Caffeine, alcohol, screens and sleep: everyday amplifiers of anxiety

It is 7.10 am. The alarm has already gone off three times. Your first thought, before you even open your eyes: what time is it and what is waiting for you today. Your second: where is your phone. You read two news stories and three messages, then press the button on the coffee machine in the kitchen. At ten, a second coffee, because the meeting is long. At three, a third, because the afternoon slump hits. In the evening a glass of wine “to unwind”, then another half hour on your phone in bed. You fall asleep around midnight, and at three you wake with your heart beating too fast and a thought that won’t stop.

None of this is unusual. That is exactly why it is so easy to overlook how strongly these everyday fragments can affect anxiety. Caffeine, alcohol, screens and too little sleep do not cause anxiety. But they are amplifiers: they turn up the volume of an alarm that is already there. In this post I will try to explain how each of them works, why they link up into a loop, and what you can do without turning it all into yet another project of fixing yourself.

Amplifiers, not causes

At its core, anxiety is a system for detecting danger. When the brain perceives a threat, it prepares the body to respond: the heart beats faster, muscles tense, breathing becomes shallower, attention narrows. I have written more about what happens in the brain during this in What happens in the brain during anxiety — and why the body reacts before you think.

Amplifiers work in two ways. Some directly give the body signals that resemble anxiety — a faster pulse, trembling, restlessness. The brain reads these signals as proof that something is wrong, and the alarm grows louder. Others weaken what normally calms the alarm: sleep, rest, the feeling that the day is over.

How strong this effect can be was shown neatly in a study published in 2020 by Eti Ben Simon, Matthew Walker and colleagues at the University of California, Berkeley. After a single sleepless night, healthy adults reported noticeably higher anxiety than after a night of sleep — for some, anxiety levels were up to 30% higher. One night. In people who already struggle with anxiety, this effect can be even more pronounced.

It is important to say what this post is not. It is not a list of prohibitions, and it is not a hint that your anxiety is the result of bad habits. We reach for coffee, wine and our phones for understandable reasons: to get through the day, to relax, not to be alone with our thoughts. The aim is to understand what these helpers give you and what they quietly take away.

Caffeine: when the body mistakes alertness for alarm

Caffeine works by occupying receptors for adenosine — a substance that builds up in the brain over the day and tells us we are tired. When the receptors are occupied, the tiredness signal doesn’t get through. You feel more awake. At the same time caffeine stimulates the release of adrenaline, so your heart beats faster and your muscles tense.

For most people this is a pleasant alertness. But for someone prone to anxiety, the line between alertness and alarm is thin. A faster pulse, slightly shaky hands, a sense of restlessness — these are the same signals the body knows from anxiety. The brain doesn’t always distinguish whether the heart is beating faster because of coffee or because of danger. In people with panic attacks this is especially marked: as early as the 1980s researchers showed that high doses of caffeine trigger anxiety and panic symptoms more often in people with panic disorder than in others.

In 2015 the European Food Safety Authority (EFSA) concluded that for healthy adults up to 400 mg of caffeine a day does not pose a health risk, and that single doses of up to 200 mg do not either. A cup of coffee usually contains somewhere between 80 and 100 mg, depending on how it is made, and energy drinks, tea and chocolate add their share. But this limit is about the health of the heart and body, not about anxiety. For someone who is sensitive, even one strong coffee can be too much.

The other part of the story is timing. Caffeine leaves the body slowly: on average, the amount in your blood halves in about five hours, but in individuals this can be considerably shorter or longer. A 2013 study by Christopher Drake and colleagues showed that a large dose of caffeine taken six hours before bed cut sleep by more than an hour — even though participants often didn’t notice this themselves.

Why some people tolerate it and others don’t

We all know someone who drinks an espresso after dinner and sleeps like a baby, and someone whose morning coffee alone ruins the day. These differences are not imagined. In the early 2000s the researcher Harriet de Wit and colleagues showed that variations in the gene for the A2A adenosine receptor are linked to how strongly a person’s anxiety rises after caffeine. The speed at which it is cleared is also affected by liver enzymes, smoking, some medications and pregnancy.

This means two things. First: if coffee makes you restless while others are fine, you are not “too weak”. Your body simply processes this substance differently. Second: general recommendations are a starting point, not a rule for you. The best source of data is your own experience — and that is exactly what we will explore later with the exercise.

In Slovenia, coffee is also a social ritual. “Shall we go for a coffee?” often doesn’t mean caffeine but conversation, a break, company. There is no need to give that up. If you find that caffeine doesn’t agree with you, you can keep the ritual and change what is in the cup.

Alcohol and “rebound anxiety” the next day

On the surface, alcohol is the opposite of caffeine. In the evening it calms, softens your thoughts and makes conversation easier. That is precisely why it is one of the most common ways people — often without realising it — regulate anxiety. But its effect has two halves.

Alcohol acts on the GABA system, the brain’s main inhibitory system, and at the same time dampens the excitatory glutamate system. That is why you feel calmer at first. But once the alcohol has been broken down, the brain tries to return to balance — and often swings the other way. The result is something many people know: the morning after an evening with a few drinks is tense, restless, full of vague worries and shame. In English the playful term hangxiety has caught on; we might call it rebound anxiety.

Part of this rebound anxiety is down to sleep. A 2013 review by Irshaad Ebrahim and colleagues showed that alcohol does shorten the time it takes to fall asleep and deepens sleep in the first half of the night, but fragments it in the second half: sleep becomes lighter, there is more waking, and REM sleep is disrupted. You can find more on this in the knowledge base under alcohol and sleep.

The conversation might go like this (composite, not a real person):

“I don’t drink much. Just a glass or two in the evening, to relax.”
“And what are the mornings like?”
“Tense. But that’s because of work.”
“Have you ever noticed what the mornings are like after evenings when you don’t drink anything?”
“… Actually, no. There haven’t been any of those evenings for a long time.”

This conversation is not an accusation. A glass of wine in the evening is perfectly fine for many people. But when it becomes the only way you can calm down, alcohol may return in the morning, with interest, the anxiety it soothed the night before. Research has long described how anxiety disorders and alcohol problems often occur together and can keep each other going. I have described how drinking is quietly normalised in Slovenia in Alcohol in the Slovenian family: how it is normalised until it breaks.

Screens and news: an alarm in your pocket

A phone is not a substance you consume, but it can act on anxiety in a similar way. Its effect has several layers.

News. The brain is built to give threats priority attention. The news we read is selected by exactly that criterion. A study by Alison Holman, Dana Rose Garfin and Roxane Silver after the 2013 Boston Marathon bombing found that people who followed coverage of the attack for six hours or more a day reported higher acute stress than some of those who were directly at the scene. Repeatedly watching distressing content is not just keeping informed. The body experiences it as repeated exposure.

Constant availability. Every notification is a small call on your attention. When your phone is always with you, the day never really ends — there is always one more message you ought to answer.

The evening. A phone in bed postpones the moment when you are left alone with your thoughts. That is understandable, since thoughts before sleep are often the hardest. But postponing them doesn’t make them smaller; it just moves them into the late night. I wrote about why thoughts start spinning just when they should be switching off in Overthinking at bedtime.

Sleep: the foundation we don’t see

If I had to choose the most important of the four amplifiers, I would choose sleep. Sleep is not just rest. During sleep, especially REM sleep, the brain processes the emotional experiences of the day. Research shows that after a sleepless night the amygdala — the part of the brain that detects threats — reacts more strongly, while its connection with the prefrontal cortex, which normally calms it, is weaker. Put simply: after a bad night the brakes are weaker and the alarm is louder.

That is why everything seems to hurt more after a sleepless night — this is the subject of Sleep and emotion: why everything hurts more after a bad night. And that is why anxiety and insomnia so often reinforce each other: anxiety makes it hard to sleep, and poor sleep strengthens anxiety.

Sleep is also the point where all four amplifiers meet. Caffeine shortens it, alcohol fragments it, the phone postpones it. Short of sleep, we turn to coffee again in the morning — and the loop closes. When insomnia lasts for a long time, it is often no longer a sleep problem but a state of constant arousal in the nervous system; more on this in Hyperarousal: why chronic insomnia is not a sleep problem but an arousal problem.

How the amplifiers link into a loop

On its own, each of these influences is small. Coffee won’t give you an anxiety disorder, and neither will a glass of wine. The problem is that amplifiers rarely appear alone. They often run in a sequence that seems entirely logical:

• you sleep badly, so in the morning you need more coffee;
• coffee raises your tension during the day, so it is harder to settle in the evening;
• in the evening you reach for a glass or your phone to relax;
• as a result, your sleep is lighter and shorter;
• the next day your anxiety is higher and your need for coffee greater.

This loop is not a sign of weak willpower. It is a reasonable attempt to get through the day with the means at hand. That is exactly why it is useful to see it — because then you can break it at the point that is easiest for you. This loop often spins hardest in people who seem to have everything under control on the outside; I wrote about this in High-functioning anxiety.

Exercise: a week of observation

This exercise is not a diet, and it is not a challenge you have to “win”. It is a piece of research in which you are both the researcher and the subject. It takes one week of observation and one week of a small change.

1. Every evening, write down four things: when you had your last coffee (or other caffeinated drink), whether you drank alcohol and how much, when you last looked at your phone, and roughly how many hours you slept the night before.
2. Rate your anxiety twice a day from 0 to 10 — in the morning when you get up and in the evening. Don’t think about it too long; the first number is enough.
3. After seven days, look at your notes together. Are the mornings after evenings with alcohol different? Are the nights after a late coffee shorter? Do you start the day more tense after an evening with your phone in bed?
4. Choose just one small change at the point that seems easiest — for example, your last coffee before 2 pm, or leaving your phone in another room in the evening.
5. Observe the same things the following week and compare. Don’t look for perfection, look for a difference.

If during the exercise you notice that one of these things is very hard to cut down — that you can’t fall asleep without alcohol, or can’t get through the day without coffee — that is valuable information too. It tells you that this helper is carrying you more than you thought.

Where this explanation falls short

I want to be clear here, because thinking about amplifiers can turn against you.

You won’t cure an anxiety disorder with less coffee. If you have generalised anxiety, panic attacks or social anxiety, changing your habits can make daily life easier, but it won’t resolve the core. Anxiety has roots in experiences, relationships and learned patterns that need a different kind of work.

Habits can be a consequence, not a cause. Often you don’t sleep badly because you look at your phone; you look at your phone because you can’t fall asleep. If you keep fixing the consequence, you may overlook what is really keeping you awake.

Fixing habits can become a new source of anxiety. In people who tend towards control, concern about the “right” sleep, diet and phone use can quickly turn into yet another area where it is possible to make mistakes. If you notice that thinking about caffeine, alcohol or sleep frightens you more than it calms you, stop. The goal is less anxiety, not a perfect life.

Not everything is psychological. A racing heart, trembling and restlessness can also have physical causes — from the thyroid to heart rhythm and medication side effects. If physical symptoms worry you, see a doctor first. You may also find it helpful to read Panic or your heart? What to check with your doctor before starting therapy.

When to seek help

I would particularly like to mention alcohol. If you drink every day, if you need more and more to get the same effect, or if trembling, sweating or strong restlessness appear when you don’t drink, talk to your GP about it first. With regular, heavier drinking, stopping suddenly can be dangerous and needs to be done under medical supervision. This is not a matter of willpower but of a body that has adapted to alcohol.

Seek help, too, when your anxiety stays high despite changes, when sleep hasn’t brought you rest for weeks, or when you notice that you are actually using the amplifiers to avoid something you don’t want to feel. In therapy we won’t just talk about how much coffee you drink, but about what coffee, wine or your phone help you bear — and whether you might bear it differently, perhaps in a relationship in which you don’t have to be alone.

If anxiety overwhelms you and you need to talk to someone straight away, in Slovenia you can call the crisis line Klic v duševni stiski on 01 520 99 00 (every day from 7 pm to 7 am) or the Samaritans’ helpline on 116 123 (24 hours a day). In an emergency, call 112.

What to remember

• Caffeine, alcohol, screens and too little sleep do not cause anxiety, but they amplify it.
• Caffeine gives the body signals that resemble anxiety; how strongly depends a great deal on the individual — including their genes.
• Alcohol calms you in the evening but fragments sleep and can bring rebound anxiety the next day.
• A single sleepless night can noticeably raise anxiety; sleep is the point where all the amplifiers meet.
• Observe rather than moralise — and if you drink regularly and heavily, talk to a doctor before making changes.