Additional information on caffeine-related disorders
Additional Information on Caffeine-Related Disorders
Associated Features and Disorders
Mild sensory disturbances (e.g., ringing in the ears and flashes of light) have been reported at higher doses. Although large doses of caffeine can increase heart rate, smaller doses can slow the pulse. Whether excess caffeine intake can cause headaches is unclear. On physical examination, agitation, restlessness, sweating, tachycardia, flushed face, and increased bowel motility may be seen. Typical patterns of caffeine intake have not been consistently associated with other medical problems. However, heavy use is associated with the development or exacerbation of anxiety and somatic symptoms such as cardiac arrhythmias and gastrointestinal pain or diarrhea. With acute doses exceeding 10 g of caffeine, grand mal seizures and respiratory failure may result in death. Excessive caffeine use is associated with Mood, Eating, Psychotic, Sleep, and Substance-Related Disorders, whereas individuals with Anxiety Disorders are likely to avoid this substance.
Specific Culture, Age, and Gender Features
Caffeine use and the sources from which caffeine is consumed vary widely across cultures. The average caffeine intake in most of the developing world is less than 50 mg/day, compared to as much as 400 mg/day or more in Sweden, the United Kingdom, and other European nations. Caffeine consumption increases during the 20s and often decreases after age 65 years. Intake is greater in males than in females. With advancing age, people are likely to demonstrate increasingly intense reactions to caffeine, with greater complaints of interference with sleep or feelings of hyperarousal.
Prevalence
The pattern of caffeine use fluctuates during life, with 80%-85% of adults consuming caffeine in any given year. Among people who consume caffeine, 85% or more use a caffeine-containing beverage at least once a week, imbibing an average of almost 200 mg/day. Caffeine intake is probably elevated among individuals who smoke, and perhaps among those who use alcohol and other substances. The prevalence of Caffeine-Related Disorders is unknown.
Course
Caffeine intake usually begins in the mid-teens, with increasing levels of consumption through the 20s into the 30s, when use levels off and perhaps begins to fall. Among the approximately 40% of individuals who have stopped the intake of some form of caffeine, most report that they changed their pattern in response to its side effects or health concerns. The latter include cardiac arrhythmias, other heart problems, high blood pressure, fibrocystic disease of the breast, insomnia, or anxiety. Because tolerance to the behavioral effects of caffeine does occur, Caffeine Intoxication is often seen in those who use caffeine less frequently or in those who have recently increased their caffeine intake by a substantial amount.
Differential Diagnosis
For a general discussion of the differential diagnosis of Substance-Related Disorders, see p. 207. Caffeine-Induced Disorders may be characterized by symptoms (e.g., Panic Attacks) that resemble primary mental disorders (e.g., Panic Disorder versus Caffeine-Induced Anxiety Disorder, With Panic Attacks, With Onset During Intoxication). See p. 210 for a discussion of this differential diagnosis.
To meet criteria for Caffeine Intoxication, the symptoms must not be due to a general 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 Anxiolytic Withdrawal or Nicotine Withdrawal, Sleep Disorders, and medication-induced side effects (e.g., akathisia) can cause a clinical picture that is similar to that of Caffeine Intoxication. The temporal relationship of the symptoms to increased caffeine use or to abstinence from caffeine helps to establish the diagnosis. Caffeine Intoxication is differentiated from Caffeine-Induced Anxiety Disorder, With Onset During Intoxication (p. 479), and from Caffeine-Induced Sleep Disorder, With Onset During Intoxication (p. 655), by the fact that the symptoms in these latter disorders are in excess of those usually associated with Caffeine Intoxication and are severe enough to warrant independent clinical attention.