The science behind addiction

The science behind addiction

To avert stress, to socialize, to fit-in or just curious are a few of the excuses we hear people give about why they got on drugs. Regardless of their reasons, the streets are filled with automatons walking already under the influence of some substance, or thinking about their next fix. It has come to the point that we almost forget it is not how a society is supposed to function. Perhaps an overview of what exactly happens to the human body under addiction will throw some light on how unnatural a process it is.

What are Drugs?

The term “drugs” is somehow ambiguous owing to its extensive use to refer to prescribed medications as well as different abused substances. The following definition is to be used in context of our current discussion: Drugs are chemicals that affect the brain by interfering with the way neurons normally communicate. Some drugs can activate neurons because their chemical structure mimics that of a natural neurotransmitter. This similarity in structure “fools” receptors and allows the drugs to attach onto and activate the neurons. However, the drug does not elicit the same response as the natural neurotransmitter it mimics. As a result, abnormal messages are processed and transmitted through the network. Other drugs cause the production of exponentially larger amounts of chemicals or imped their natural removal. This disruption produces a greatly amplified message, ultimately disrupting communication channels. This malfunctioning of the brain is interpreted in various forms via the users altered behavior, emotional instability and physical manifestations like loss of balance and tremor. These effects are shared by the most commonly abused substances such as alcohol, nicotine, marijuana, cocaine, heroin and amphetamines.

What is addiction?

Addiction (medically referred to as substance use disorder) is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences. It is a recognized mental disorder listed in the Diagnostic and Statistical Manual of Mental Disorders.

It is considered a brain disease because drugs change the brain— its structure and how it works. These brain changes can be long-lasting, and can lead to the harmful behaviors seen in people who abuse drugs. The core manifestation of this state is compulsive drug use despite negative outcomes such as medical illness, failures in significant life roles, or the need to engage in criminal activity to obtain drugs.

When scientists began to study addictive behavior in the 1930s, people addicted to drugs were thought to be morally flawed and lacking in willpower. This led to an emphasis on punishment rather than prevention and treatment. Today however, groundbreaking discoveries about the brain have revolutionized our understanding of compulsive drug use, enabling us to respond effectively to the problem.

Neuronal and behavioral changes

Reinforces (rewards and punishments) are among the most powerful to operate on human beings. Punishments serve to avoid certain undesirable consequences, while rewards produce an experience of “feeling good” leading to repetition of the behavior. The reward system of the brain has an immense influence on human behavior – strong enough to initiate learning processes that consolidate the desire and pursuit of the causative factor. The culprit behind addictive drugs is the fact that they can tap into and alter this natural reward response system of the brain and induce similar responses as natural stimuli for rewards (such as food and sexual intercourse). Rewards and addictive drugs alike produce a euphoric feeling  as a result of their ability to increase synaptic dopamine in the nucleus accumbens, the amygdala and the prefrontal cortex- the regions of the brain that regulate movement, emotion, motivation, and feelings of pleasure.

The difference between the natural and drug induced rewarding is the fact that the first kind is important for survival of an organism. On contrary, the latter is not only caused by chemicals that are harmful but it also causes those chemicals to be valued above the ones that are actually important. When drugs of abuse are taken, they can release 2 to 10 times the amount of dopamine as natural rewards, sometimes with immediate responses that can also last much longer. It is only natural for the user to take the drugs more frequently and with increasing amount. It is the reason why scientists say that drug abuse is something we learn to do very, very well.

This effect, compared to the natural reward is like the difference between someone whispering into your ear and someone shouting into a microphone. Just as we turn down the volume on a radio that is too loud, the brain adjusts to the overwhelming surges in dopamine by producing less dopamine or by reducing the number of receptors that can receive signals. First, neurogenesis (production and regeneration of neurons) decreases as a result of repeated exposure to addictive drugs. Then, the user appears to enter a new allostatic state, defined as divergence from normal levels of change which persist in a chronic state. As a result, dopamine’s impact on the reward circuit of the brain of someone who abuses drugs can become abnormally low, and that person’s ability to experience any pleasure is reduced. Therefore, the person is depressed and lifeless, obliged to use the substance to even feel normal. Also, the person will often need to take larger amounts of the drug to produce the familiar dopamine high—an effect known as tolerance.

Positive reinforcement involves an increase over time in the frequency of behaviors that lead to a reward.  However, it might even be proposed that it is a motivational state that goes beyond feelings: it overwhelms the individual in totality, dominating the thoughts, feelings and actions of the individual to the exclusion of all else.   This is the central phenomenology of addiction: a desire that is so strong and all-encompassing that it sweeps all other considerations before it in a myopic and single-minded search for the object of that desire. Even if in some sense there is a choice, it does not seem like it to the addict or to observers, it is more like a compulsion. Basically, the person turns into a zombie whose sole reason for existence is finding more of the numbing stuff, even though addicts report the euphoria is not as intense as it once was. Evidence shows that this behavior is most likely a result of the synaptic changes which have occurred due to repeated drug exposure and it fits the definition of a medical disorder.

Before a person becomes addicted and exhibits drug-seeking behavior, there is a time period in which the neuroplasticity is reversible. Once addicted, though, individuals remain at high risk of relapse even years after they have ceased drug use. As a result, no treatment episode can be considered curative, and for the most seriously addicted individuals, relapses often occur long after any withdrawal symptoms have subsided.

Individual and societal effects

It has been said way too many times; drugs are detrimental for the human body. Every substance of abuse affects health directly or indirectly in ways that are sometimes impossible to foresee. If we were to list all the disorders caused by chemical abuse we would exhaust all the diseases in the books and more. Instead, we shall see the most common disorders caused by the two mostly used drugs: alcohol and tobacco.

In alcoholics, there is a higher risk and increased reports of: strokes, hypertension, cirrhosis, hyperglycemia, brain damage, vitamin B deficiency, ulcers, gastritis, , malnutrition, cancer of the mouth and throat, not to mention increased amount of accidental and self-inflicted injuries, domestic violence and economic troubles  that are common for every kind of addiction.

Smokers have a higher risk for coronary heart disease, stroke, lung cancer COPD (chronic obstructive pulmonary disease), acute myeloid leukemia, cervical cancer, pancreatic cancer, cataracts, diabetes, rheumatoid arthritis and so much more.

There are also numerous social shortcomings associated with addiction and they hit every stratum of society.

Adolescents who abuse drugs often act out, do poorly academically, and drop out of school. They are at risk for unplanned pregnancies, violence, and infectious diseases.

Adults often have problems thinking clearly, remembering, and paying attention. They often develop poor social behaviors as a result of their drug abuse, and their work performance and personal relationships suffer.

Addiction is a mental illness. It distorts the normal functioning of individuals stripping their lives of meaning and longevity. It takes away dreams, destroys careers and breaks families apart; all of it while the user is under the illusion of control. It makes you wonder if it is worth the alleged benefits or the quick “high”.

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