Editing Human spaceflight (section)

===== Isolation =====
{{Further|Effect of spaceflight on the human body#Psychological effects|Psychological and sociological effects of spaceflight}}

During long missions, astronauts are isolated and confined in small spaces. [[Depression (mood)|Depression]], anxiety, [[cabin fever]], and other psychological problems may occur more than for an average person and could impact the crew's safety and mission success.<ref>{{Cite journal|last=Flynn|first=Christopher F.|date=1 June 2005|title=An Operational Approach to Long-Duration Mission Behavioral Health and Performance Factors|url=http://www.ingentaconnect.com/contentone/asma/asem/2005/00000076/A00106s1/art00007|journal=Aviation, Space, and Environmental Medicine|volume=76|issue=6|pages=B42–B51|pmid=15943194}}</ref> NASA spends millions of dollars on psychological treatments for astronauts and former astronauts.<ref>{{Cite book |title=Space psychology and psychiatry |date=2008 |publisher=Springer |last1=Kanas |first1=Nick |last2=Manzey |first2=Dietrich |isbn=9781402067709 |edition=2nd |location=Dordrecht |oclc=233972618}}</ref> To date, there is no way to prevent or reduce mental problems caused by extended periods of stay in space.

Due to these mental disorders, the efficiency of astronauts' work is impaired; and sometimes they are brought back to Earth, incurring the expense of their mission being aborted.<ref>{{Cite news |url=https://www.theguardian.com/science/2014/oct/05/hallucinations-isolation-astronauts-mental-health-space-missions|title=Isolation and hallucinations: the mental health challenges faced by astronauts |last=Bell|first=Vaughan|date=5 October 2014|work=The Observer|access-date=2019-02-01|language=en-GB |issn=0029-7712}}</ref> A Russian expedition to space in 1976 was returned to Earth after the cosmonauts reported a strong odor that resulted in a fear of fluid leakage; but after a thorough investigation, it became clear that there was no leakage or technical malfunction. It was concluded by NASA that the cosmonauts most likely had [[Phantosmia|hallucinated the smell]].

It is possible that the mental health of astronauts can be affected by the changes in the sensory systems while in prolonged space travel.