A study led by researchers at Uppsala University reported that playing the blockbuster video game Tetris following traumatic exposure significantly reduced flashbacks in patients with post-traumatic stress disorder.

164 healthcare workers in Sweden were recruited and led by Professor Emily Holmes in a controlled experiment to assess whether a Tetris-based intervention reduces symptoms of PTSD.

The study from September 2020 through April 2022 indicated that the participants exposed to Tetris had the average of flashbacks diminished very sharply.

At the five-week follow-up, people in the Tetris group reported an average of only one flashback per week; in contrast, in the control group, where individuals listened to the radio alone, the average of flashbacks was five. After six months of the treatment, Tetris players kept on reporting half the average flashbacks as the control group.

This is based on work Holmes conducted back in 2009. He basically suggested that Tetris counters "dysfunctional mental imagery" by demanding the working of the visuospatial memory in the brain, an area that would be also used in developing intrusive memory.

The challenge to spatial reasoning tasks shares the mental resources, weakening the intensity and frequency of flashbacks.

Holmes sees Tetris becoming a kind of "cognitive vaccine" that blocks the early signs of PTSD, intrusion, in the very frontline staff who deal directly with them.

Results from a study published in BMC Medicine show that 20 minutes of this game can prolong therapeutic effect.