Medscape: “Patients who become caffeine-toxic may not even realize it.”
“Too often, patients presenting with complaints of some form of anxiety do not have a careful caffeine history taken. Caffeinated beverages, particularly strong ones, have become immensely popular in social situations and need to be asked about. Television shows popularize sitting in coffeehouses for long periods of time drinking coffee. Multiple new beverages have entered the market place with increasing amounts of caffeine. Virtually none of the media associated with all of this mentions anything about caffeine toxicity. As a result, patients who become caffeine-toxic may not even realize it. They may need to be educated that the amount of caffeine they are ingesting simply to be social is making them feel uncomfortable.”
Medscape: Dual Diagnoses, New Perspectives Link
British Journal of Addiction: 1 in 10 people caffeine-intoxicated
“Although infrequently diagnosed, caffeinism is thought to afflict as many as one person in ten of the population.”
JE James and KP Stirling, “Caffeine: A Summary of Some of the Known and Suspected Deleterious Habits of Habitual Use,” British Journal of Addiction, 1983;78:251-58. Link
British medical journal survey finds 40% of hospital inpatients caffeine-intoxicated
“[When caffeine is taken in excess], anxiety-related symptoms become increasingly apparent. A case of caffeinism, which presented as a paranoid delusion, is reported as an extreme example of this. A study of 60 hospital inpatients revealed that about 40% of them consumed sufficient caffeine to produce symptoms of caffeinism. It is thus recommended that all patients should be questioned on their caffeine intake. Also, caffeinism should be considered as a differential diagnosis of anxiety states.”
DC Mackay and JW Rollins, “Caffeine and caffeinism,” Journal of the Royal Naval Medical Service, 1989;75(2):65-7. Link
The Institute of Legal Medicine: “Coffee overindulgence is overlooked many times because the bizarre symptoms may resemble and masquerade as an organic or mental disease.”
“Coffee excesses can elicit symptoms of violent behavior in some persons; but what a feeling of relief to both physician and patient to see the symptoms completely disappear on the physician’s order to stop drinking coffee….”
“The symptoms vary with acquired or inborn tolerance, but in general the patients may complain of light headedness, dizziness, breathlessness, chest discomfort, nervousness, irritability, tremulousness, muscle twitching, tension headache, insomnia (difficulty in getting to sleep or staying asleep), psychoneurosis (anxiety), lack of appetite, loss of weight, restlessness, silliness, elation, euphoria, confusion, disorientation, excitation, and even violent behavior with wild, inanic screaming, kicking and biting, progressing to semi-stupor.”
“The symptoms of caffeine overdose are varied and bizarre and could be easily misinterpreted….Coffee overindulgence is overlooked many times because the bizarre symptoms may resemble and masquerade as an organic or mental disease.”
Sidney Kaye, PhD, of the Institute of Legal Medicine
Clinical nutritionist: Caffeinated persons are routinely “misdiagnosed as neurotic or even psychotic”
“In over a decade of practice as a clinical nutritionist, I have seen firsthand, with thousands of clients, that caffeine is a health hazard. Anxiety, muscle aches, PMS, headaches….However, if that’s all caffeine has done to you, you’re lucky. What about people misdiagnosed as neurotic or even psychotic, who spend years and small fortunes in psychotherapy–all because no one asked them about their caffeine intake?”
Nutritional biochemist Stephen Cherniske, in Caffeine Blues: Wake Up to the Dangers of America’s #1 Drug
Journal of the American Medical Association: Caffeine induces “psychological problems”
“The existence of a caffeine dependence syndrome, which includes evidence of continued caffeine consumption depite medical or psychological problems from caffeine consumption and unsuccessful efforts to quit caffeine use, provides a further similarity between caffeine and classic drugs of dependence.”
EC Strain, GK Mumford, K Silverman et al., “Caffeine Dependence Syndrome: Evidence from case histories and experimental evaluations.” Journal of the American Medical Association, 1995;273:1418-19. Link
Material Safety Data Sheet on caffeine exposure: Hallucinations, nervousness, psychosis
While the FDA labels caffeine as GRAS (”Generally Regarded As Safe”), chemical manufacturers are required by law to label caffeine “potentially fatal if inhaled, swallowed or absorbed through the skin” when handling and transporting it. Following is an excerpt from one Material Data Safety Sheet, courtesy of the University of California:
CAFFEINE:
TOXIC.
ACUTE EXPOSURE- Ingestion of large amounts may result in headache, lightheadedness, dizziness, chills, fever, excitement, restlessness, nervousness, insomnia, mild delirium, hallucinations, tinnitus, constricted pupils, decreased visual fields, amblyopia,diplopia, photophobia, and scintillating scotoma. Neurologic symptoms may persist for several days….Other effects may include alternating states of consciousness and muscle twitching, tremors, hyperesthesia, hypertonicity or hypotonicity, trismus, opisthotonus and convulsions. Seizures generally precede death.
CHRONIC EXPOSURE- In addition to the effects detailed in acute exposure, agitation, disturbed sleep, caffeine-induced psychosis, heartburn and hyperventilation may occur. Prolonged use of high doses may result in tolerence, physical and psychological dependence. Symptoms of withdrawal may occur following abrupt cessation.
Biochemist finds 50% of anxiety cases caffeine-induced
“If a person were injected with 500 milligrams of caffeine [less than the dosage recently discovered in some 16-ounce Starbucks brews], within about an hour he or she would exhibit symptoms of severe mental illness, among them hallucinations, paranoia, panic, mania, and depression. But the same amount of caffeine administered over the course of a day only produces the milder forms of insanity for which we take tranquilizers and antidepressants.”
“For five years I worked in a team practice with physicians and psychotherapists. Often, the psychological evaluation would include one or more anxiety syndromes, and the recommendation was for counseling. I would point out that the person was consuming excessive amounts of caffeine and request a trial month off caffeine prior to therapy sessions. In about 50% of cases, the anxiety syndrome would resolve with caffeine withdrawal alone.”
Nutritional biochemist Stephen Cherniske, Author, Caffeine Blues: Wake Up to the Dangers of America’s #1 Drug
“Too many clinical histories fail to record caffeine use.”
“Diagnosis of any caffeine-related disorder begins with clinical awareness. Beverage caffeine is such a common component of social activity that its consideration as a psychostimulant often is neglected.”
“Too many clinical histories fail to record caffeine use. A complete caffeine history includes doses associated with beverages and medications….The observable signs associated with caffeine consumption are dose dependent. For most individuals who consume caffeine in the average range, the physical stigmata will include arousal signs. Expect to see nervousness, elevated heart rate, increased respiratory rate, flushed face, and an exaggerated startle response. Caffeine is a mild diuretic and may contribute to vague gastrointestinal complaints. In rare cases where an individual’s dose exceeds 1 gram per day, the picture changes. Gross muscle tremors, highly disorganized speech, and possible arrhythmias herald a more sinister outcome.” [CaffeineWeb note: One gram has long been considered the toxic dose of caffeine, but it may not be as rare as supposed. A recent study published in the Journal of Analytical Toxicology found that two 16 oz. Starbucks coffees may contain in excess of one gram.]
R. Gregory Lande, DO, FACN, Deputy and Director of Professional Services, Department of Clinical Administration, William S. Hall Psychiatric Institute, University of South Carolina