Smoking Effects On The Brain

Studies examining the connection between nicotine addiction and brain health have been underway for many years. Scientists are looking into the connections between smoking, brain damage, neurodegenerative disease and the rate of growth in smokers’ brain cells.

Research: Smoking and its Effects on the Brain

Studies examining smoking and its effects on the brain fall into two main categories. The first category explores the connection between nicotine and addiction: What goes on in the brain of an addicted person and how you may counter nicotine’s effects if you’re interested in quitting. The second area of study explores the potential effects of long-term smoking on brain cells, cognitive function and mental health.

Smoking, Brain Damage and Nicotine Addiction

Many smokers know that smoking is destructive to their bodies, but this awareness is rarely enough to help smokers defeat their addiction to nicotine.

A key chemical involved in the addictive effect of nicotine (and many other addictive drugs) is a neurotransmitter called dopamine. Dopamine activates reward pathways in the brain, and nicotine–especially when inhaled through a cigarette–sends a flood of dopamine to the brain circuitry that regulates pleasure.

The effect peaks within ten seconds of inhaling, but dissipates quickly. This increases the desire to repeat the reward by smoking, which in time can worsen smoking effects on the brain. If you try to quit once you’re addicted, withdrawal symptoms often occur, which may lead you back to smoking. Effects on the brain induced by withdrawal may include anxiety, difficulty paying attention, sleep disturbances and irritability.

Smoking, Brain Damage and Brain Cells

The connection between smoking and mental illness is also being researched. A study published in the Journal of the American Medical Association reported that 41 percent of respondents who had suffered from a mental illness within the past month were smokers. In contrast, only 22.5 percent of respondents with no history of mental illness were smokers. Indeed, the researchers concluded that those with mental health issues were twice as likely to be smokers (Lasser, Wesley, Woolhandler, et al., 2000).

If you’re interested in protecting your brain cells and maintaining optimal brain function, however, your first and most urgent concern should be the carbon monoxide content in cigarette smoke. Hemoglobin is the element of the blood responsible for carrying oxygen to body tissues–including brain cells–and carbon monoxide inhibits hemoglobin’s ability to do its job.

A lack of oxygen compromises the health and functionality of all our organs and body systems–our brains, especially. Without oxygen, our memory and analytical ability is impaired. Over time, oxygen-deprived brain cells eventually die.

Oxygen deprivation may cause other types of damage, including polycythemia, a condition that causes an increased number of red blood cells. This causes blood to clot more easily, which may increase the risk of heart attack or brain damage caused by stroke.


Lasser K., Wesley B. J., Woolhandler S., Himmelstein, D. U., McCormick, D. & Bor, D. H. “Smoking and mental illness: A population-based prevalence study.” JAMA. 2000; 284: 2606-2610.

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