Nicotine has a bad reputation. This reputation comes from its association with cigarettes, and the fact that millions of people die every year from the adverse health effects of smoking cigarettes. But cigarettes have been adulterated to be more addictive, and nicotine itself, when separated from cigarettes, is a different story.

Nicotine is a small molecule that fits into brain receptors called “nicotinic receptors.” These receptors are involved in attention, memory, and mood. Because of this, scientists have spent decades testing nicotine patches, gum, and lozenges as possible treatments for brain-related diseases. Although these results are mixed, they provide hope that nicotine may one day be a safe and effective medicine.

Also, nicotine-containing products are FDA-approved medicines for smoking cessation. A patch, gum, and lozenge are available without a prescription whereas a spray and inhaler do require a prescription.

I previously wrote a PT blog about the potential health benefits of nicotine. But after a reader provided me with additional information, I decided to take a deeper look. And here’s what I found.

Nicotine and Depression

Multiple small studies have shown improvement in depression following treatment with nicotine patches. For example, in a 2018 trial, 15 older adults with depression who had never smoked wore nicotine patches (up to 21 mg/day for 12 weeks). Most got much better, and more than half went into remission. A larger 2024 follow-up study of 29 patients found similar results when nicotine patches (up to 21 mg/day) were added to regular antidepressants. Approximagely 76% of patients responded and 59% went into remission. But both studies were “open-label,” meaning a placebo wasn’t used for comparison. But these results showed that improvement with nicotine was more than double the typical placebo rate (placebo response rate 35-40% and remission rate 20-30%).

Not all studies support these findings. An earlier trial found quick improvement also, but the benefits were reported to decrease within days, and the authors warned that nicotine patches “are not recommended” for treating depression. But wait a minute. This study of 12 patients used a slightly lower dose (17.5 mg), and only treated people with patches for 4 days. It seems to me that a trial using a lower dose and only treating for 4 days is hardly sufficient to claim that nicotine patches “are not recommended.”

Nicotine and Anxiety

A review of nicotine receptors reported that these receptors help regulate mood and anxiety. In a study using mice, low doses of nicotine calmed anxiety while higher doses made it worse. Another review also found nicotine can reduce or increase anxiety, depending on the dose. This study also found the type of anxiety and possibly genetics can influence the effects of nicotine on anxiety.

Nicotine and Memory Decline Associated with Down Syndrome

People with Down syndrome have a very high risk of developing memory decline as they age. Two small studies from 2000 and 2001 involving adults with Down syndrome applied a 5 mg nicotine patch once and then measured attention. Both found modest improvements in attention and processing speed. However, each study included only 5 to 8 people, so the findings do not prove nicotine improves attention.

Nicotine and HIV

People living with HIV can develop memory and thinking problems, called “HIV-associated neurocognitive disorder” or HAND. A 2025 review suggests nicotine protects brain cells by reducing inflammation. Also, a study found that nicotine reduced memory impairment in rats that were genetically engineered to carry HIV proteins. However, human evidence remains inconsistent.

Nicotine, Alzheimer’s Disease and Mild Cognitive Impairment (MCI)

A trial in 8 Alzheimer’s patients found nicotine patches (5-10 mg/day) applied for 4 weeks improved attention but not memory. A Cochrane review, which is typically the gold standard for summarizing medical evidence, concluded there’s no trial evidence that nicotine treats Alzheimer’s disease. But let me add something here. The authors of this review looked at only 1 study of 8 patients (the study referenced above) and concluded that there is “No evidence of the efficacy of nicotine for Alzheimer’s disease.” A single study of 8 patients lasting only 4 weeks using a low dose of daily nicotine found improved attention but not memory. This hardly seems like a reason to discourage further exploration of this potential treatment.

A 2012 pilot trial of 74 people with mild cognitive impairment found six months of nicotine patches noticeably improved attention and memory. Researchers were hopeful enough to run a much bigger follow-up, the MIND trial, testing nearly 350 people for two full years. People wore a patch up to 21 mg/day for 16 hours/day. The results showed no significant benefit for memory. However, nearly half (160 participants) dropped out and did not complete the study.

Nicotine and Tourette’s Syndrome

Some of the more encouraging results come from Tourette’s syndrome. In one small study, chewing nicotine gum reduced tics in patients already taking a standard medication (haloperidol). Another study found 20 mg of nicotine applied as a patch for just 2 days cut tic severity in half, with benefits lasting up to four weeks. Nicotine is now viewed as a potential treatment for Tourette’s syndrome.

Nicotine patches (up to 22 mg/day) were found to help people with ulcerative colitis. In young adults with ADHD, a single nicotine dose (7 mg for 45 minutes) improved cognitive performance. In schizophrenia, a review of 29 studies found a single dose of nicotine improved attention, working memory, and executive functions. Several studies have shown improvement in Parkinson’s disease symptoms following nicotine administration. These can be viewed here, here, here, here, and here.

Nicotine Isn’t Risk-Free

None of this means nicotine is safe to use casually. A large review found that nicotine, especially high doses, can be associated with significant side effects. However, another study found nicotine patches were safe for people with heart disease when used for two weeks. Side effects of nicotine may include nausea, insomnia, and skin irritation.

The Bottom Line

Nicotine is an interesting chemical. It can sharpen attention and reduce symptoms of depression, anxiety, tics, colitis, memory impairment, ADHD, and Parkinson’s disease. Additional studies are needed to explore the potential benefits of nicotine, and to determine the appropriate dose range for this medicine.