People who rely on a morning coffee to get them going may simply be tricking themselves.
According to recent research from a team at Bristol University, the traditional quality of alertness associated with coffee may just be an illusion.
The study, which was published in Neuropsychopharmacology, looked at a group of 379 individuals after they had been denied caffeine for 16 hours.
Splitting the volunteers in to two groups, the researchers gave one section caffeine, while the other half was given a placebo substance.
They were then tested for a range of responses but little difference was seen between the two.
Peter Rogers, one of the lead authors of the study, commented: "Our study shows that we don't gain an advantage from consuming caffeine - although we feel alerted by it, this is caffeine just bringing us back to normal.
"On the other hand, while caffeine can increase anxiety, tolerance means that for most caffeine consumers this effect is negligible."