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Why Drugs Are Addictive: Revealing The Reasons Behind Addiction

Why Drugs Are Addictive : What Turns a Regular Person into an Addict?

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The drugs that harm your body, your relationships and your community have the highest possibility of addiction and abuse. Why are some drugs so irresistible that even people who use them casually end up addicted? It all comes down to the way drugs affect your brain chemistry. Let’s take a closer look at why drugs are addictive.

Understanding the Brain’s Reward System

Practically all addictive substances act on the natural reward circuitry of the brain, altering the way a person feels, thinks and acts as they become more and more dependent on the drug of their choice. When a person drinks an alcoholic drink, takes painkillers, injects heroin or snorts cocaine, these drugs change the way their brain processes chemicals known as neurotransmitters.

Every drug behaves in a certain way to alter the brain’s response to stimuli. However, the result is that the practice of using the drug is so energising, relaxing or pleasurable that it triggers a person’s reward system and makes them want to keep using it. After little or some time, depending on the substance, a person’s brain becomes accustomed to the response. Therefore, they require more of the drug to reach the same sedating, euphoric or hallucinogenic effects. Once they have reached this stage, they may display addictive behaviours such as:

  • Compulsive drug seeking
  • Continued use of the drug despite the harm it is causing to themselves or their loved ones
  • Stealing, lying or doing other things that hurt a person’s sense of integrity just to get a hold of the drug
  • Engaging in risky behaviour just to use or obtain the drug


Can You Tell if a Person is Addicted or Dependent on Drugs?

In order to understand why drugs are addictive, it is vital to understand the difference between addiction and dependence. Psychological and physical dependence and addiction do not necessarily mean the same thing. Dependence is often defined by characteristics including:

  • Physical dependence on the substance that leads to withdrawal symptoms if the person cannot use the drug
  • A level of tolerance that requires greater quantities of the substance to fulfil a person’s need for the drug
  • Intense cravings for the substance that lead to relapse when a person tries to stop drinking or using
  • The inability to control the amount of the drug, regardless of the intention to stop or control their habit

What Is the Difference Between Addiction and Dependence?

Dependence does not always lead to addiction. However, it can be difficult to differentiate between the two conditions. Additionally, the two terms are often used interchangeably. The World Health Organisation (WHO) characterises both states as involving tolerance, compulsive drug-seeking behaviour and symptoms of withdrawal.

Tolerance describes the reduced reaction to a drug after frequent using, which means that the dosage must be increased to reach the same effects. Similarly, withdrawal refers to the physical and psychological symptoms that occur when a person suddenly stops using or greatly decreases their regular dosage.

Drug addiction is marked by a change in behaviour caused by the biochemical changes in the brain after continued substance abuse. It is beneficial to use both terms independently when a person is dealing with addictive substances that are used for medical reasons or addictive pain medications. Even though many individuals who regularly use opioid pain medication can become dependent or tolerant, that does not necessarily mean that they display addictive behaviour when using or getting the drug.

The characteristics of addiction and dependence can often overlap. Generally speaking, a person can be dependent on a drug without having an addiction, but once an addiction forms, they are often dependent.


Around 18 million individuals in the US abuse alcohol, according to the University of Maryland Medical Centre. Any person with an alcohol abuse problem knows that it can be challenging to stop once you start. Alcohol addicts may expect to have a drink or two after work or at a party, but find themselves drinking throughout the night and into hours of early morning.

What is the reason behind the difficulty some people have when it comes to stopping drinking once they begin, while other people have no problem stopping or even avoiding alcohol entirely? The reason why drugs are addictive, specifically alcohol, in this case, comes down to a mixture of brain chemistry and heredity.

Alcohol is a central nervous system depressant that fuels the release of particular neurotransmitters, specifically endorphins, dopamine, glutamate and GABA. This affects a person’s mood or influences the way their cells convey messages. Even though clinical research has yet to confirm whether alcohol addiction is hereditary, evidence shows that the condition is related to genetics.

If a person feels content, relaxed or giddy after having a few alcoholic beverages, it is likely that their brain cells are responding to the increased chemical production that alters their mood. Similarly, alcohol has an effect on the brain’s frontal lobe, which is accountable for judgment, emotions and impulsive behaviour. Therefore, anyone who has experienced happiness, contentment, anger or altered moods when they have been drinking has experienced the effects that alcohol has on the brain.

If a person has an alcohol problem, they may feel much better when they drink in comparison to when they do not, which causes them to want to keep drinking. On the other hand, a person can also become accustomed to feeling that alcohol causes that they cannot stop without experiencing withdrawal symptoms such as depression, anxiety and tremors. Either way, the reward system of their brain has been rewired to react to alcohol in a way that could lead to addiction.


Methamphetamine, or meth for short, and amphetamine, or speed, are central nervous stimulants that are both highly addictive. When a person takes meth or speed orally, intravenously or intranasally, the substances alter their brain’s response to, or production of, neurotransmitters such as dopamine. They experience an overwhelming sense of euphoria due to the over-production of chemical messengers.

Concurrently, meth and speed stimulate the central nervous system, resulting in feelings of increased mental focus or power. These substances can also encourage weight loss, which makes it appealing to many people. When a person starts using meth or speed, they may find it easier to focus and stay active, such as with school or work. However, with frequent use, their brain adapts to the surge of neurotransmitters that they require higher doses of the drugs to achieve the same high or maintain focus.


Marijuana addiction

Marijuana use is on the rise, especially in the United States. According to the Substance and Mental Health Services Administration (SAMHSA), the increase of cannabis use rose from 6.2% in 2002 to 8.3% (around 22.2 million people) in 2015. Marijuana is becoming more accepted as a drug used to manage pain and stimulate appetite, along with other therapeutic reasons. Along with this acceptance, the recreational use of cannabis is becoming increasingly popular as well.

THC, which is the active ingredient found in cannabis, fuels brain cell receptors that cause feelings such as contentment, relaxation, euphoria and lightheadedness. If a person frequently uses marijuana to unwind after a stressful day or relax after work, they often start to need more of the substance to reach the same high. If they are unable to smoke or ingest marijuana for several days, they may begin to feel agitated, frustrated, depressed and edgy.

The pleasant feelings that are caused by marijuana use can restrain a person’s brain reward system to respond positively to marijuana use and to experience withdrawal symptoms, like anxiety, cravings, depression and stress, when they cannot take the drug.


The energy, self-confidence and euphoria that a person feels after taking cocaine make it one of the most addictive drugs out there. Cocaine was initially used in the medical field as an anaesthetic and numbing agent, with its ability to decrease pain while increasing pleasurable feelings, which are often quite intense. Cocaine utilises its addictive authority on the central nervous system by altering the way the brain processes dopamine. Once dopamine is released, cocaine hinders the brain cells from reprocessing the neurotransmitter, causing a surplus of the pleasurable effects of the chemical.

A person can feel so euphoric after doing cocaine that they lose interest in most of their usual activities and relationships. Even though the effects of cocaine are felt almost instantly, especially if it is smoked or injected as crack, the high from cocaine does not last long. A cocaine high generally lasts no longer than fifteen to thirty minutes. In order to keep their high going, cocaine addicts have to keep taking the drug, which leads to an expensive and harmful habit.

Opioid (Prescription Drugs/Heroin)

Opioids are a class of drugs that originate from morphine, including prescription medications such as Dilaudid, OxyContin and Percocet, as well as illicit drugs such as heroin. Opiates like heroin and morphine come from the opium poppy, while drugs like hydrocodone and oxycodone are manufactured in a lab. Both synthetic and natural opioids are incredibly powerful, and the potential of becoming addicted to them is very high.

Opioid drugs are highly addictive since they act much like endorphins, our body’s own natural pain relievers. Endorphins latch on to the brain cells opioid receptors, producing sensations of well-being or pain relief. Opioid drugs act in the same way, creating similar feelings with more intensity. Opioids such as heroin can cause an addictive surge of euphoria, particularly if they are injected intravenously.

Once a person becomes dependent on any form of opioids, they will experience severe withdrawal symptoms when they cannot get the drug or if they try to quit. Intense cravings, sweating, shaking, nausea, irritability, agitation, vomiting, and bone and muscle pain are some of the most common withdrawal symptoms that make it difficult to recover from opioid addiction.


Meth is occasionally used for medical purposes but only in tiny doses because of its addictive properties. Meth can cause a high that lasts for several hours, or even days, and has the ability to make people feel as though they can do anything. It also gives people more energy, increases sex drive and enhances mood and body movement. Additionally, meth is much cheaper and easier to get a hold of than substances such as cocaine. Meth is so potent that it can lead to addiction after just one use.

Meth affects the brain by discharging extreme amounts of dopamine, which causes a pleasurable rush that results in a high. Once the high wears off, the brain keeps craving the drug to reach that feeling again and again. This occurs because meth disturbs the brain’s reward centre. Regular meth use causes the brain to associate pleasure with meth use, which forces meth users to keep seeking the substance in order to meet their body’s cravings.

Ultimately, the brain stops producing dopamine since it is getting it in excess from the meth.The person using meth can no longer experience any pleasure without using the drug. They must also use meth in increasing quantities to feel happy. After time, using meth causes reduced serotonin levels, a neurotransmitter like dopamine. This can result in Parkinson’s or Alzheimer’s disease.

Seratonin functions in the brain as a messenger of feelings of content and well-being. It also helps with other important functions such as sleeping and eating. When drugs interact with serotonin, it can affect an individual’s sense of well-being and happiness, causing anxiety, depression and other mental health issues.


Ecstasy, or MDMA, is psychologically addictive instead of physically addictive. It causes intensely pleasurable sensations, or an ecstasy high, by releasing all of the serotonin in a person’s brain in one go. Because ecstasy depletes a person’s serotonin level, the majority of people experience a comedown for a day or so after ecstasy use, which causes them to feel anxious, depressed and generally down. Additionally, the only way to refill our serotonin level is to wait several weeks for the brain to do it on its own. Users who do not wait until their serotonin level replenishes again find that the substance does not cause the same effects as it did the first time.

Since their serotonin level is already reduced, they cannot reach the same high as when it was normal. Therefore, they have to take a higher dose to achieve the same effects. If a person keeps doing this, at some point they will have to take a considerable amount of the drug to just feel normal, which is what results in a psychological ecstasy addiction.

Why Drugs are Addictive in Comparison to Natural Rewards 

When some substances are taken, they can release up to ten times the quantity of dopamine that natural rewards like sex and eating do. In some instances, this happens almost right away, such as when substances are injected or smoked, and the effects continue for a longer period in comparison to those created by natural rewards. The effects on the pleasure circuit of the brain dominate those produced by naturally rewarding behaviours. The effect of the reward has the power to motivate people to continue to take drugs time and time again.

What Treatments are Available for Drug Addiction?

There are numerous treatment options available for individuals struggling with any form of addiction. Many individuals use a combination of various types of treatment. For example, once a person completes inpatient treatment at a drug rehab centre, they may continue with a 12 Step programme. Some of the most common forms of treatment include:

  • Short-term Inpatient Treatment

    Short-term inpatient options at a drug rehab centre are often suitable for individuals who have many responsibilities, who cannot take a long leave of absence from work or school and who prefer a shorter duration, which typically lasts several weeks.

  • Long-term Inpatient Treatment

    Long-term inpatient options at a drug rehab centre are ideal for individuals who have a severe addiction, require around-the-clock supervision and care, and can take an extended leave from work or school. Long-term inpatient treatment typically lasts anywhere from three to six months.

  • Outpatient Treatment

    Outpatient recovery offers different levels of care and intensity. The most common outpatient programmes include weekly or more frequent visits to the outpatient centre and consist of individual and group therapy. Unlike inpatient treatment, the person does not reside at a drug rehab centre.

  • Dual Diagnosis Programmes

    Dual diagnosis, or co-occurring disorder, programmes are designed for individuals suffering from both substance abuse and mental health disorders, such as bipolar disorder or depression. It is recommendable to find a drug rehab centre that specialises in dual diagnosis when seeking treatment.

  • 12 Step Programmes

    12 Step programmes are typically used alongside other forms of treatment, especially at the beginning. Individuals who have completed treatment programmes at a drug addiction rehab centre tend to continue 12 Step programmes to maintain sobriety and avoid relapse.

Why Choose The Dawn Rehab Thailand

The Dawn Medical Rehab and Wellness Centre offers a highly tailored and intensive addiction treatment programme that is customised to suit each individual’s unique requirements. We offer a holistic, humanistic and non-religious approach that is not only effective but also applicable to any individual.

The Dawn’s licensed team of addiction professionals have extensive experience and are qualified to apply various forms of therapies and counselling to help ensure a successful recovery. In addition, our clients are given the essential tools that are required for sober living following treatment. Aftercare support is also available online at no additional cost.

Furthermore, The Dawn has an onsite detox centre and round-the-clock medical support, as well as an impressive 1:1 staff to client ratio.

If you or someone you know is struggling with addiction, now is the time to get treatment at a drug addiction rehab centre. Contact us today to receive a no-obligation assessment to find out how we can help.

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