Humans will suffer "massive anxiety" if alien life is discovered.
An alien discovery will make humans panic
Experts believe that the human race isn't mentally ready for the shock of a close encounter and would end up questioning reality if the little green men were found.
Andreas Anton, of Germany's Institute for Frontier Areas of Psychology and Mental Health, said: "A biological life form could potentially cause great anxiety, as the immediate question would be what 'they' want here.
"It also has an assumption that they have a relatively nearby base or superfast travel and would thus be far ahead of us technologically."
The report backs up claims made by Dr. Malcolm Schofield, a psychology lecturer at Derby University, who suggested earlier this year that an alien discovery would have a transformative impact on society.
He said: "If something this big comes out it's going to make a lot of people question that concept of reality, and it is going to make them question their beliefs and society at large."