Consistent with a half-life of caffeine of approximately 4—6 hours, caffeine intoxication symptoms usually remit within the first day or so and do not have any known long-lasting consequences. However, individuals who consume very high doses of caffeine (i.e., 5—10 g) may require immediate medical attention, as such doses can be lethal.
With advancing age, individuals are likely to demonstrate increasingly intense reac- tions to caffeine, with greater complaints of interference with sleep or feelings of hyper- arousal. Caffeine intoxication among young individuals after consumption of highly caffeinated products, including energy drinks, has been observed. Children and adoles- cents may be at increased risk for caffeine intoxication because of low body weight, lack of tolerance, and lack of knowledge about the pharmacological effects of caffeine.
Environmental. Caffeine intoxication is often seen among individuals who use caffeine tial amount. Furthermore, oral contraceptives significantly decrease the elimination of caf— feine and consequently may increase the risk of intoxication.
Genetic and physiological. Genetic factors may affect risk of caffeine intoxication.
Functional Consequences of Caffeine Intoxication
Impairment from caffeine intoxication may have serious consequences, including dys- function at work or school, social indiscretions, or failure to fulfill role obligations. More- over, extremely high doses of caffeine can be fatal. In some cases, caffeine intoxication may precipitate a caffeine-induced disorder.
Other mental disorders. Caffeine intoxication may be characterized by symptoms (e.g., panic attacks) that resemble primary mental disorders. To meet criteria for caffeine intoxica- tion, the symptoms must not be associated with another medical condition or another mental disorder, such as an anxiety disorder, that could better explain them. Manic episodes; panic disorder; generalized anxiety disorder; amphetamine intoxication; sedative, hypnotic, or anx- fects (e.g., akathisia) can cause a clinical picture that is similar to that of caffeine intoxication.
Other caffeine—induced disorders. The temporal relationship of the symptoms to increased caffeine use or to abstinence from caffeine helps to establish the diagnosis. Caffeine intoxica- tion is differentiated from caffeine-induced anxiety disorder, with onset during intoxication (see ”Substance/Medication-Induced Anxiety Disorder” in the chapter ”Anxiety Disorders”), and caffeine—induced sleep disorder, with onset during intoxication (see ”Substance/Medica- tion—Induced Sleep Disorder” in the chapter ”Sleep-Wake Disorders”), by the fact that the symptoms in these latter disorders are in excess of those usually associated with caffeine in- toxication and are severe enough to warrant independent clinical attention.
Typical dietary doses of caffeine have not been consistently associated with medical prob- lems. However, heavy use (e.g., >400 mg) can cause or exacerbate anxiety and somatic symptoms and gastrointestinal distress. With acute, extremely high doses of caffeine, grand mal seizures and respiratory failure may result in death. Excessive caffeine use is as- sociated with depressive disorders, bipolar disorders, eating disorders, psychotic disor- ders, sleep disorders, and substance-related disorders, whereas individuals with anxiety disorders are more likely to avoid caffeine.
Diagnostic Criteria 292.0 (F15.93)
A. Prolonged daily use of caffeine.
B. Abrupt cessation of or reduction in caffeine use, followed within 24 hours by three (or more) of the following signs or symptoms:
Headache.
Marked fatigue or drowsiness.
Dysphoric mood. depressed mood, or irritability.
Difficulty concentrating.