Overview

Smoking is one of the biggest addictions known today, but it is not labelled as such. About 23% of the world smokes and are becoming slaves to nicotine in its myriad versions, like vaping, e-cigarettes, smoking, etc. Despite there being more awareness on nicotine and its harmful effects, it is still concerning that our teenagers and youths are falling prey to these habits.

Tobacco is a life-threatening addiction that, if unchecked, it can cause harm to each and every organ system in the body.

What is nicotine?

Nicotine is the primary product of the tobacco plant, which is a nightshade plant. Its chemical formula is C10H14N2, and it is highly addictive and stimulative. Nicotine crosses the blood brain barrier (BBB) when smoked, inhaled, or absorbed. It mainly acts on the dopamine or the reward pathway, which produces the feeling of pleasure, alertness, and stress relief. This now leads to an increased frequency of intake to get the pleasurable feelings, forming a continuous loop of addiction. Though people are aware of these effects of nicotine, they are too accustomed to getting that feeling and will not quit.

History of tobacco use

In the 15th century, Christopher Columbus introduced tobacco to Europe. Prior to that, tobacco was harvested by the native americans. Jean Nicot, the person who gifted the tobacco leaf to the queen of France, gave tobacco its botanical name Nicotiana tabacum.

In the late 18th century, consumption of tobacco in the form of packaged cigars and cigarettes gained popularity.

Why is nicotine dependence a concern?

Some smokers start smoking from when they are teens. The tobacco lobby portrays smoking as cool to the easily impressionable minds of the youngsters, who are more susceptible to trying it after looking at social media and adverts.

The potential dangers of nicotine usage are as follows:

• Coronary artery disease: cigarette smoke contains more than 4000 carcinogens, which are released during the combustion of tobacco. The particle size of these carcinogens is enough to block the smallest alveoli and can cause inflammation and thrombotic episodes. This can affect not only the smoker but also others who are exposed to secondary smoke
• Cancer: 87% of lung cancer deaths are attributed to smoking. Smoking itself can cause cancer in every organ system. Tobacco contains about 60 known carcinogens which affects the cellular DNA. This further manifests as mutations and affects the cell reproduction, causing tumours
• Chronic obstructive pulmonary disease (COPD): tobacco smoke contains carcinogens whose particle size increases as it is humidified in the body, and settles in the alveoli and bronchioles. Chronic inflammation in these bronchial walls progresses to fibrous depositions, and the alveoli starts losing their elasticity. This leads to COPD in the long term
• Decreased fertility rate
• Low birth weight and preterm infants in smoking mothers

Mechanism of nicotine dependence

Nicotine dependence can be physical and psychological. The ways in which it forms dependence includes:

Tolerance

The initial high triggered by one dosage of nicotine is gradually reduced on consecutive intake. The body releases fewer and fewer amounts of dopamine with each intake. Hence, the person in the habit will need more and more dosage or increased frequency of intake to get the same high. This is termed as tolerance.

Psychological dependence

Nicotine is a coping mechanism for many against stress, anxiety, or social engagement. The peer pressure of looking cool by smoking can also not be ignored. It is usually associated with a certain routine or trigger, and can affect individual behaviour.

Physical dependence

As more and more nicotine is needed to get an adequate dopamine release, the absence of nicotine will throw the body into an unsettled state. This affects the normal physiological processes of the body and can lead to a wide array of withdrawal symptoms.

Effects of quitting

When a person first quits, the level of nicotine in the blood starts falling rapidly. This affects the brain, which is used to a high level of neurotransmitters in the blood, and gaining its initial normal functionality will take time.

Withdrawal starts manifesting in the first 2-12 hours after the last dose of nicotine peaks in the first few days, and then gradually subsides over a few weeks. In some cases, depending upon the degree of nicotine intake, it might even take months to come back to normalcy.

Why do withdrawal symptoms occur?

The understanding of the physiological and psychological changes of the body is essential to know the root cause of the withdrawal symptoms. Nicotine works in two ways: it reinforces the mechanisms of the brain’s reward circuits when the habit is present and reduces the mechanisms of the brain’s aversion circuits during withdrawal.

Altered dopamine levels

Dopamine, also known as the feel-good hormone, is mainly responsible for the feeling of happiness and well-being in an individual. Nicotine intake increases the level of this neurotransmitter in the blood to a great extent. When nicotine intake is stopped, the dopamine levels fall rapidly, leading to mood changes and feelings of irritability, anxiety, and depression. Since the brain needs time to adjust to the new dopamine levels, the mood changes are seen throughout this transition period.

Neurochemical imbalance

Apart from dopamine, nicotine also affects the levels of other neurotransmitters like serotonin, norepinephrine, and acetylcholine. These are responsible for alterations in mood, alertness, and concentration or focus. When nicotine is stopped, there is a temporary fall in the level of these neurotransmitters, causing loss of focus and concentration, mood alterations, restlessness, and fatigue.

Response to stress

It is a paradox that the nicotine which a person uses to reduce stress is the same nicotine which will cause more stress on quitting, due to its rebound symptoms. Nicotine causes the release of cortisol and adrenaline, but the effect of these hormones dull after prolonged nicotine use. The body becomes immune to it. 

Habit breaking or routine breaking

The nicotine user vapes or smokes during certain times of the day, like short breaks or before stressful encounters like meetings or presentations, or at the end of the day to calm the mind. When nicotine intake is stopped, these cycles are disrupted and similar situations trigger a stressful response in the user. Psychological dependence causes a lot of discomfort. 

Physical craving and rebound

Physical cravings arise in response to the absence of the comfort that the body has become used to. This can be intense in the first few days of quitting, and is manifested as headaches, increased appetite, stomach upsets, and disrupted sleep patterns. These are the body’s attempts to return to its normal physiological process.

Common withdrawal symptoms

The most common withdrawal symptoms reported by users in varying degrees of intensity include:

• Disrupted sleep patterns, with insomnia
• Headaches 
• Dizziness
• Depression (mild to clinical)
• Anxiety
• Restlessness
• Stress eating
• Weight gain
• Difficulty in concentrating
• Vivid dreams 

These symptoms can vary in intensity depending on:

• Duration of use
• Frequency of use
• Amount used on each occasion
• Individual body type
• Stress
• Lack or availability of support systems

Summary

The best way to combat nicotine addiction is to avoid nicotine use totally, or if started, to stop it as soon as possible. With vaping gaining popularity amongst teenagers and youths, the ease of access is concerning, given the long-term ill effects of it on the brain and physical development of youngsters.

Quitting smoking can reduce the chances of developing lung cancer by 40% irrespective of the age of the smoker, the intensity, and duration of the habit. The rate of smoking-related diseases can be reduced by 90% by quitting.