An Anxiety Disorder Secondary to Energy Drinks

Dear Editor:

In 2004, nearly $1 billion dollars were spent on energy drinks.¹ Excessive energy drink consumption may contribute patients presenting with anxiety symptoms.

Case Report. Mr. A was a 25-year-old man complaining of anxiety, restlessness, fidgetiness, irritability, difficulties concentrating, and problems falling asleep for a duration of four months. He denied any chronic medical issues. He took no prescription medications or over-the-counter medications. He denied any family psychiatric history. He had no history of trauma. Physical examination was unremarkable. Laboratory examination was unremarkable for a blood count, metabolic panel, liver function, thyroid function, and urine drug screen. The patient denied tobacco, alcohol, or coffee. He reported that he drank 6 to 8 8oz energy drinks daily for the previous four months. A calculation showed the patient consumed about 800mg per day of caffeine and 300mg daily of both ginseng and gingko biloba. The patient discontinued the drinks after the clinician educated him on their effects with complete resolution of symptoms. At three months the patient was doing well.

Discussion. Caffeine taken in amounts greater than 250mg per day can lead to physical symptoms including restlessness, nervousness, psychomotor agitation, tremulousness, and insomnia.³ This case highlights several points for clinicians evaluating patients with anxiety disorders. First to note is the widespread use of energy drinks by consumers. The drinks contain about 80mg of caffeine per 8oz drink. Some also contain guarana adding an additional 60mg of caffeine per drink. Additionally, these drinks contain the herbal substances ginseng and gingko biloba, which may elicit changes in a patient's thinking or behavior if taken regularly.³ It is important that providers consider energy drink consumption when evaluating for mood, anxiety, or sleep disorders.

With regards,
Tim Berigan, DDS, MD
Vail, Arizona