Solipsism syndrome is a psychological state and condition in which a person feels that reality is not external to their mind.
In particular, the syndrome has been identified as a potential concern for individuals living in outer space for extended periods of time.
Individuals experiencing solipsism syndrome feel reality is not 'real' in the sense of being external to their own minds.
[citation needed] Periods of extended isolation may predispose people to solipsism syndrome.
In particular, the syndrome has been identified as a potential challenge for astronauts and cosmonauts on long-term missions,[3][4][5] and these concerns influence the design of artificial habitats.