Understanding How Drugs Can Affect How the Brain Functions

Drugs Can Affect How the Brain Functions

Knowing how drugs can affect brain functions is an important step in recognizing the dangers that drug use can cause. People who are exposed to such substances are not safe from the risks they pose to the human body – from harming the unborn in pregnant women, appetite and weight loss, and even breast development in men.

In extreme cases, these substances can lead to severing one’s life. It gets worse. These destructive effects are not limited to the human body. They can seep through the very social fabric of any community. 

The United Nations Office on Drugs and Crime deems substance abuse as a threat to development and society. It robs every individual of their capacity to think right, behave correctly, and serve productively in the societies they belong to.

While illicit drugs can leave adverse dents on the human body and in society, this article aims to help you understand the threats they pose on one of the most important parts of the human body – the brain. Let’s take a look at how drugs can affect brain functions. 

How does the brain work its magic?

Before we delve into how drugs affect the brain, let’s take a quick review of our past biology classes. It is important to learn how the brain works in order to understand how drugs disrupt its normal processes. 

In movement and speech

Known to be the most complex part of the human body, the brain contains billions of nerve fibres (called the white matter) and approximately 86 billion nerve cells (known as the gray matter). It is found in the central nervous system together with the spinal cord. 

There are three main parts of the brain – the cerebrum, cerebellum, and the brain stem. The cerebrum is the biggest part of the human brain. Its primary function is processing information and voluntary actions. 

This part of the brain is further divided into two parts – the left and the right hemispheres. Connected by a collection of brain fibres known as the corpus callosum, each hemisphere is responsible for the actions of the side of the body opposite to it – the left controls the right and the right controls the left. 

The former hemisphere of the cerebrum controls your arithmetic, comprehension, writing, and speech. The latter hemisphere, on the other hand, is in charge of your musical abilities, spatial capacities, artistic skills, and creativity. 

It doesn’t come as a joke that the brain is the most complex part of the human body because the two hemispheres can be further divided into more parts called lobes. There are four kinds of lobes – frontal, temporal, occipital, and parietal – each of which has its own special functions. These can be found below:

Frontal lobe

  • Cognition
  • Recent memory
  • Planning of locomotion
  • Some aspects of emotion

Temporal lobe

  • Hearing
  • Advanced visual processing

Occipital lobe

  • Vision

Parietal lobe

  • Senses of touch, temperature, and pain
  • Spatial projection

Found behind the top part of the brainstem is the cerebellum. Taking only about ten percent of the total weight of the human brain, the cerebellum is in charge of the coordination of fine muscle movement as well as balance. 

This part of the brain is not to be messed with. That’s why it’s important to understand how drugs can affect brain functions. Despite its minute size, the cerebellum contains approximately half of the brain’s neurons. Neurons are brain cells that specialize in sending signals to the brain. 

The cerebellum works its magic through the information received from other sensory systems of the body, in collaboration with other parts of the human brain. As soon as these pieces of information get processed by the cerebellum, it then regulates locomotion. 

Not only is this part of the brain responsible for movement regulation but as well as movement coordination. The ways you stand, sit, walk, dance, jump, swim, and even speak are all attributed to that small portion at the back of the brain. So, if you find yourself being able to do these and more, thank the cerebellum for it. 

Just like the cerebrum, the cerebellum is also divided into two hemispheres – the right and the left hemispheres. Both of these hemispheres work in tandem with the ones found in the cerebrum. 

The right cerebellar hemisphere functions jointly with its left counterpart in the cerebrum, while the left cerebellar hemisphere works in conjunction with the right side of the cerebrum. Altogether, they regulate and control the movements of the human body. 

Extra care for the cerebellum is needed. Damages to this part of the brain may cause loss of balance, tremors, and slower movements. In extreme cases, this can even cause intellectual incapacity or partial or total paralysis of the body.

The last major part of the human brain is the brainstem. This acts as a bridge between the spinal cord and the brain. It is the stem-like portion of the brain responsible for regulating the flow of signals from the brain to the other parts of the human body, and vice versa. 

Apart from this, the brainstem is also in charge of some vital bodily functions such as swallowing, blood pressure, respiration, heart rate among others. Just like the other two major parts of the brain, the brain stem also has smaller components – the midbrain, pons, and medulla oblongata

The midbrain is responsible for auditory and visual processing. The pons is in charge of sleep and awakening, and the medulla oblongata helps regulate vital functions such as breathing and blood circulation.

In hormonal secretions

The nervous system, through the human brain also functions in tandem with the endocrine system – the system in the body that takes control of the secretion of hormones through the bloodstream meant for the functioning and the growth of the human body.  

Hormones are chemicals that circulate the body. They are the reason behind our mood swings, our fight-or-flight responses, and our physical appearances. Below is a list of some of the body’s important hormones and what they are useful for.

  • Serotonin – the feel-good hormone responsible for mood regulation, memory, sleep, and learning
  • Oxytocin – the hormone in charge of sexual arousal, trust, and mother-infant bonding
  • Growth hormone – responsible for growth and development
  • Calcitonin – the hormones associated with the regulation of calcium and phosphate levels in the body
  • Cortisol – the hormone responsible for immunity and metabolism
  • Testosterone – the hormone that takes charge of the development of the male characteristics
  • Progesterone – the hormone involved in the development of female characteristics, especially in menstruation and pregnancy
  • Melatonin – the hormone responsible for sleep cycles
  • Adrenaline – the hormone that triggers the one’s fight or flight response in situations that involve stress
  • Insulin – the hormone that controls how carbohydrates are being utilized in the human body

Related article: What do Do if Your Child is Using Drugs?

Illicit Drugs: Their Kinds and Components

Illegal drugs come in many shapes and sizes in as much as they bring a whole spectrum of adverse effects on the human body. There are drugs that cause nosebleeds, serious tremors, stomach pain, or nausea. Let’s try to understand how drugs can affect brain functions. 

On the more extreme side of the spectrum, drugs can also lead to hepatitis, heart attack, unwanted abortions for pregnant women, and even death. This juncture of the article aims to discuss the most common kinds of illegal drugs and what they have that give them their addictive factor.


China White, Smack, Brown Sugar, call it what you want. This drug comes from the opium poppy flower. Quickly and directly absorbed by the brain, this drug has proven to be one of the most addictive substances out there.  It is an example of how drugs can affect brain functions.

Just like any other drug that gives one a high-in-the-sky kind of sensation, heroin also has dangerous effects when taken in excess. Some of these effects include collapsed veins, kidney disease, and skin infections.


Perhaps the most common kind of illegal drug, marijuana comes in various names – weed, pot, smoke, boom, trees, blunt, dope, you name it. Marijuana contains THC, or tetrahydrocannabinol, a crystalline substance that acts as its main ingredient. THC is what gives its smokers it’s mile-high feeling. 

Despite being known for its potential contribution to the medical field, marijuana still holds grave effects when taken excessively. Over time, this can lead to disruptions in brain development and a massive drop in one’s intellectual quotient. Severe conditions include schizophrenia, depression, heart attacks, and even death.


Taken through injection, snorting, or pill form, ecstasy is a man-made drug and hallucinogen. Also known as Molly, this type of illegal drug sends several chemicals in the brain (e.g. dopamine, serotonin, oxytocin) resulting in mood altercations and immediate energy boost. 

However, this drug does not stay true to its promise for very long. Users of ecstasy usually feel nausea, anxiety, and sleep problems when the happy time wears off. When taken in prolonged excess, this can also cause blurred vision and increased heart rate and blood pressure – not so very ecstatic conditions.


More commonly known as meth, this variant of illegal drugs are procured from a mix of pseudoephedrine – a common ingredient in cold medications – and other toxic chemicals. Meth, or ice, chalk, crank, or crystal meth, gives its user an immediate high that fades quickly. 

As a result, its users usually take it in consecutive repeats making it one of the most addictive illicit substances there is. Meth gives off different results from other illegal drugs. Some of these include weight loss, skin sores, and severe dental issues and even increased chances of getting HIV. The severe ones are those that meth shares with other illicit drugs. These are anxiety, confusion, insomnia, and hallucinations.


This medication is an herb in the mint family that is local to parts of Mexico. Also called as Sage of the Seers, Sally-D, Magic Mint, and Maria Pastora, the salvia can be used through smoking or chewing its leaves. 

The drug makes extreme, however fleeting impacts, which begin within five to ten minutes and last around 30 minutes. The psychedelic impacts incorporate changes in vision, disposition, feelings, and body sensations.

How do illegal drugs affect the brain?

Understanding how drugs can affect brain functions is important. It has already been established that illegal drugs bring adverse effects on the human body, especially the brain. When somebody puts these synthetic substances into their body, either by smoking, infusing, breathing in, or eating them, they tap into the brain’s usual framework and mess with the way nerve cells normally send, receive, and process data.

Various illicit drugs, on account of their concoction structures, work in various ways. A few drugs, similar to heroin, have compound structures that copy a synapse that normally happens in our bodies. Indeed, these medications can trick our receptors, lock onto them, and actuate the nerve cells.

Be that as it may, they don’t work a similar path as a characteristic synapse, and the neurons end up sending irregular messages through the mind, which can cause issues both for our cerebrums and our bodies. 

Other drugs such as cocaine and methamphetamine cause nerve cells to discharge an excess of dopamine, a characteristic synapse, or avert the typical reusing of dopamine. This prompts misrepresented messages in the mind, causing issues with correspondence channels. It resembles the distinction between somebody murmuring in your ear versus somebody yelling in a mouthpiece.

How does one become high?

It was assumed by researchers that the surge of dopamine, known as the reward chemical of the body, alone caused the sentiment of elation during drug use. Yet, they presently realized it is more entangled than that. Let’s take a closer look at how drugs can affect brain functions. 

Numerous medications—nicotine, cocaine, marijuana, and others—influence the cerebrum’s reward circuit, which is a component of the limbic system. Ordinarily, the reward circuit reacts to sound, pleasurable exercises by discharging the dopamine, which shows different pieces of the cerebrum to rehash those exercises. 

Medications assume responsibility for this framework, discharging a lot of dopamine—first in light of the medication yet later basically because of different signs related to the medication—like being with individuals you used these drugs with, or being in spots where you utilized them. 

The mind recollects this inclination and conveys a serious inspiration to look for and utilize the drug once more. Hence, dopamine does not cause the surge of sentiments; rather it fortifies the longing to utilize drugs.

Constant cravings

Our brains are conditioned to ensure we will rehash survival exercises, such as eating, by associating those exercises with a sense of bliss. At whatever point this reward circuit’s switch is toggled, the mind takes note that something significant is going on that should be recollected and instructs us to do it over and over, without even questioning it. Since these drugs come in and seize a similar circuit, individuals figure out how to utilize drugs similarly. 

After constant repetitions of drug use, the mind begins to conform to the floods of dopamine. Neurons may start to lessen the number of dopamine receptors or just make less dopamine. The outcome is less dopamine motioning in the mind—like cutting back the volume on the dopamine signal. Since certain medications are harmful, a few neurons may die. 

Therefore, the capacity to feel joy is decreased. The individual feels numb, dormant, and depressed, and is unfit to appreciate things that once brought delight. Dopamine urges the mind to rehash the pleasurable movement of medication-taking to have that feeling once more. This leads to the user resorting to drug use as a way of wanting to feel normal again.

Effects in the Long Haul

Every illicit drug rewires the brain to deliver its euphoric impacts. Be that as it may, some can likewise cause harm because of seizures, stroke, and direct poisonous impacts on the brain. Drug use can likewise prompt habit, a psychological issue that happens when rehashed drug use prompts changes in the capacity of numerous brain circuits that control delights, stress, basic leadership, motivation control, learning and memory, and different capacities. 

These progressions make it harder for those with a dependence on experiencing joy because of characteristic prizes, for example, sustenance, sex, or positive social collaborations—or to deal with their pressure, control their driving forces, and settle on the solid decision to stop craving for drugs.

Addiction is regularly entwined with other psychological wellness issues, yet this relationship doesn’t generally have a reasonable directionality. For instance, individuals who experience the ill effects of mood issues are twice as prone to experience the ill effects of a substance use issue, and individuals who experience these kinds of issues are roughly twice as liable to battle with a state of mind of uneasiness. It isn’t clear which issue is causing the other, yet the relationship is solid nonetheless.

The mental dilemma related to substance misuse can extend from mellow to genuine. At any dimension of seriousness, this trouble can have a significantly negative effect on the life of an addicted person. Among the most widely recognized long term emotional well-being issues related to drug misuse and dependence are: 


There is an unmistakable relationship between substance misuse and sorrow, just as other mood disorders. This relationship could be credited to previous melancholy that prompted medication misuse or it may be the case that substance use caused changes in the mind that expanded burdensome symptoms. 

Some individuals use medications to self-sedate side effects of gloom, however, this just lightens the indications while the client is high. It might even aggravate despondency manifestations when the client is working through withdrawal. Numerous medications have a withdrawal disorder that incorporates sorrow or other temperament aggravations, which can entangle recuperation. 


Drug addiction is likewise connected with nervousness and frenzy disorders. Again, the reason is hard to recognize and can be distinctive among people. For one individual, they could build up a manifestation of maltreatment in the wake of utilizing drugs to adapt to their side effects. 

Someone else could have a long-standing example of drug misuse and thusly create nervousness issues. Numerous substances, especially stimulants like cocaine, can cause uneasiness as a portion of ward side effects. Other drugs can result in severe anxiety as a feature of their withdrawal syndromes.


A few drugs, similar to cocaine, can cause sentiments of distrustfulness that may enhance with long term misuse. Apart from this, individuals battling with substance abuse may feel that they have to cover up or lie about their addiction, demonstrating a fear of being caught in the act. The way that numerous substances of maltreatment are unlawful can likewise add to mounting sentiments of suspicion among long haul drug addicts.

With that said, how do we get rid of it?

So much about illegal drugs and their adverse effects on the human brain have been laid out here – from the major components of the brain and their uses down to the mental consequences that are dealt with by drug addiction. 

But still, one question remains hanging – how do we get rid of it? Now that we understand how drugs can affect brain functions, the smartest phase of action that can be carried out is to not even try taking in any illegal drugs at all – not even a whiff, not even a taste. As what the cliché statement says, prevention is better than cure. Choosing to avert illegal substances such as these is the only sure way to never get caught in a dangerous addiction. 

However, not everyone is as lucky to jump over the rabbit hole. There are those, for numerous reasons, have found themselves entangled in the social ill that is drug abuse and addiction. And when they try to cut the perilous habit, they succeed in climbing up the hole. They take a few more steps up but only to find themselves rolling down the pit again. 

Putting an end to this addiction is no bed of roses. Whenever this mishap takes place, it is always best to seek professional help. Learn the tips to get your way out of drug addiction through people who specialize in these situations. 

And above all, surround yourself with people who truly care for your well-being. Seek out the people who are willing to see you out of the rabbit hole and finally into the light. After all, no one’s ever escaped from drug addiction alone. Call Inspire Change Drug Rehab in Vancouver for addiction treatment programs.

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