Coffee is many people's legal drug of choice, kick-starting busy lives every morning. It is estimated that 1.6-billion cups of coffee are drunk worldwide everyday, according to the International Coffee Organisation, the main intergovernmental organisation for coffee.
Jonathan Robinson, founder of the South African coffee company, Bean There Fair Trade Coffee, said if he didn't get his first shot by 8am he would get a pounding headache.
The South African industry mainly sells instant coffee powder but the café culture of ground-bean coffee, although small, was growing rapidly, he said.
"We are legalised drug traders," he said and quipped that coffee should come with a warning that it "is addictive".
But it is more serious than that. Caffeine addiction and withdrawal have now been classified as formal mental disorders.
The latest edition of the Diagnostic and Statistical Manual of Mental Disorders, the bible of the American Psychiatric Association, has added "coffee withdrawal" and "caffeine intoxication" to its list of conditions. This means people in the United States can now be treated by their psychiatrist for drinking too much, or quitting too quickly. In the US, this also means some medical aids cover the treatment.
"Caffeine intoxication" is the first problem and comes when you drink more than three cups of coffee, or other caffeine-laden drinks, a day. Symptoms of this are restlessness, nervousness, twitching, gastrointestinal disturbance and rambling thought or speech.
Withdrawal occurs when people suddenly stop drinking their chosen caffeine drink and usually starts 12 hours after the last cup or glass.
The psychiatric association said coffee addiction was classified as a disorder because it negatively affected how people function in social and work situations. "Symptoms include headaches, fatigue, irritability, a depressed mood and difficulty concentrating," it said.
WeDoRecover, an international company that helps people with addictions, said on its website: "A simple to way to spot if you or someone you love is addicted to caffeine is to stop using it."
The biggest obstacle to treating caffeine addiction was people not seeing it as a real disorder so they did nothing, it said. The solution given by the association is to cut consumption to two cups a day.
If you don't, climate change could force you to go cold turkey. Research published in the journal PLoS ONE last month said the areas where arabica coffee beans are grown could become unsuitable for cultivation as global temperatures increase.
Beans and Bach It was probably people in Ethiopia who first discovered the energising effects of the wild coffee beans that grew in their highlands.
Ground down to powder, the drink became a part of their culture.
They exported the beans to the Arabian Peninsula in the 15th century and it caught on. The beans are now cultivated in 70 countries.
In Europe, coffee was associated with political dissent – those who drank it were said to be energised and active and coffee shops were to revolutions what Twitter is now.
In the 18th century, composer Johann Sebastian Bach wrote a symphony about coffee, Schweigt stille, plaudert nicht, also known as "the Coffee Cantata".
In the cantata, a father tries to convince his daughter to give up her copious consumption.
She refuses: "If I can't drink my bowl of coffee three times daily, then in my torment I will shrivel up like a piece of roast goat."