The claim that “one in four” of us will suffer from a mental health problem is popular amongst campaigners, politicians and the media. But where is this figure from and what’s the evidence for it?

A paranoid conspiracy theory questioning the reality of the shooting dead of 26 people at Sandy Hook Elementary School in 2012 has acquired a new, disturbing power in America. Rumours that the killings were staged by actors have been pushed by alternative media mogul Alex Jones. His online news site Infowars has millions of listeners and viewers. One grieving father, Lenny Pozner, tells how he has led the online fightback.

Also, from ancient Greece to Instagram – has the six-pack become the ultimate sign of success for today’s young man?

(Photo: Commuters pass through Grand Central Terminal during morning rush hour Credit: Getty Images)