If you think coffee helps you sober up after drinking a little too much, think again. Caffeine probably makes it worse, new research has discovered. A cup of coffee may make it harder to realise that you are drunk, say researchers. As a result, you may attempt something dangerous, such as driving, whereas someone who hadn't had the coffee might be more aware of his or her limitations. The study, carried out by Temple University in Philadelphia, is also bad news for the caffeine-enhanced energy drinks that also contain some alcohol. Sales of the drinks have sky-rocketed in recent years, but Thomas Gould at the university warns that they produce deficits in general cognitive ability. (Source: Behavioural Neuroscience, 2009; 123: 6).