Playing the 1980s computer game Tetris, can prevent the unpleasant flashbacks which come after a traumatic event, scientists have discovered.

Oxford University and the Karolinska Institute in Sweden found that patients treated in accident and emergency departments following car accidents were far less likely to develop post-traumatic stress disorder (PTSD) if they were allowed to play the game within six hours of admission.

The puzzle, which involves fitting brightly-coloured blocks together is one of the most popular video games ever invented, and is still played by millions of people around the world.

PTSD can affect people who have experienced war, torture, rape, road accidents or other kinds of situations in which they felt their life, or that of another person, was in danger.

While most people do not develop PTSD after trauma, one of the core clinical symptoms in those who do involves recurrent and intrusive memories, or flashbacks.