Behavioral health & cognition

NASA risk title (verbatim)

Risk of Adverse Cognitive or Behavioral Changes and Psychiatric Disorders Leading to In-mission Health and Performance and Long-term Health Effects

NASA short title: Behavioral Health · HRP element: Human Factors and Behavioral Performance (HFBP) · Status: Active [current research ongoing] [1]

What it is

This risk covers changes in mood, behavior and thinking (cognition), up to psychiatric disorders, that could affect a crew member during a mission or for years afterward [1]. It now also covers the brain effects of space radiation. NASA folded the former separate radiation central nervous system risk into this one [1].

Current evidence

• Mild (sub-diagnostic) behavioral health problems have been reported on several long missions. No in-flight case has reached a diagnostic threshold, even though some were linked to lost mission objectives or an early return [1].
• NASA estimates behavioral health symptoms on the International Space Station (ISS) at about 0.62 per person-year and says this is likely an underestimate [1].
• In Antarctic stations, at least 4.5% of people develop a psychiatric disorder [1]. A Lancet review put the figure at about 5% of polar expedition members meeting DSM-IV or ICD criteria [4].
• Analog studies suggest symptoms may rise faster after about 5–6 months (preliminary) [1]. In the 520-day Mars-500 simulation, the six crew members responded very differently from one another [5].
• MRI shows brain position and shape changes after long flights. Narrowing of the central sulcus was seen in 17 of 18 long-duration astronauts versus 3 of 16 short-duration astronauts [6]. What this means for thinking or long-term health is unknown [1].
• Cognitive studies in flight are small: a 2014 review found 11 long-duration studies totaling 42 people. The evidence neither strongly supports nor rules out specific deficits [7]. Animal work suggests radiation might cause short-term cognitive effects, but how well this applies to humans is uncertain [1].

NASA’s risk posture

NASA scores each risk for each design reference mission (DRM) as likelihood × consequence (LxC). Both run from 1 (lowest) to 5 (highest) on the HSRB’s 5×5 matrix [1][3]. Each score comes with a disposition, such as “Accepted”, “Requires Characterization” or “Requires Mitigation”. These ratings were last approved by NASA’s Human System Risk Board (HSRB) in 7/2024 [1].

Copied from the Human Research Roadmap on 2026-10-14. Ratings change. Check the live record before citing.

Open knowledge gaps

NASA lists 8 knowledge gaps for this risk, 8 of them open as of 2026-10-14 [1]. Each gap ID links to its page on the Human Research Roadmap (HRR).

See also Open questions.

Active countermeasure research

• Monitoring and early detection. NASA is developing ways to monitor cognitive and behavioral health during long missions and to detect early warning signs [1].
• Countermeasures. NASA is developing ways to maintain behavioral health in isolated, confined and highly autonomous missions. These are tested in ground analogs before flight [1].
• An integrated approach. NASA’s research plan treats three stressors together because they are thought to interact: space radiation, isolation and confinement, and altered gravity [1].

Project-level detail, including status, investigators and results, is in the NASA Task Book and on each HRR gap page.

Clinical articles

For practical, clinic-facing guidance, see:

• Behavioral Health, Sleep & Cognition: Monitoring and Support Before, During and After Flight