A new study explores the boundary between everyday caffeine and panic

A standard cup of coffee will likely not trigger a panic attack in people diagnosed with panic disorder, though it may make them more likely to avoid uncomfortable situations. A new study published in the Journal of Psychopharmacology shows that consuming a moderate amount of caffeine does not elevate subjective anxiety levels in susceptible individuals. The research provides practical guidance for people managing their anxiety symptoms while navigating everyday dietary habits.

Panic disorder is a psychiatric condition recognized by sudden attacks of intense fear. These attacks bring a rush of physical symptoms, including a racing heart, shortness of breath, dizziness, and a feeling of numbness. People diagnosed with this condition also carry persistent worry about when the next panic attack might strike.

This worry often leads to maladaptive avoidance behavior. A person might stop going to the movie theater or the gym for fear that these environments will trigger a panic episode. By avoiding these places, the person misses out on rewarding experiences and loses the opportunity to learn that their physical symptoms are not actually dangerous.

Previous research into caffeine and anxiety has established clear negative effects at extremely high doses. Consuming more than four hundred milligrams of caffeine, roughly the equivalent of four or five cups of coffee, triggers panic attacks in about half of all people with panic disorder. These high doses also raise general subjective anxiety levels in healthy adults.

However, people rarely consume such massive amounts of caffeine in a single sitting. Clinical recommendations often advise patients with panic disorder to abstain from all caffeine entirely just to be safe. Yet, the effects of a typical serving size on this specific population have remained largely unexamined until now.

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Psychology researcher Johanna M Hoppe at Uppsala University in Sweden led a team to investigate how a normal physiological dose of caffeine impacts people with panic disorder. Working with colleagues Johannes Björkstrand, Johan Vegelius, Lisa Klevebrant, Malin Gingnell, and Andreas Frick, she set out to measure both subjective anxiety and bodily arousal. They wanted to see if the stimulant changed how people reacted to stressful emotional tasks.

The team recruited twenty nine adults diagnosed with panic disorder and fifty three adults without any mental health conditions. All the participants were habitual low caffeine consumers. They normally took in less than three hundred milligrams of caffeine across an entire week, meaning they would not experience severe withdrawal symptoms during the study.

To participate, the volunteers abstained from all caffeine for thirty six hours. They then visited the laboratory for two separate sessions scattered a few days apart. During one visit, they received a capsule containing one hundred and fifty milligrams of caffeine, an amount broadly comparable to one and a half cups of coffee.

During the other visit, the participants received an identical placebo capsule containing an inert powder made of microcrystalline cellulose. The study used a double-blind trial design. This means neither the participants nor the researchers in the room knew which capsule was administered on which day.

After taking the capsule, participants rested for thirty minutes to let the substance absorb into their bloodstream. The researchers asked them to rate their subjective anxiety levels on a scale from zero to one hundred. They then engaged in a series of computerized emotional testing activities.

The first activity tested emotional reactivity. Participants looked at virtual photographs of faces displaying happy, fearful, or entirely neutral expressions. Simultaneously, they listened to matching audio clips over a pair of headphones, hearing noises like laughter, screams, or simple humming.

While the visual and audio stimuli played, the researchers measured the participants’ skin conductance response. Skin conductance tracks the slight variations in sweat gland activity on the hand, providing a biological marker for sympathetic nervous system arousal. This metric reveals how highly an individual’s fight-or-flight response is activated by what they are looking at.

Next, the volunteers completed an approach-avoidance conflict game. Participants were shown a series of virtual doors on screen and had to choose which one to open. Selecting a safe, neutral door yielded zero points but showed a calming image and sound.

Selecting a more threatening door offered a varying point reward, but it exposed the participant to unpleasant medical images or panic-inducing sounds like heavy panting. This forced a decision between earning a reward and avoiding a negative experience. The game measures costly avoidance, determining how often a person willingly gives up points just to stay comfortable.

Following the tasks, participants reported on their interoceptive processing. Interoception is the psychological ability to notice internal bodily signals like a beating heart or a sudden skipped breath. The researchers asked if these internal signals caused anxiety or impaired their ability to focus on the computer screen.

The results from the experiment contradicted the team’s initial expectations about anxiety generation. The moderate dose of caffeine did not elevate subjective anxiety levels during the resting period for either group. Out of the eighty two total participants completing both sessions, only one panic attack occurred, happening in a single patient during the face viewing task.

The skin conductance data showed that caffeine increased physical arousal across the board. Both the healthy adults and the adults with panic disorder sweat slightly more in response to the emotional faces when under the influence of the stimulant. However, the caffeine effects did not differ in magnitude between the two groups.

The approach-avoidance game revealed a distinct behavioral shift. When participants had taken the caffeine capsule, they were more likely to forfeit the game points to avoid the unpleasant images and sounds. This caffeine-induced increase in costly avoidance behavior happened equally for both the panic disorder patients and the healthy adults.

The researchers noted that patients with panic disorder already display more costly avoidance behavior at a baseline level compared to healthy peers. While caffeine increased everyone’s desire to avoid aversive stimuli, it did not uniquely target the vulnerable patient group. The stimulant simply amplified a basic human tendency to step away from stressful situations.

Participants also reported that caffeine impaired their external attention. They found themselves distracted by their own internal bodily sensations during the computer tasks. However, noticing these physical signals did not translate into a feeling of increased panic or overwhelming subjective fear.

The scientists concluded that normal serving sizes of caffeine are generally safe from an anxiety perspective for people with panic disorder. The stimulant does not seem to trigger the intense cognitive feedback loop that leads to full panic attacks at this dosage. A tailored medical approach regarding dietary habits might be more appropriate than universal recommendations to strictly abstain from all coffee.

Increased avoidance behavior could present unique challenges in a therapeutic setting. Exposure therapy requires patients to actively engage with the exact situations and external stimuli they fear most. If a morning cup of coffee makes a person more prone to avoid discomfort, they might struggle to complete their assigned therapy exercises.

The authors outlined a few caveats regarding their investigative work. Recruiting eligible participants proved difficult, resulting in a slightly small sample size. Many potential volunteers drank too much daily coffee or had overlapping mental health conditions that excluded them from the initial screening process.

The group of participants diagnosed with panic disorder was overwhelmingly female in this study. Future experiments with an evenly mixed group might clarify if biological sex alters how typical caffeine doses affect baseline anxiety levels. The reliance on purely subjective self-reports for interoceptive awareness offers another limitation that future biological tracking tools could resolve.

Future research should investigate a wider range of moderate caffeine doses. Testing daily consumption amounts between one hundred and fifty milligrams and four hundred milligrams would help identify the exact threshold where anxiety symptoms begin to spike. Until then, the choice to enjoy a mild cup of coffee seems to pose little acute risk for panic induction.

The study, “Acute effects of 150 mg caffeine on subjective, physiological, and behavioral components of anxiety in panic disorder and healthy controls – A randomized placebo-controlled crossover trial,” was authored by Johanna M Hoppe, Johannes Björkstrand, Johan Vegelius, Lisa Klevebrant, Malin Gingnell, and Andreas Frick.