A Specialized Scientific Guide: How Do Chemical Substances Reshape the Brain, Turning It from a Vital Organ into a “Hijacked System”?

Beyond the Observable Behavior

Addiction has long been viewed as a weakness of will or a flaw in personality, but recent research in behavioral neuroscience has upended this perspective. We adopt the biomedical model, which sees addiction as a chronic and complex brain disease.

The journey often begins with a voluntary decision (the first use), but with continued use, structural and functional changes occur in the brain that push consumption beyond the bounds of willpower. The addicted brain is not a “bad” brain; rather, it is a brain exposed to toxic substances that has lost its natural balance, making the craving for the substance a physiological necessity, much like water or food for the nervous system.

The Story of the “Hijacked Brain”

Imagine the brain as the most complex computer in the universe, equipped with an internal reward system that releases dopamine (the hormone of happiness and motivation) when engaging in positive activities like success, eating, or exercise.

Drugs don’t enter the brain as mere guests; they act as hackers. They infiltrate the reward system, forcing it to release dopamine at levels up to ten times the natural amount. This chemical explosion creates a euphoric high, followed by a breakdown in the system, where the brain gradually loses its ability to enjoy normal rewards and becomes “hijacked,” craving only the substance.

Biological Analysis – The Mechanism of the “Hijacked Brain”

To understand how addiction occurs, the process can be dissected across three main neural levels:

1. Hijacking the Reward System

The primary driver of addiction is dopamine. Under normal conditions, the brain releases dopamine in response to achievements or pleasurable experiences like tasty food. Addictive substances, however, trigger an enormous surge of dopamine, 2 to 10 times the natural amount.

Technical consequence: The brain is shocked by this flood and defensively reduces the number of dopamine receptors. This marks the start of dependence; the person no longer feels pleasure from natural rewards and needs increasingly larger doses just to feel “normal.”

2. Prefrontal Cortex Paralysis

This area acts as the brain’s “brake,” responsible for logic and impulse control. Addiction weakens neural connections in this region.

Technical consequence: The individual becomes unable to say “no,” even if aware of the harm. Drives in the older limbic system overpower the logic of the prefrontal cortex.

3. Associative Memory

The brain links the substance with places, friends, or even emotional states like sadness.

Technical consequence: Seeing a trigger associated with use prompts anticipatory dopamine release, creating compulsive cravings even before actual consumption.

Two Primary Brain Regions Involved in Addiction

To understand addiction as a disease, its impact on two primary brain regions must be noted:

1. Limbic System: The center of pleasure and survival. Drugs trick this system into believing the substance is essential for survival, just like water or food.

2. Prefrontal Cortex: The center of logic and brakes. Addiction weakens this region, leaving the person unable to say “no” or foresee consequences, like driving a fast car with no brakes.

The 5 Stages of Dependency

Addiction does not happen overnight; it progresses through a downward path called the chemical spiral:

1. Stage of Experimentation

Driven by curiosity or peer pressure. Often, the person believes they are “in control” and will not repeat it.

2. Stage of Social Use

Starting to associate the substance with certain occasions (partying, studying, celebrations). Here, the brain begins to record the “link” between pleasure and the substance.

3. Stage of Preoccupation

The person starts thinking repeatedly about the substance, allocating part of their budget and time to it. Interest in natural hobbies declines.

4. Stage of Loss of Control

Here, use becomes “compulsive.” The person consumes not for pleasure, but to avoid the “pain” of withdrawal. Tolerance appears, requiring higher doses to achieve the same effect.

5. Stage of Full Dependency

Addiction becomes the “center of life.” Complete deterioration occurs in relationships, health, and functioning. The brain is fully reprogrammed to become a chemical “slave” to the substance.

Worksheet (Scientific Reflection)

Exercise: “Changing the Lens”

1. Think of someone you know who is struggling with addiction.

2. Try to imagine them as a person with “brain chemistry damage” rather than as a “bad person.”

3. How does this change your feelings toward them? Do you feel a greater desire to help them medically?

Remember: “We do not punish a diabetic for high blood sugar; we help them control it. Similarly, a person with addiction needs a strict and scientific treatment protocol.”

Prepared by Dr.

Addiction is a “chronic and relapsing brain disease.” Treating it as a disease opens the door to solutions and treatment, while treating it solely as a moral stigma closes doors and drives the victim to further use to escape shame.

References

1. Volkow, N. D., et al. (2016). Neurobiologic Advances from the Brain Disease Model of Addiction. New England Journal of Medicine. (الدراسة الأهم التي رسخت مفهوم مرض الدماغ).

2. National Institute on Drug Abuse (NIDA). (2020). Drugs, Brains, and Behavior: The Science of Addiction.

3. American Psychiatric Association (APA). (2013). Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

4. Koob, G. F., & Le Moal, M. (2001). Drug Addiction, Dysregulation of Reward, and Allostasis. (حول اختلال التوازن الحيوي).

5. World Health Organization (WHO). (2022). Neuroscience of Psychoactive Substance Use and Dependence.