High numbers of Chinese Submariners Depressed

StrategyPage (which appears to recieve some US intel) March 22, 2021 reports :

Summary - In early 2021, 5 military medical researchers working for the Chinese Institute of Military Health Management published a report in the journal Military Medicine. This revealed 108 of 511 submariners taking a standard mental health assessment survey were suffering mental stress symptoms. This was due to their busy training schedule on PLA-N Chinese diesel-electric submarines operating in and near the South China Sea...

SEE MUCH MORE OF THIS STRATEGYPAGE ARTICLE 
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The Chinese PLA-N video above mainly shows the interior of  a Type 039A (Yuan class) sub. The helpful submariner guide at 0:56, next to the very cramped top bunk, is a Master Chief Petty Officer. Below video is such telling viewer comments, once translated:

“Salute to the submarine soldier, regardless of mental quality and environment are high pressure” 

and

“The psychological quality of these submarine soldiers is very strong, which is hard for ordinary people to imagine.”