The caffeine withdrawal syndrome has been well-characterized in numerous rigorous double-blind studies. The potential for caffeine withdrawal to cause clinically significant distress or impairment in functioning is reflected by the inclusion of caffeine withdrawal as an official diagnosis in ICD-10 (World Health Organization) and as a proposed diagnosis in DSM-IV (American Psychiatric Association). Although most research on withdrawal has been performed with adults, there is also evidence that children experience withdrawal effects during caffeine abstinence. Signs and symptoms.
The most commonly reported withdrawal symptoms are listed below:
- Headache – (often described as being gradual in development and diffuse, and sometimes throbbing and severe)
- Fatigue — (e.g., fatigue, tiredness, lethargy, sluggishness)
- Sleepiness/drowsiness — (e.g., sleepy, drowsy, yawning)
- Difficulty concentrating — (e.g., muzzy)
- Work difficulty — (e.g., decreased motivation for tasks/work)
- Irritability — (e.g., irritable, cross, miserable, decreased well-being/contentedness)
- Depression — (e.g., depressed mood)
- Anxiety — (e.g., anxious, nervous)
- Flu-like symptoms — (e.g., nausea/vomiting, muscle aches/stiffness, hot and cold spells, heavy feelings in arms or legs)
- Impairment in psychomotor, vigilance and cognitive performances
The incidence and severity of caffeine withdrawal is an increasing function of daily self-reported caffeine dose. Significant caffeine withdrawal has been shown to occur after abstinence from a dose as low as 100 mg/day, which is the caffeine equivalent of one 6 oz. cup of brewed coffee or two to three 12 oz. servings of caffeinated soft-drink. Caffeine withdrawal has also been shown to occur after stopping regular once-a-day consumption of caffeine (e.g. daily consumption of a single cup of coffee).