is gradually adapting to the changes, reducing the activity of the receptors, making the brain dependent on alcohol.

If a person stops drinking alcohol, decreased GABA receptor activity leads to a weakening of nerve braking function, and the brain becomes more excitable.

At the same time, ethanol reduces the ability of other neurotransmitters - glutamate - impact on NMDA-receptors. In the long use of alcohol increases the number of these receptors. The brain becomes less sensitive to alcohol, and more sensitive to glutamate. This enhances the excitability, leading to withdrawal symptoms: convulsions, anxiety.

Another reasonIncreased brain uptake and oxidation of acetate in heavy drinkers of dependence - the ability to quickly produce energy for brain power. This requires acetate - intermediate product of alcohol metabolism. The brain sits on a simple energy source. In the body of the person to drink alcohol regularly replaces the familiar energy source - glucose.

According toAlcohol consumption WHO, each year 3.3 million people die in the world due to the use of alcohol. The statistics include the accompanying alcoholism disease and injury.

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Dr. Nutt himself pointed out that the legal status of the drug is not necessarily associated with dependence or harm from it. Tobacco and alcohol occupy high positions in the ranking, but remain legal.

However, the existence of the list does not mean that substances that do not fall into it, do not cause addiction. Therefore, the rating should not be perceived as a tool for drug division by harmful and harmless. The use of any psychoactive substances has consequences.