Adored by teenagers, loathed by anyone over 40. An estimated 93 million selfies were posted online last year with 91% of teenagers posting at least one.

Widely criticised if not demonised, selfies are associated with all sorts of problems. Last year more people died while taking one than from shark attacks - because of falls, traffic accidents and more. Mental issues are lurking in the background: in 2014 a study from Ohio State University found that men who posted the most selfies on social media scored highest on questionnaires for narcissistic and psychopathic traits. Researchers branded the habit as addictive, some claiming that spending more than five minutes on a selfie or taking more than three to five a day may be “considered a disease”. Many believed a hoax report claimed that selfie taking was a new mental health problem defined by the American Psychiatric Association as “the obsessive compulsive desire to take photos of one’s self and post them on social media”.

But a small study demonstrated that taking three selfie a day while smiling to the camera and looking at them afterwards can improve your mood, restoring some degree of self confidence. After all, smiling is a therapy in itself.

As scientists usually say, there is the need for more research on the field. But a selfie a day could be your tool for a better day.