Psychological tests were undertaken on the eight wintering members of the 28th Japanese Antarctic Research Expedition (mean age 35±SD 4years old) with about 4 month intervals through the expedition.
The first test was done on the ship to Antarctica on November 24, 1986 (Test-1), and the second (Test-2), the third (Test-3) and the fourth test (Test-4) were done at the Japanese Antarctic Asuka Base on March 28, 1987, July 17, 1987 and October 11, 1987, respectively. The last fifth test (Test-5) was performed on the ship to Japan on February 29, 1988.
For psychological tests, MAS (manifest anxiety scale), CMI (Cornell Medical Index) and SRQ-D (Self-rating Questionaire for Depression) were used.
The mean scores of MAS-A, CMI-T (S, I, J+M-R) showed a tendency to become high in Test-2 and Test-3 and become low after Test-4. The mean scores of SRQ-D exhibited a tendency to become high in Test-3 and the high score continued after Test-4.
The psychological stress seems to have reached a peak point at Test-3, in July, 1987, when was the last session of winter with no sunshine at Antarctic Base.
Some management for mental health might be needed in this season for the wintering members of the Japanese Antarctic Research Expedition.