In December, I read an article which reviewed a study in Progress in Neuro-Psychopharmacology & Biological Psychiatry using 668 students from the University of Barcelona, in which the study found that caffeine is more effective in men than in women, with effects lasting from two to three hours.

The effects of caffeine (increased alertness, improved mood) effectively start in as few as 10 minutes (depending on whether or not other food is ingested at the same time) and reach maximum effect at 30 to 45 minutes.

Today I read a different article discussing a study funded by the Economic and Social Research Council and the Medical Research Council (UK). The study described the effect three cups of brewed coffee (or the equivalent caffeine in other drinks) on psychologically healthy subjects: they were more likely to hallucinate.

Those who experienced hallucinations saw things that were not there; they heard voices; they reported sensing the presence of dead people.

Hmmm....