People caught up in a nuclear disaster are more likely to suffer severe psychological disorders such as depression and post-traumatic stress disorder rather than harm from radiation, scientists said Friday.

Factors such as having to evacuate their home or simple fear itself contribute to the trauma, the scientists said in studies published in The Lancet to mark the 70th anniversary of the U.S. atomic bombing of Hiroshima and Nagasaki.

The studies counter the misconception that nuclear disasters have caused widespread death and physical illness, with the researchers finding that the mental health effects were far more profound.