The acceptable stimulant

Anuj Sean Chathley is a GP partner in North East Lincolnshire, with clinical interests in dermatology and point-of-care ultrasonography.

Recently, one of the partners at our practice generously donated a Nespresso Vertuo machine for the staff. As a coffee lover, it felt like Christmas had arrived early. Good coffee on tap, what more could one ask for? I was looking forward to indulging in daily cups of the Costa Rica Gran Lungo: smooth and balanced, with sweet cereal notes, gentle honeyed fruitiness, and a light roasted finish. (I told you I like coffee.)

One morning, while happily sipping my aromatic coffee, a colleague (whose enthusiasm for healthy living rivals his enthusiasm for reminding the rest of us about it) looked over and remarked, ‘You do drink a lot of coffee’. I dismissed the comment immediately. ‘Surely not,’ I thought, ‘I’m well within the recommended daily caffeine intake.’ Or was I?

Curiosity got the better of me. I started calculating my caffeine intake cup by cup. The result was rather less reassuring than I had expected. On an average day I was consuming almost 600 mg of caffeine, around 200 mg above the recommended maximum for healthy adults.¹

Determined to prove this wasn’t a problem, I decided to cut back. That was when I discovered something unexpected. The first few coffees of the morning were remarkably difficult to do without. Was I simply a coffee lover, or was it that I needed the coffee?

The question led me to ask: is it just me? I wondered whether anyone else had a similar relationship with coffee. So I circulated a short anonymous survey among primary care staff across North East Lincolnshire, exploring caffeine consumption and behaviours associated with caffeine use. The results were fascinating.

Over 90% of responders drank caffeine every day. Almost one-quarter believed they exceeded the recommended daily caffeine intake. Nearly half admitted they needed caffeine to feel awake or function effectively, while around one-third experienced headaches, tiredness, or irritability if they missed their usual coffee. Perhaps most strikingly, almost one-quarter felt they would struggle to work effectively without caffeine. These findings are, of course, exploratory, but they hint at a relationship with caffeine that extends beyond simple enjoyment.

The survey itself has clear limitations. It was small, locally distributed, and exploratory rather than scientific. It did not use validated caffeine dependence scales and cannot establish prevalence or causation. Nevertheless, the findings raise a broader question that extends beyond caffeine itself.

Why do so many of us feel we ‘need’ a psychoactive substance simply to get through an ordinary working day?

Yes. A psychoactive substance. Caffeine is the world’s most widely consumed psychoactive substance.² We rarely think of it in those terms. We call it coffee. For most adults, coffee is also the single largest dietary source of caffeine, accounting for the majority of caffeine intake in many populations worldwide.³

For most people, moderate caffeine consumption is remarkably safe and may even offer health benefits. It has consistently been shown to improve alertness, attention, vigilance, and reaction time, particularly during periods of fatigue.⁴

Like any psychoactive substance, however, caffeine also has recognised adverse effects. Higher intakes may contribute to anxiety, tremor, insomnia, palpitations, and gastrointestinal disturbance. Regular use leads to tolerance, meaning progressively larger amounts may be required to achieve the same stimulating effects. Abrupt reduction can produce withdrawal symptoms including headache, fatigue, reduced alertness, and irritability.^5,6

So yes, caffeine is a psychoactive substance and potential dependence to it is well established. Yet caffeine occupies a curious protected status. We joke about it openly. Entire workplace cultures are built around it. Coffee rounds are viewed almost as team-building exercises rather than pharmacological rituals. Familiarity, however, should not prevent reflection.

If another substance routinely produced withdrawal headaches, cravings, tolerance, and the feeling that we could not perform effectively without it, we might be having a very different conversation.

Maybe we’re asking the wrong question. Perhaps the issue isn’t whether coffee is good or bad. Perhaps the more interesting question is why so many clinicians feel they need it simply to get through an ordinary working day. Coffee isn’t going anywhere, nor should it. For most of us, the morning coffee remains one of life’s simple pleasures. So the concern isn’t the coffee, the concern is what it may be masking.

If increasing numbers of clinicians feel they need caffeine simply to function, perhaps the real issue isn’t what’s in the mug but what’s behind it: chronic fatigue, relentless workload, emotional exhaustion, inadequate recovery, the gradual normalisation of working beyond our physiological limits, and the use of a socially accepted stimulant to cope.

Perhaps coffee isn’t the story. Perhaps it’s the symptom.

References
1. US Food and Drug Administration. Spilling the beans: how much caffeine is too much? 2024. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much (accessed 28 Aug 2026).
2. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on the safety of caffeine. EFSA Journal 2015; 13(5): 4102.
3. Verster JC, Koenig J. Caffeine intake and its sources: a review of national representative studies. Crit Rev Food Sci Nutr 2018; 58(8): 1250–1259.
4. Smith A. Effects of caffeine on human behavior. Food Chem Toxicol 2002; 40(9): 1243–1255.
5. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl) 2004; 176(1): 1–29.
6. Meredith SE, Juliano LM, Hughes JR, Griffiths RR. Caffeine use disorder: a comprehensive review and research agenda. J Caffeine Res 2013; 3(3): 114–130.

Featured photo by Mike Kenneally on Unsplash.