Sad people are better at facial recognition than their happier counterparts, scientists have found.
Researcher Peter Hills, from Anglia Ruskin University, said his findings could lead to better treatments for depression.
"I was surprised. Sad mood is usually associated with poorer performance in cognitive tasks," the Daily Mail quoted him as telling Live Science.
Dr Hills and his team at the university, which is based in Cambridge and Chelmsford, played three pieces of music to get volunteers in one of three moods - sad, happy or neutral.
Mozart's Requiem was played for sadness; the jaunty theme from 1980s TV show The A-Team for happiness; and the theme from the 1990 film The Hunt For Red October for a neutral mood.
Depending on which group they were in, the volunteers were then asked to think of either the saddest or happiest moments in their lives, or their journey home if they were neutral.
The 88 volunteers - all students - were then asked to look at 32 faces with neutral expressions.
After completing a brief questionnaire as a distraction, they were then shown 64 faces and asked to pick out the original 32.
The sad volunteers gave the most accurate response, while the happy students were the least accurate.
"It is possible that sad people may be more susceptible to social cues," Dr Hills added.
The study has been published in the journal Consciousness and Cognition.