“Caffeine intoxication” became official in the medical community when the “Diagnostic and Statistical Manual of Mental Disorders,” known as DSM-5, added the diagnosis last year.So do cappuccino lovers need to worry about limiting their consumption?
One expert, Matthew Johnson, associate professor in the department of psychiatry at Johns Hopkins University, explains how caffeine works in the body and when to cut back.
Caffeine works by blocking adenosine, a neuromodulator in the brain that puts the brakes on excitatory neurotransmitters like dopamine and norepinephrine. “Caffeine allows these stimulating chemicals to flow, which can have a rousing effect, even at very low doses,” says Dr. Johnson, a psychopharmacologist who studies the influence of drugs on behavior and mood.Some people will get edgy from a weak cup of tea. For others, a double espresso is required to get them into the shower in the morning.
Most coffee drinkers are familiar with at least some symptoms of overindulging—nervousness, excitement, insomnia, rambling thoughts. But a large majority of people who consume caffeine don’t experience severe consequences, Dr. Johnson says.There are some case reports of students experiencing major anxiety after drinking a dozen cups of coffee, Dr. Johnson says. But overdosing would be difficult, “unless folks took multiple caffeine pills or drank many cans of energy drinks” such as Red Bull.
It is possible for a person to die from too much caffeine, “but that would mean about 14,000 milligrams, or around 140 8-ounce cups of coffee in one day,” Dr. Johnson says. Consuming that much would be difficult because of coffee’s self-limiting nature. “One cup makes you feel good and alert, but five cups may make you feel like your stomach is cramping,” he says. “You feel wired and you wouldn’t typically be able to go overboard.”