20 Jul 2025

Nicotine Replacement and ADHD: Cognitive and Health Impacts

Cognitive and Behavioral Effects of Nicotine in ADHD Adults

•   Attention and Focus: Nicotine acts as a stimulant on the brain’s nicotinic acetylcholine receptors, leading to enhanced neurotransmitter release (e.g. dopamine, norepinephrine) that can sharpen attention. Studies have shown that adults with ADHD experience improved sustained attention and faster processing after nicotine administration. For example, in a placebo-controlled trial, nicotine patches led to significantly better performance on attention tasks – participants had quicker reaction times and more consistent responses on a Continuous Performance Test (CPT) . These benefits were observed even in ADHD individuals who were not smokers (thus not just a withdrawal relief effect), suggesting a true cognitive-enhancing action of nicotine . Many ADHD patients subjectively report that nicotine (from smoking or NRT) helps them “focus” or feel more alert, which aligns with experimental evidence of nicotine-induced vigilance improvements.
•   Working Memory: Some research indicates nicotine can modestly improve aspects of working memory in ADHD, though results are mixed. Nicotine’s cognitive-enhancing effects extend to memory domains – it has been associated with better short-term memory and recognition memory in both general populations and ADHD groups . In young adults with ADHD, a single 7 mg nicotine patch tended to improve recognition memory accuracy (showing a strong trend in one study) . However, the effect may depend on baseline performance: one trial in non-smoking adults divided by attentiveness found that those with low baseline attention (analogous to ADHD-like deficits) showed improved memory and fewer errors under nicotine, whereas those with high baseline cognitive performance experienced no memory benefit or even slight impairment . This suggests nicotine may optimize cognitive function – helping to normalize deficits in working memory for ADHD individuals, but offering little advantage (or potential overstimulation) for neurotypical individuals performing at peak .
•   Impulse Control (Inhibitory Control): A core challenge in adult ADHD is impulsivity and difficulty inhibiting inappropriate responses. Nicotine appears to aid in this domain. Research with ADHD participants has demonstrated that nicotine can improve behavioral inhibition – essentially giving better “braking power” on impulses. In one placebo-controlled study, a nicotine patch significantly reduced stop-signal reaction time, meaning ADHD adults were quicker and more successful at halting an ongoing response in a Stop Signal Task . Notably, this improvement in inhibitory control was achieved without sacrificing accuracy or increasing baseline reaction times . Similarly, nicotine reduced the number of commission errors (false alarms) on continuous performance attention tests, indicating fewer impulsive mistakes . These objective findings support anecdotal reports that nicotine can have a calming, self-regulating effect for ADHD users – possibly by engaging brain networks involved in executive control. There is even evidence of a trend toward increased tolerance for delay under nicotine (i.e. slightly reduced delay aversion) in ADHD patients , hinting that nicotine might help with the impulsive preference for immediate rewards, although more research is needed on that aspect.
•   Mood and Arousal: Nicotine’s effects on cognitive function often come with changes in mood and arousal level that can be relevant for ADHD. Nicotine typically increases “vigor” or alert energy while reducing fatigue . In ADHD adults, short-term nicotine has been associated with feeling more motivated and less sluggish during cognitive tasks. Moreover, because ADHD in adults frequently coexists with mood difficulties (depression, anxiety), it is noteworthy that nicotine may transiently alleviate some of these symptoms. One case report documented a 43-year-old ADHD patient whose inattention and comorbid depression/anxiety completely resolved within an hour of applying a low-dose nicotine patch . His mood and focus improved together while the nicotine was active, and although these benefits partially faded after removing the patch, they returned each time nicotine was reintroduced . This mood-elevating aspect is likely linked to nicotine-induced dopamine release and other neurochemical interactions. However, it’s important to distinguish acute effects from long-term impact: nicotine can momentarily improve anxiety or mood, especially by quelling withdrawal in dependent users, but long-term nicotine use is not a cure for underlying anxiety/depression and can lead to its own mood stresses (discussed more below).

How Nicotine Enhances Cognition: Underlying these cognitive/behavioral effects is nicotine’s pharmacology. Nicotine binds to nicotinic acetylcholine receptors in the brain, which stimulates the release of several neurotransmitters involved in attention and reward (dopamine, norepinephrine, acetylcholine, etc.). Research has implicated cholinergic pathways in ADHD’s cognitive symptoms, suggesting why a nicotinic agonist could help . In fact, the improvements seen with nicotine parallel some effects of traditional ADHD stimulant medications: better focus, quicker cognitive processing, and improved self-control. Due to such findings, scientists have proposed that nicotinic compounds might be potential therapeutic aids for ADHD. Small trials in the 1990s and 2000s concluded that nicotine deserved further exploration as an ADHD treatment , and these foundational results have spurred ongoing interest in nicotinic receptor drugs for cognitive enhancement. That said, practical use of nicotine for ADHD has been limited, partly because of side effects and the obvious concerns about addiction (see “Health Impacts” below). For example, transdermal nicotine studies in adolescents and children with ADHD noted that while symptoms improved, the nicotine patches caused side effects (nausea, dizziness, etc.) that made this therapy less viable for younger patients . In adults, low doses are somewhat better tolerated, but even in a controlled study of young adult ADHD patients, 3 out of 15 subjects had to drop out due to nicotine side effects like nausea or lightheadedness . Thus, nicotine’s cognitive benefits for ADHD must be weighed against its side effect profile.

Broader Health Impacts of Nicotine in ADHD Users

Beyond cognition, nicotine ingestion – whether via NRT patches/gums or nicotine pouches – has systemic effects on health. When considering adults with ADHD using these products, we should examine cardiovascular impacts, addiction potential, and mental health implications:
• Cardiovascular Effects: Nicotine is a cardiovascular stimulant. It acutely increases heart rate and blood pressure by activating the sympathetic nervous system. In an ADHD adult, this means using a nicotine patch or pouch can cause mild hypertension, a faster pulse, and in some cases side effects like jitteriness or chest discomfort. For instance, in the aforementioned case report, a 7 mg nicotine patch initially caused the patient to experience chest discomfort by midday – essentially an indicator of too high a dose and cardiovascular strain . Once he adjusted to a lower effective dose (~3.5 mg), his blood pressure remained stable during nicotine therapy . Overall, nicotine alone (as delivered by NRT or pouches) is less harmful to the cardiovascular system than smoking cigarettes (which adds carbon monoxide and arterial toxins), but it is not benign. Long-term nicotine use can contribute to increased arterial stiffness and may aggravate hypertension in susceptible individuals. Adults with ADHD should be cautious if they have any existing heart issues or are on stimulant medication, since combining stimulants (amphetamine, methylphenidate) with nicotine could further elevate blood pressure. Common minor cardiovascular-related side effects reported with nicotine products include: rapid heartbeat, slight increase in blood pressure, and in some cases palpitations or dizziness upon standing (due to blood pressure changes). These are usually dose-dependent. It’s advisable for ADHD users of NRT to start at low doses and monitor their cardiovascular response. Clinically, nicotine is typically contraindicated in people with serious heart arrhythmias or recent cardiac events, but for healthy adults, the cardiovascular effects are moderate. Still, the risk of long-term nicotine contributing to heart disease can’t be ignored, especially if use becomes chronic.
• Addiction and Dependence Potential: Nicotine’s addictive nature is well documented, and unfortunately adults with ADHD are particularly vulnerable to nicotine dependence. Epidemiological and clinical studies consistently find that ADHD is a risk factor for earlier smoking initiation, heavier nicotine use, and greater difficulty quitting compared to the general population . The reasons are multifaceted: nicotine provides short-term relief for some ADHD symptoms, essentially acting as a form of self-medication, which positively reinforces use. Moreover, ADHD is linked to differences in brain reward pathways (often involving dopamine); nicotine directly engages these pathways, potentially producing more pronounced reinforcing (pleasurable or focusing) effects for someone with ADHD. In fact, research has found that individuals with ADHD report stronger subjective effects from nicotine. In one study of initial nicotine exposure, ADHD participants felt more dizziness and more pleasant drug effects than non-ADHD controls, indicating a heightened sensitivity to nicotine’s impact. This can make nicotine more habit-forming for them. Over time, what starts as “using a nicotine pouch for focus” can escalate into a dependence where the person feels they need nicotine to function normally. Physiologically, their brain adapts – nicotinic receptors become desensitized and upregulated – leading to tolerance and withdrawal symptoms when nicotine isn’t present.
ADHD smokers and nicotine users also experience worse withdrawal symptoms on average. When they try to quit nicotine, they often suffer intense irritability, restlessness, difficulty concentrating, depressed mood, and cravings – even more so than non-ADHD smokers who quit . One report noted that in the first several days off nicotine, adult smokers with ADHD had significantly greater mood swings and irritability than smokers without ADHD . Additionally, many ADHD individuals feel that their ADHD symptoms worsen during nicotine withdrawal (e.g. “I can’t focus at all, I’m climbing the walls”), compounding the challenge of quitting . While part of this may be the overlap between withdrawal symptoms and ADHD’s baseline symptoms, the end result is the same: quitting nicotine tends to be harder for those with ADHD. This is reflected in real-world outcomes – ADHD populations have higher relapse rates. One longitudinal study in smokers found that having ADHD predicted a lower quit success rate and a higher risk of reverting to smoking even after treatment, compared to smokers without ADHD . In summary, the addiction potential of nicotine is a major health concern for ADHD users: they are more likely to get hooked, and once dependent, they face a tougher road in breaking free. This underscores why any off-label use of nicotine for ADHD-related reasons should be approached with extreme caution and preferably under medical supervision.
• Mental Health Effects: Nicotine’s interplay with mental health can be complex, especially in adults with ADHD (who frequently have comorbid anxiety, depression, or other conditions). Acutely, nicotine often produces a calming or mood-elevating effect – smokers commonly say it relaxes them or helps relieve stress. In the short term, nicotine triggers dopamine and serotonin release, which can improve mood and reduce anxiety while the drug is active. In the case report of an ADHD adult, the nicotine patch not only sharpened his focus but also alleviated his depressive and anxious symptoms during the day . This dual benefit is part of nicotine’s appeal: it can act as both a stimulant and an anxiolytic (an anxiety-reducer) transiently. Some ADHD individuals use nicotine (consciously or unconsciously) to smooth out mood swings or self-soothe.
However, these beneficial mental health effects are short-lived and come at a cost. The other side of the coin is that nicotine dependence can worsen mental health in the long run. As the nicotine level drops (e.g., overnight or between doses), people often experience rebound anxiety, irritability, and low mood – essentially withdrawal symptoms that can feel like worsening anxiety/depression. This can create a vicious cycle where an ADHD user needs the next gum, lozenge, or pouch to feel “normal” or avoid feeling extra agitated. Indeed, some adults with ADHD have described that during periods of nicotine abstinence, their ADHD symptoms and general emotional regulation significantly deteriorated until they started using nicotine again . Chronic nicotine use has also been linked to changes in stress response; while a cigarette might immediately calm nerves, smokers on average have higher baseline stress levels than non-smokers. For ADHD individuals, this means relying on nicotine could potentially mask underlying mood disorders or make them harder to treat (since any improvements vanish when nicotine is removed). Additionally, if an ADHD person is also on prescribed medications (like stimulants or antidepressants), nicotine can interact pharmacokinetically or physiologically. Nicotine may speed up the metabolism of some antidepressants or increase blood pressure alongside stimulants, for example. On the positive side, there is some evidence that medications like bupropion (an antidepressant also used for smoking cessation) can both help with ADHD symptoms and reduce nicotine cravings , pointing to overlapping brain pathways. Physicians treating ADHD patients who are heavy smokers sometimes choose such agents to address both issues.
In summary, nicotine’s effect on an ADHD adult’s mental health can be a double-edged sword: a form of short-term self-medication that provides temporary relief of stress or dysphoria, but with the risk of long-term dependency, withdrawal-induced emotional volatility, and no true resolution of underlying psychiatric needs. It’s important to seek healthier, more sustainable strategies for mood and anxiety management rather than leaning on nicotine.
• Other Health Considerations: Nicotine is a drug with other miscellaneous effects on the body. It can suppress appetite and is associated with modest weight loss in some users (conversely, quitting nicotine often leads to appetite increase and weight gain). ADHD adults may find this effect either desirable or problematic depending on their situation. Nicotine can also cause gastrointestinal upset in some cases (nausea, acid reflux) and headaches. Nicotine pouches, specifically, can sometimes irritate the gums or mouth (they are tobacco-free but the nicotine and additives can still cause mild oral irritation or sores with heavy use). From a long-term perspective, pure nicotine has not been definitively linked to cancer (unlike tobacco smoke’s carcinogens) – so using nicotine pouches or NRT eliminates the major risks of smoking-related cancers and lung disease. Nonetheless, there is emerging research on whether chronic nicotine (absent smoking) could contribute to insulin resistance or other metabolic changes; results are not yet conclusive. The method of delivery also matters: transdermal patches provide a slow, steady dose which avoids peaks and troughs (and might carry less addiction potential), whereas oral pouches or gum give quicker, smaller spikes of nicotine that more closely mimic the smoking pharmacokinetic (and thus could be more habit-forming). For an ADHD adult considering nicotine for self-management, patches might result in more stable cognitive effects and fewer reinforcement cues than, say, repeatedly popping nicotine lozenges. In any case, the broader medical consensus is that while nicotine replacements are far safer than smoking, they are not risk-free and should ideally be used as a temporary aid (for smoking cessation) rather than a lifelong crutch – especially in a population prone to addiction.

ADHD vs. Non-ADHD Adults: Differences in Nicotine’s Effects

One of the key questions is how nicotine’s impact on an adult with ADHD compares to its impact on someone without ADHD. There are notable differences in cognitive response and in vulnerability profiles between these groups:
• Cognitive Response: Generally, nicotine can produce mild performance enhancements in any adult – it’s been shown to improve attention, alertness, and even fine motor performance in the average person . However, for neurotypical (non-ADHD) users, these improvements are relatively small and often only evident in certain conditions (e.g. when sleep-deprived or during difficult tasks). In contrast, adults with ADHD (who baseline have impairments in attention and inhibitory control) tend to experience a larger relative benefit from nicotine. Essentially, nicotine “fills in” a functional gap for them. As an example, a study that directly compared individuals with lower attentional abilities to those with higher abilities found that nicotine markedly improved performance for the low-attention group, while the high-attention (non-ADHD-like) group saw little benefit and even a decline on a complex task . This implies that nicotine acts as a cognitive normalizer: in ADHD, it can bring deficient attention or control up closer to normal levels, whereas a person who is already normal might receive no additional boost or might overshoot the optimal arousal level (leading to slight performance decrements due to jitteriness or divided attention). Similarly, improvements in reaction time consistency and error rates that are documented in ADHD subjects on nicotine are not as pronounced in non-ADHD subjects. A non-ADHD adult using a nicotine patch might feel a bit more alert or get a minor memory kick, but they’re unlikely to experience the dramatic focus “turnaround” that an ADHD adult might report. Essentially, the magnitude and significance of cognitive effects of nicotine are greater for ADHD adults because they have more room for improvement. This difference aligns with the anecdotal observation that many people without ADHD do not find nicotine helpful for complex cognitive tasks (beyond maybe a slight stimulatory effect), whereas those with ADHD might find it comparably useful to a weak dose of ADHD medication in the short term.
• Subjective Effects and Reinforcement: Beyond objective task performance, the subjective experience of nicotine often differs between ADHD and non-ADHD individuals. Adults with ADHD tend to report more pronounced positive effects from nicotine – for instance, feelings of improved concentration, reduced boredom, and even enhanced sense of well-being. Non-ADHD individuals, especially if they are not regular smokers, might mainly notice side effects (like dizziness or nausea) when first using nicotine, with only mild stimulant effects. Research supports this: in trials, ADHD participants found nicotine more pleasant and stimulating than control participants did. They were more likely to want to use it again, reflecting a higher reinforcing value. This could be tied to neurobiology – ADHD brains may receive a bigger dopamine reward signal from nicotine, whereas non-ADHD brains get a smaller reward. It’s noteworthy that some nicotine replacement trials in ADHD patients have not observed significant abuse or uncontrolled use of the nicotine medication itself . For example, kids with ADHD given transdermal nicotine in studies did not suddenly start seeking nicotine outside the study, and adults in short-term patch trials didn’t turn into regular nicotine users afterward. This suggests that when provided in a controlled, slow-release manner (like a patch) and without the behavioral cues of smoking, nicotine’s habit-forming grip can be moderated even for ADHD folks. By contrast, smoking or recreational nicotine use in ADHD is very reinforcing – not only because of nicotine, but also because of other substances in tobacco. Cigarette smoke contains MAO inhibitor compounds that amplify dopamine levels and can make nicotine’s effects more potent. These additional tobacco components may disproportionately hook ADHD smokers. In fact, a recent review highlighted that the extra ingredients in tobacco (and even certain e-cigarette flavors) boost nicotine’s dopamine effects and likely contribute to the high smoking rates in ADHD  . Pure nicotine (as in pouches or pharmaceutical NRT) lacks those extras, so it might be slightly less rewarding than a cigarette for an ADHD user – potentially translating to a somewhat lower addiction risk than smoking. Nonetheless, non-ADHD users are generally less compelled to continue nicotine use once any novelty or slight benefit wears off, whereas ADHD users may feel a persistent need for it to function optimally.
• Vulnerabilities and Health Risks: Adults with ADHD carry a higher vulnerability in terms of developing nicotine dependence, as discussed, whereas non-ADHD adults can certainly become addicted to nicotine as well, but their risk is more solely dependent on exposure and social factors (e.g. starting smoking due to peer influence). An ADHD adult might find themselves drawn to nicotine (be it cigarettes, vaping, or pouches) as a form of self-regulation, which is a unique vulnerability not present in a neurotypical person who has other means of self-regulation. This means prevention and cessation efforts may need to be tailored: An ADHD smoker might benefit from ADHD treatment optimization (to reduce the “need” for nicotine) as part of a quit plan, whereas a non-ADHD smoker might not require that element. Additionally, when quitting, ADHD smokers often need more intensive support (behavioral therapy addressing impulsivity and routine, maybe higher-dose or longer-duration NRT, etc.) given their worse withdrawal profile .
In terms of other health impacts, a non-ADHD adult using nicotine will face mostly the same physical risks (cardiovascular strain, addiction, etc.) as an ADHD adult. However, the consequences of addiction might be more severe for ADHD individuals in the context of their life: If nicotine is propping up their concentration, losing it might hit their work performance or emotional stability harder than it would for someone without ADHD. This can make the cycle of dependence more entrenched. Non-ADHD users may find it easier to quit because they don’t feel their basic daily functioning depends on that morning nicotine gum – it might just be a craving without the layer of “my ADHD symptoms come roaring back.” Thus, the psychological dependency (the belief that one needs nicotine to be normal) is often stronger in ADHD, which is a difference in the nature of addiction beyond the physical dependency that both groups develop.
• Response to Therapeutic Nicotine vs. Recreational Use: Another difference worth noting is how nicotine is used and perceived. In non-ADHD adults, nicotine pouches or NRT are typically used for smoking cessation or occasionally as a stimulant (e.g. some students might use nicotine gum while studying for an exam to increase alertness, even if they’re not smokers). In ADHD adults, the use might be more continuously therapeutic – e.g., someone might use nicotine gum throughout their workday to manage symptoms, essentially substituting or supplementing prescription stimulants. Some ADHD forums even discuss using nicotine pouches as a “lesser evil” for focus when one doesn’t want to increase their Adderall dose, for example. This difference in purpose means that ADHD users might dose nicotine in a more scheduled, needs-based way, whereas non-ADHD users might use it more sporadically or socially. From a safety standpoint, an ADHD adult on nicotine for self-medication could inadvertently end up ingesting quite a lot of nicotine over the day (to cover morning through evening focus), more so than a casual non-ADHD user would. This higher exposure could amplify health risks (like greater cardiovascular load). On the flip side, if an ADHD person is using a transdermal patch daily for cognitive reasons, they are under a more steady-state nicotine delivery which avoids spikes – potentially safer and less addictive than the behavior of a non-ADHD individual who might chew nicotine lozenges whenever stress hits (creating repetitive dopamine spikes).

In summary, while nicotine affects similar systems in ADHD and non-ADHD adults, the context and magnitude of its effects differ. Adults with ADHD often experience more significant cognitive improvements and reinforcement from nicotine, which unfortunately pairs with a higher risk of long-term dependence. Non-ADHD adults receive more modest benefits and are somewhat less likely to become addicted unless other factors (like social smoking) come into play. These differences highlight why nicotine use in ADHD is sometimes viewed through a medicinal lens (albeit an unofficial one), whereas in the general population nicotine use is typically seen purely as a health risk or vice. It also underscores the importance of targeting the root ADHD symptoms with safer, approved treatments – if those are well-managed, the drive to use nicotine may diminish, leveling the playing field so that an ADHD adult is no more drawn to nicotine than anyone else.

Conclusion

Nicotine – delivered via replacement therapies or pouches – has notable cognitive and behavioral effects in adults with ADHD. It can sharpen attention, improve reaction time, and curb impulsivity in the short term, essentially acting as a mild stimulant that targets the brain’s acetylcholine and dopamine systems. Both historical and recent research agree that nicotine can reduce ADHD symptoms in the short run , lending some biological credence to the high rates of smoking seen in this population. However, this comes with significant caveats. Nicotine may be an “easy fix” for focus, but it carries well-documented health risks: it stresses the cardiovascular system, holds a high potential for addiction, and can entangle with the mental health of the user. Adults with ADHD are more likely to get hooked on nicotine and struggle to quit, in part because nicotine not only rewards them with improved focus but also because their neurologic makeup may find nicotine extra reinforcing  . Over the long term, reliance on nicotine can exacerbate issues like anxiety when trying to abstain and does nothing to address the underlying ADHD – it only temporarily masks it.

Comparatively, non-ADHD adults who use nicotine might see some slight cognitive uptick, but they do not “need” nicotine in the way an ADHD individual might feel they do. The ADHD brain’s response profile to nicotine – greater benefits, greater cravings – means that what is a casual stimulant for one person can become a compelling self-treatment for another. This difference in response underscores a unique vulnerability of ADHD adults to nicotine’s lure.

From a research standpoint, findings old and new suggest a potential role of nicotinic pathways in ADHD. This has even spurred development of novel drugs (like agonists for specific nicotinic receptors) aiming to capture nicotine’s pro-cognitive benefits without its downsides. For now, though, nicotine itself is not an officially recommended therapy for ADHD due to its health impacts and abuse potential. Nicotine replacement products are best reserved for what they were designed for – helping smokers quit tobacco – and if an ADHD adult is using them for focus, it should raise a flag for clinicians to provide better support, whether that means optimizing ADHD medication, offering therapy for coping skills, or monitoring for emerging dependence.

In conclusion, nicotine’s duality is clear in the context of adult ADHD: it can be a cognitive enhancer and mood modulator, but also a cardiovascular stimulant and addictive drug. Its effects on focus, working memory, and impulse control in ADHD adults are real and backed by both foundational studies and recent analyses   . Yet, these benefits must be weighed against broader health consequences that affect both body and mind. Understanding these impacts allows individuals and healthcare providers to make informed choices – harnessing what is useful (e.g. by researching safer nicotinic treatments) while guarding against the risks. The goal for ADHD patients is to achieve consistent cognitive functioning and well-being without needing to lean on nicotine indefinitely, thereby avoiding trading one problem (inattention) for another (nicotine addiction).

Sources:

1.  Levin ED et al. (1996). Psychopharmacology (Berl) – Clinical trial on nicotine patches in adults with ADHD, showing improved global symptom ratings, vigilance, and mood .
2.  Potter AS & Newhouse PA (2008). Pharmacol Biochem Behav – Study demonstrating acute nicotine’s benefits on response inhibition (stop-signal task) and trends toward improved memory in young adults with ADHD .
3.  Poltavski DV & Petros T (2006). Physiol Behav – Trial in non-smoking adults with varying attention levels; nicotine improved attention in those with low baseline attentiveness but not in those with high, indicating nicotine’s performance-optimizing effect .
4.  “Transdermal Nicotine in Adult ADHD With Depression and Anxiety” – Case report (Cocores, 2008) documenting an adult whose ADHD and mood symptoms remitted on a low-dose nicotine patch , with discussion of cholinergic mechanisms in ADHD.
5.  Frontiers in Neuroscience (2022) – Scoping review by Taylor et al., examining ADHD and nicotine self-medication. Notes that nicotine (and analogs like varenicline) can reduce ADHD symptoms , but ADHD smokers are especially prone to dependence and quitting difficulties . Also discusses unique factors like tobacco MAO-inhibitors enhancing nicotine’s effects .
6.  Liebrenz M et al. (2014). BMC Psychiatry – Qualitative study on adult ADHD smokers. Reports that ADHD smokers perceive worsened ADHD symptoms during nicotine withdrawal and experience more severe withdrawal than non-ADHD individuals .
7.  Niemegeers P et al. (2018). Frontiers in Psychiatry – Review “Cognitive Effects of Nicotine: Recent Progress,” summarizing nicotine’s pro-cognitive actions on attention, working memory, etc., across populations .
8.  Additional references embedded in text above       , which provide primary-source evidence for the statements made.