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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

Renowned allergist: Thousands are in mental institutions because of caffeine

“Thousands are in mental institutions today because of no greater matter than that of the use of caffeine. Psychiatrists are now publishing articles indicating that there are numerous cases of depression and anxiety in mental institutions who need no other treatment than to be taken off caffeine. It would seem that with such a simple remedy available, many thousands of people could be returned to their full usefulness promptly.

“However, the use of caffeine is so traditional and firmly entrenched that it is almost impossible to remove caffeinated drinks from the diet of patients in the mental institutions. Soft drink machines, coffee dispensers, and the traditional coffee break are common pastimes in mental institutions, and with those who are mentally ill at home.”

Calvin Thrash.jpg

Calvin Thrash, M.D., Author, Food Allergies Made Simple

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

Johns Hopkins University School of Medicine: Patients may fail to recognize caffeine-induced symptoms

“The potential for caffeine intoxication to cause clinically significant distress is reflected by the inclusion of caffeine intoxication as a diagnosis in DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition)(American Psychiatric Association, 1994) and in ICD-10 (International Statistical Classification of Diseases and Related Health Problems, Tenth Edition)(World Health Organization).”

“Studies have shown that high dietary doses of caffeine (200 mg or more) increase anxiety ratings and induce panic attacks in the general population. In the United States the average per capita daily intake among adult caffeine consumers is 280 milligrams (the equivalent of 17 ounces of brewed coffee).”

“Although highly anxious individuals tend to be more likely to limit their caffeine use, not all individuals with anxiety problems naturally avoid caffeine, and some may fail to recognize the role that caffeine is playing in their anxiety symptoms.”

“It has been noted that caffeine intoxication can occur in someone who has been using caffeine for many years with no prior apparent problems.”


Roland R. Griffiths, Ph.D, The Johns Hopkins University School of Medicine
Professor of Behavioral Biology, Department of Psychiatry & Behavioral Sciences
Professor of Neuroscience, Department of Neuroscience

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

DSM-IV on “Caffeine-Induced Psychiatric Disorders”

“The 4 caffeine-induced psychiatric disorders include caffeine intoxication, caffeine-induced anxiety disorder, caffeine-induced sleep disorder, and caffeine-related disorder not otherwise specified (NOS).”


Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) Link

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


Psychiatrists: “Psychosis can be induced in normal individuals ingesting caffeine at toxic doses.”

“Psychosis can be induced in normal individuals ingesting caffeine at toxic doses, and psychotic symptoms can also be worsened in schizophrenic patients using caffeine….Prevention of caffeine-induced psychiatric symptoms is possible by recognizing, educating, and treating patients using a tapering approach.”

Broderick P, Benjamin AB, Caffeine and psychiatric symptoms: A Review; J Okla State Medical Assoc, 2004 Dec; 97(12):538-42

Caffeine expert: Caffeine produces anxiety, psychotic states, toxic dementia

“An allergic reaction to caffeine manifests as anaphylaxis. During a state of caffeine anaphylaxis, the body enters the fight or flight mode, which may be mistaken as hyperactivity, anxiety, or panic disorder. Caffeine anaphylaxis causes cerebral vasculitis, leads to the breakdown of the blood brain barrier, and generates toxic dementia.”

“Symptoms range from minimal reactions to severe psychotic states, which may include irrational behavior, disruptions in attention, lack of focus and comprehension, mood changes, lack of organizational skills, abrupt shifting of activities, delusions, hallucinations, and paranoia.”

“An allergic reaction to caffeine results in poisoning of the prefrontal cortex. Damage to the underside area on the prefrontal cortex, above the eye sockets, generally renders a person absent minded and interferes with the ability to monitor personal activities (Carter, 1998). Injury results in loss of verbal and social inhibition….”

“While others may notice menacing changes in behavior or personality changes, the victim may not.”

Ruth Whalen, MLT

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:

  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.

University of California Material Safety Data Sheet

Eminent pharmacologist: Caffeine causes depression

“There is no doubt that the excitation of the central nervous system produced by large amounts of caffeine is followed by depression.”

J. Murdoch Ritchie, Professor Emeritus, Department of Pharmacology, Yale University School of Medicine, in The Pharmacological Basis of Therapeutics, Goodman and Gilman eds.


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

Journal of Orthomolecular Psychiatry: Caffeine-induced psychosis may be mistaken for true psychosis

“Recently published studies and reports of personal observations have shown without doubt that caffeine abuse (caffeinism) may result in a syndrome which resembles and may be confused or confounded with true psychotic states. This may lead to misdiagnosis and mistreatment. A question arises from the varied reports of caffeine consumption in psychiatric populations: Does caffeine stimulate psychosis or does psychosis stimulate caffeine consumption?”

Sanford Bolton, PhD and Gary Null, M.S., Journal of Orthomolecular Psychiatry Link

The New England Journal of Medicine: Patient’s mania a result of caffeine intake

Psychiatrists’ initial verdict on one caffeine-poisoned patient, in a case cited by Dr. Edward M. Brecher in the landmark “Consumers Union Report on Licit and Illicit Drugs”:

“Hysteria without question. When she failed to improve and remained wildly manic for several days, she was transferred to a psychiatric hospital, where she was at first kept tied to a bed. After almost two months in the hospital, during which she slowly recovered, a mild relapse occurred. Investigation showed that she was drinking coffee, four cups a day. At this point, suspicion for the first time turned to caffeine. Coffee and tea were removed from her vicinity and soon she again became entirely normal, and was dismissed from the hospital.”


MC McManamy and PG Schube, “Caffeine Intoxication: Report of a Case the Symptoms of which Amounted to a Psychosis,” New England Journal of Medicine, 1936;215:616-620. Link

Journal of Affective Disorders: Woman’s bipolar disorder vanishes as caffeine intake is discontinued

“A longitudinal case report shows a sudden remission of the severe course of a seasonal bipolar disorder after 10 years of psychopharmacological treatments. The discontinuation of heavy caffeine intake appears to have contributed to the outcome.”


Abstract of: L Tondo and N Rudas, “The course of a seasonal bipolar disorder influenced by caffeine,” Journal of Affective Disorders, 1991;22 (4):249-251 Link

NASA’s Caffeine Findings


In 1995, NASA’s Dr. David Noever and his fellow researchers at the Marshall Space Flight Center studied the webs spun by common house spiders (Araneus diadematus) dosed with several drugs, including LSD, marijuana, benzedrine, chloral hydrate and caffeine. The more toxic the drug, the less organized the web the spider created.

The spider on marijuana drifted off before finishing the job. The spider on benzedrine, an upper, worked energetically but without much planning. The spider dosed with chloral hydrate, a sedative, soon fell asleep.

To the surprise of Dr. Noever et al, caffeine did the most damage of all the substances tested. The spider dosed with it proved incapable of creating even a single organized cell, and its web showed no sign of the “hub and spokes” pattern fundamental to conventional web design.

What does the web of a caffeinated spider (which can hardly be accustomed to the jolt of a morning latte) have to do with human behavior? Unlikely as it sounds, it may be the most vivid illustration of caffeine’s disorienting effect on caffeine-sensitive people, many of whom may be misdiagnosed as mentally ill:

“Caffeine-induced psychosis, whether it be delirium, manic depression, schizophrenia, or merely an anxiety syndrome, in most cases will be hard to differentiate from other organic or non-organic psychoses….The treatment for caffeine-induced psychosis is to withhold further caffeine.”

Clinical Management of Poisoning and Drug Overdose, 3rd ed., 1998
Michael W. Shannon, MD, MPH,
Director, Lead and Toxicology Clinic, The Children’s Hospital; Associate Professor of Pediatrics, Harvard Medical School; Staff Toxicologist, Massachusetts Poison Control System; Lester M. Haddad, MD, Clinical Professor in Family Medicine, Medical University of South Carolina; Emergency Physician and Active Staff, Bon Secours St. Francis Xavier Hospital; James F. Winchester, MD, Professor of Medicine, Division of Nephrology, Georgetown University Medical Center

Important: The information on this web site is not a substitute for an informed discussion with a health care professional. In certain cases caffeine is the primary cause of symptoms that mimic mental illness, which vanish when caffeine is eliminated from the system. But caffeine is also known to exacerbate preexisting mental disorders, in which case withdrawing from caffeine is only one ingredient to improving your health. If you have been diagnosed with one of the illnesses caffeinism mimics, be sure to consult your doctor before acting on the information at CaffeineWeb.com.