Nicotine is Harmful for the Developing Brain – Or is it?

Researchers continue to debate nicotine’s impact on the adolescent brain, with new research indicating that pre-existing factors influence addiction susceptibility more than nicotine itself.

Diane Caruana

March 10, 2025

Several studies suggest that nicotine exposure during adolescence may negatively impact brain development. Since the brain continues maturing until the mid-20s, researchers believe that nicotine can interfere with critical processes related to memory, attention, and impulse control. Moreover, research indicates that adolescent nicotine use may alter neural pathways, potentially increasing susceptibility to addiction and cognitive deficits later in life.

Yet, while experts stress the need for further research to fully understand long-term impacts on brain function, a recent study challenges the belief that nicotine directly harms the brain. Published in The Journal of the American Medical Association (JAMA) the current study suggests that brain structure differences linked to nicotine use are actually present before individuals start using it, indicating that nicotine is more of an effect than a cause.

Nicotine as the effect rather than the cause

Researchers analyzed brain scans of nearly 10,000 adolescents aged 9 to 11, following them for three years to examine changes related to substance use. They found that teens who used substances before age 15 had notable differences in brain structure, volume, and thickness compared to non-users. However, these differences often existed before the nicotine use, suggesting that pre-existing genetic, environmental, and neurological factors influence addiction risk.

In line with this, a study titled “Paternal nicotine taking elicits heritable sex-specific phenotypes that are mediated by hippocampal Satb2” determined that nicotine exposure in parents may contribute to addiction-like tendencies in male offspring across generations. Researchers from the University of Pennsylvania School of Nursing (Penn Nursing) identified that these inherited behaviors may include cognitive impairments and anxiety-related traits.

Therefore while many researchers fear that nicotine causes structural brain changes, this study supports the “common liability theory,” which proposes that shared underlying factors—such as genetics or environment—predispose individuals to substance use. This undermines the idea that nicotine alone is responsible for brain alterations.

Debunking Misinformation About Nicotine

Meanwhile numerous studies suggest it may have cognitive and neuroprotective benefits. Research has shown that nicotine can enhance attention, memory, and cognitive processing by stimulating neurotransmitter release, particularly dopamine and acetylcholine, which are crucial for learning and focus. This has led to studies on nicotine’s potential to improve symptoms of attention deficit hyperactivity disorder (ADHD) and cognitive decline in aging populations.

Several studies have explored nicotine’s role in neuroprotection. Research suggests that nicotine may help protect against neurodegenerative diseases like Parkinson’s and Alzheimer’s by reducing inflammation, promoting neuronal survival, and enhancing synaptic plasticity. Epidemiological studies have indicated that smokers have a lower incidence of Parkinson’s disease, leading scientists to investigate nicotine as a possible treatment.

And while concerns have been raised about nicotine’s effect on mood regulation, with some research linking adolescent exposure to increased risks of anxiety and depression, nicotine has also been studied for its potential mood-enhancing effects. Some research suggests it may help alleviate symptoms of depression and anxiety by modulating neurotransmitters like serotonin and norepinephrine. Additionally, studies on schizophrenia patients have found that nicotine can improve cognitive deficits and sensory processing issues commonly associated with the disorder.

Experts argue that anti-nicotine narratives should be revised to reflect scientific evidence rather than assumptions. The findings highlight the need for fact-based public health policies, reinforcing that harm reduction strategies should focus on education and risk management rather than misinformation and fear-based approaches.