Substance effects on the brain

With just a quick search on the Internet for common addictions, it’s clear that there are addictions that are more common than others. The list of the top 5 addictions in the world are not necessarily the same as the top five worst addictions. Addictions are variable in how intense and quickly they take over. The hard addictions we are talking about in this list will usually require professional treatment for a successful recovery. Trying to manage the withdrawal symptoms of some of these addictions can be lethal.

1. Alcohol is the Number 1 Addiction in the United States

An estimated 30 percent of Americans have suffered from an alcohol use disorder in the past. That’s close to 100 million people. In 2010, nearly 18 million Americans were classified as being addicted to alcohol. Alcohol is the number one choice when it comes to substance abuse and addiction. Not that anyone would choose addiction, but when millions of people are abusing it, it becomes a common addiction. Nearly 10 people will die every hour due to alcohol-related causes.

“Alcoholism is one of the most common addictions affecting Americans. It's also an addiction that goes untreated in many cases because of the legality of the substance. However, the recorded rates of alcoholism are decreasing (18.1 million people in 2002 to 16.7 million in 2011), but the addiction is still a cause for concern."- Addiction Center

Most people may think that alcohol isn’t a dangerous drug, given its legality in the US. But, given its level of addiction and it’s withdrawal effects, it’s safe to say that alcohol is one of the worst addictions to kick.

Why is alcohol so addictive? Alcohol alters the brain, it is the ethanol in alcohol that is to blame. When alcohol becomes a chronic dependence, it will change the way the brain functions, it will require the substance to feel normal.

Alcohol affects certain neurotransmitters that create the addiction. They include:


This is the main neurotransmitter that is inhibitory and limits any excitability in the brain making a person feel relaxed. This neurotransmitter is to blame for the problems with motor skills and memory when we drink in excess. This occurs every time a person drinks, so when someone abuses alcohol for an extended period of time the brain adapts to the increased inhibition. The chemical reaction that occurs in the brain causes a tolerance to alcohol, which means a person will need to use it more to achieve the same effect.


This neurotransmitter is affected by alcohol also. Dopamine sits within the reward system portion of the brain. It is released when we experience pleasure, which includes alcohol consumption. The initial euphoric effects of alcohol are pleasurable and the brain deems this rewarding and reinforces the process by releasing dopamine.

Alcohol will interfere with how the brain uses dopamine and it starts to inhibit the ability to feel pleasure. When alcohol is chronically abused, it decreases the natural ability to produce dopamine, which results in the user only feeling happy when they drink. The withdrawal symptoms of drinking are challenging and can be deadly. Due to the change in brain chemistry, when you stop drinking, you may experience:

  • Hallucinations.
  • Tremors.
  • Convulsions.
  • Delirium tremens.
  • Shaking and shivering.
  • Irregular heartbeat.
  • Sweating.
  • High temperature.

There are also external reasons people can easily become addicted to alcohol. It may be that alcoholism runs in the family, which makes a person more susceptible. Societal pressure may also play a part. Stress, mental health issues, peer pressure, and of course the accessibility are all reasons alcohol is the most common addiction.

2. Heroin May Be the Most Addictive Drug in the World

According to a professional panel, heroin is at least among the top five most addictive drugs in the world. It may not be the worst addiction to kick, but it is up there.

“Heroin hits the addiction trifecta: It causes the brain’s dopamine levels to increase by up to 200 percent, it causes brutal withdrawal symptoms and has a cheap street value.”- Samuel Osborne, The Independent

As an opioid, heroin blocks pain and gives a feeling of euphoria. This is because the drug binds to opioid receptor cells. When heroin is used, the body converts it into morphine which gives a person a rush of pleasure and extreme relaxation. This is what causes people to use heroin over and over again. Once a person is chronically abusing heroin, the brain begins to adjust. This is known as tolerance where the brain gets accustomed to the higher level of opioids.

The user will then need more heroin to get the same high as before. The signs of dependence avoiding a sick feeling, restlessness, and shakiness. Stopping too quickly could include pain in the bones and muscles. The person may also experience:

  • Cold sweats
  • Tremors
  • Nausea
  • Diarrhea
  • Runny nose
  • Goosebumps
  • Anxiety
  • Agitation

Why does this occur? The brain is trying to find a place of balance, attempting to restore normal levels of opioids. This is where the intense cravings for heroin will come from. Dependence quickly turns to addiction. The person will then use heroin uncontrollably, despite the loss they will face. Severe cravings will occur when there is no heroin in the system. Heroin is a powerful drug that interferes with how your brain experiences pain or pleasure.

Not only is heroin one of the most addictive drugs in the world but it is also one of the most dangerous drugs in the world. Taking just five times a normal dose can become lethal, and heroin has a wide range of devastating physical and psychological side effects for users.

3. Cocaine is Still One of the Worst Addictions in America

There is no doubt about it: cocaine is not only one of the hardest types of addictions to quit, but also one of the worst represented in the United States.

While it may not be as popular as it was in the 1980s, around 1.5 million people continue to suffer from cocaine addiction in the US. Because cocaine boosts positive mood and energy, people using it recreationally or at work can easily become addicted to its effects. It is usually taken socially, which can make kicking the habit even harder.

Traditionally, our brain cells cycle will reuse hormones such as serotonin and dopamine. These neurotransmitters determine how we experience desire, motivations, pleasure, and reward. Brain cells send out signals usually and they’re taken up by receptors on that cell. Cocaine shuts down this normal process of the brain. It creates pleasure, feelings of desire, and behavior reinforcement. Dopamine begins to build up. Cocaine also alters serotonin levels which is what balances our moods.

Cocaine prevents dopamine from being reabsorbed, causing it to linger in the brain. This creates an intense feeling of euphoria. When the cocaine quickly wears off and the dopamine is absorbed, the brain isn’t capable of creating its own dopamine. This creates depression, exhaustion, and mood swings. If the user has more access to cocaine, they are likely to use it.

This is known as reinforcement.

It’s been found that cocaine addiction changes the genetics of a person which is what can lead to physical addiction. Cocaine activates genes that cause a reinforcement for taking the drug. There are also withdrawal symptoms that mentally and emotionally take their toll. The body will crave the drug to regulate one’s mood.

Cocaine starts to affect the brain in just a few seconds but the high is short. This creates a quick dependence on the drug. When a person injects or smokes it, cocaine travels quickly to the bloodstream and the brain. It will be a stronger but more short-lived high. Snorting cocaine is still short-lived but lasts a little bit longer.

4. Dependence on Prescription Painkillers is One of the Most Common Addictions in America

There is no question about it: Americans are becoming increasingly addicted to prescription drugs. Prescription painkillers are included in this list of the top 5 worst drug addictions for several different reasons:

  • There is a growing social acceptability for using (and even abusing) prescription painkillers.
  • The vast majority of prescription opioids can be used to get high.
  • Drugs like OxyContin and Vicodin can both create a sense of wellbeing and cause withdrawal symptoms – two hallmarks of drug abuse.
  • Opioid painkiller use has risen by 300%.

The increase of opioid prescriptions written is believed to play a major factor when it comes to addiction to opioids. Prescription pain relievers became the gateway drug to heroin which has caused a 45% increase in heroin deaths. The likes of Vicodin, Percocet, and codeine have the same effect as heroin. When a prescription is “cut off” from a person, they may turn to the streets to get heroin which is cheaper and easier to obtain.

The same effects that heroin has on the brain and body exist with prescription opioid painkillers. There is an intense high which varies depending on how the drug is taken. Prescription painkillers can be injected and snorted as people may abuse them. Opiates affect the opioid receptors in the brain. This gives them a variety of side effects.

Attaching to the opioid receptor causes the GABA chemical to release which is what controls the release of dopamine. The high is caused by the flooding of dopamine to the brain, just like heroin. Muscles in the body relax.

5. Amphetamine Use is Turning Into One of the Worst Addictions

Amphetamines are a stimulant class of drugs that includes dextroamphetamines, amphetamines, and methamphetamines. When taken, they boost energy, mood, and confidence. They also help to suppress one’s appetite. They are used sparingly as a weight loss tool but the likes of Adderall are being prescribed to those with ADHD liberally.

This has turned into a relatively new form of drug abuse and addiction in the US. While many people seem to think that there are few consequences for abusing amphetamines like Adderall, this could not be further from the case.

With so many people being diagnosed with ADHD, drugs like Adderall are making it onto the streets. The medications that include amphetamines for those with ADHD work differently in the brain than they do of the general population. They are more addictive when abused by someone who doesn’t have the disorder. Due to the ease of being able to obtain these drugs is one of the explanations on why it’s one of the most common addictions in the U.S. today.

Amphetamines are synthetic drugs that are designed to stimulate the central nervous system. This is why people will have increased energy and some of the functions within the body go on supercharge. Their effects are similar to cocaine with a rewarding high. This is what makes them both physiologically and psychologically addictive.

Any kind of amphetamine is addictive but the most potent of the class is methamphetamines. They are the most addictive and not legal. It was developed recently from amphetamines, which were originally available in nasal decongestants. There is a difference between amphetamine and methamphetamine. The drugs are both central nervous stimulants that are similar in effect.

They’re structurally different compounds, however, meth breaks down to form amphetamine when the body metabolizes it. Methamphetamine is a more potent high and also more addictive. While amphetamine is not as addictive as meth, it still has its risks.

Like other types of addictions, they are caused by body or brain dependency. Amphetamines pass through the blood-brain barrier and affect the central nervous system. It changes brain signaling and neurotransmitters are all affected. It affects the brain’s reward circuitry which can cause addiction. The person will feel a heightened sense of mental wellness. They will have more confidence and think more quickly. Many university students will abuse drugs like this so they can focus better and stay up late into the night.

Addiction Never Has to Be the Final Answer

These drugs are highly used and are some of the hardest addictions to kick, but that does not mean that it is impossible to quit. All of the most common addictions discussed in this list can be overcome with proper professional treatment.

Drug and alcohol rehab represent a hope for the future, no matter which of these worst addictions to overcome you are dealing with. You are given the support you need and therapy to help you gain a greater understanding of your addiction. You may choose to go with inpatient treatment or intensive outpatient treatment. Either way, you’ll be given the best chance of full recovery when you get professional addiction help.

It doesn’t matter if you are dealing with one of the hardest prescription drugs to quit or another one of the most addictive drugs we brought up here. Addiction treatment is the answer to getting you free from the negative effects of drugs and alcohol.

If you still have questions about our list of the top 5 hardest addictions to kick, or about our approach to drug and alcohol rehab, do not hesitate to contact us today.

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