The USS Abraham Lincoln, which has been participating in U.S. military operations in the war with Iran, is now on its way home. The roughly 5,000 sailors and Marines aboard that ship have spent a grueling nine months at sea with little relief.

Reports have emerged of deteriorating conditions — and of deteriorating mental health, including apparent attempts by crewmembers to jump overboard. The Navy has not confirmed those reports, and NPR has not independently verified them. “A small number of mental health cases were treated with no loss of life,” acting Secretary of the Navy Hung Cao said in a statement last week.

Experts say that while the physical circumstances are difficult, a lack of careful and consistent messaging from leadership at the highest levels also contributed to the crews’ mental distress.