For people diagnosed with panic disorder, drinking a standard cup of coffee won’t trigger a panic attack, but they’re more likely to avoid unpleasant situations. A new study published in the Journal of Psychopharmacology shows that consuming moderate amounts of caffeine does not increase subjective anxiety levels in susceptible people. This study provides practical guidance for people to manage anxiety symptoms while implementing daily eating habits.
Panic disorder is a mental illness recognized by sudden bouts of intense fear. These attacks cause rapid physical symptoms such as a racing heart, shortness of breath, dizziness, and numbness. People diagnosed with this condition have constant anxiety about when their next panic attack will occur.
This worry often leads to maladaptive avoidance behaviors. A person may stop going to the movies or the gym for fear that these environments will trigger a panic attack. By avoiding these places, people miss out on rewarding experiences and the opportunity to learn that their physical symptoms are not actually dangerous.
Previous studies on caffeine and anxiety have demonstrated clear negative effects at very high doses. Consuming more than 400 milligrams of caffeine, roughly equivalent to four to five cups of coffee, triggers a panic attack in about half of people with panic disorder. These high doses also increase general subjective anxiety levels in healthy adults.
However, people rarely consume such large amounts of caffeine at once. Clinical recommendations often advise patients with panic disorder to completely avoid caffeine to be on the safe side. However, the influence of typical dietary amounts on this specific population remains largely unexplored to date.
Johanna M. Hoppe, a psychology researcher at Uppsala University in Sweden, led a team that investigated how normal physiological doses of caffeine affect panic disorder patients. In collaboration with colleagues Johannes Björkstrand, Johann Wegelius, Lisa Klebrandt, Marin Ginner, and Andreas Frick, she set out to measure both subjective anxiety and physical arousal. They wanted to see if stimulants change people’s reactions to stressful emotional tasks.
The team recruited 29 adults diagnosed with panic disorder and 53 adults without any mental illness. All participants were chronic low caffeine drinkers. Typically, they consumed less than 300 milligrams of caffeine throughout the week, meaning they did not experience severe withdrawal symptoms during the study.
To participate, volunteers avoided all caffeine for 36 hours. They then visited the lab for two sessions a few days apart. During one visit, they received capsules containing 150 milligrams of caffeine. This is roughly equivalent to one and a half cups of coffee.
At other visits, participants received identical placebo capsules containing an inert powder made of microcrystalline cellulose. A double-blind study design was used in this study. This means that neither the participants nor the researchers in the room knew which capsules were administered on which days.
After ingesting the capsules, participants rested for 30 minutes to allow the substance to be absorbed into the bloodstream. Researchers asked participants to rate their subjective anxiety levels on a scale of 0 to 100. They then engaged in a series of computer-based emotion testing activities.
The first activity tested emotional reactivity. Participants viewed virtual photographs of faces with happy, fearful, or completely neutral expressions. At the same time, they listened to matching audio clips in headphones and heard noises such as laughter, screams, or simple humming.
While the visual and auditory stimuli were played, the researchers measured participants’ skin conductance responses. Skin conductance tracks subtle changes in sweat gland activity on the hands and is a biological marker of sympathetic nervous system arousal. This index reveals the extent to which an individual’s fight-or-flight response is activated by what they see.
Volunteers then completed an approach-avoidance collision game. Participants were shown a series of virtual doors on a screen and had to choose which one to open. Choosing a safe, neutral door gave you zero points but a calming image and sound.
Choosing the more threatening door will result in various point rewards, but will also expose participants to disturbing medical images and panic-inducing sounds, such as heavy gasping. This forced them to decide between reaping rewards and avoiding negative experiences. This game measures costly avoidance by determining how often a person is willing to give up points just to maintain comfort.
After the task, participants reported on their interoceptive processing. Interoception is the psychological ability to notice internal body signals, such as a heartbeat or sudden breathing. The researchers asked whether these internal signals could cause anxiety or impair a person’s ability to concentrate on a computer screen.
The results of the experiment contradicted the team’s initial expectations regarding the production of anxiety. Moderate doses of caffeine did not increase subjective anxiety levels during the resting period in either group. Out of a total of 82 participants who completed both sessions, only one panic attack occurred in one patient during the face viewing task.
Skin conductance data showed that caffeine increases overall physical alertness. Both healthy adults and adults with panic disorder sweat slightly more when under the influence of stimulants in response to emotional facial expressions. However, the magnitude of the caffeine effect did not differ between the two groups.
Approach-avoidance games revealed clear behavioral changes. If participants ingested caffeine capsules, they were more likely to give up game points to avoid unpleasant images or sounds. This caffeine-induced increase in costly avoidance behavior occurred equally in both panic disorder patients and healthy adults.
The researchers noted that panic disorder patients already exhibited more costly avoidance behaviors at baseline levels compared to healthy patients. Although caffeine increases everyone’s desire to avoid aversive stimuli, caffeine was not specifically targeted to vulnerable patient groups. Stimulants simply amplify the basic human tendency to distance yourself from stressful situations.
Participants also reported that caffeine impairs external attention. They found themselves distracted by their own internal physical sensations while working on the computer. However, awareness of these physical signals did not lead to increased panic or an overwhelming subjective feeling of fear.
Scientists have concluded that for people with panic disorder, caffeine in normal doses is generally safe from an anxiety perspective. This stimulant does not seem to cause the intense cognitive feedback loop that causes a full-blown panic attack at this dose. An individualized medical approach to dietary habits may be more appropriate than a universal recommendation to strictly abstain from all coffee.
Increased avoidance behavior can pose unique challenges in treatment settings. Exposure therapy requires patients to actively engage with the exact situations or external stimuli that they fear most. If drinking a cup of coffee in the morning makes it easier to avoid discomfort, you may have a hard time completing assigned therapy exercises.
The authors outlined several considerations regarding research work. Recruiting eligible participants proved difficult, resulting in a somewhat small sample size. Many potential volunteers were excluded from the initial screening process because they drank too much coffee each day or had a combination of mental health conditions.
In this study, the group of participants diagnosed with panic disorder was overwhelmingly female. Future experiments with evenly mixed groups may reveal how typical caffeine intake affects baseline anxiety levels depending on biological sex. Reliance on purely subjective self-reports of interoceptive awareness provides another limitation that future biological tracking tools may be able to address.
Future studies should investigate a wider range of moderate caffeine doses. Testing your daily intake between 150 milligrams and 400 milligrams can help pinpoint the exact threshold at which anxiety symptoms begin to spike. Until then, choosing to enjoy a mild cup of coffee appears to pose little serious panic-inducing risk.
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 Björkstorm, Johan Vegelius, Lisa Klevebrant, Malin Gingnell, and Andreas Frick.
