England wicketkeeper Sarah Taylor will miss the Women's World Twenty20 in the Caribbean as part of the ongoing management of her anxiety.
The 29-year-old took a break from the game in 2016 but returned to play in England's World Cup win of 2017.
The decision to miss the tournament has been taken "mutually" by Taylor and England management staff.
England will name their squad next Thursday, with the competition beginning on 9 November.
England coach Mark Robinson said: "Since the end of the summer Sarah hasn't been able to train fully with the squad due to not being as fit as she would want to be from a psychological point of view.
"At the moment she isn't in a place where we would all be comfortable that the demanding training, playing and travel schedule wouldn't potentially put her backwards and make her road to full recovery longer."
Since returning before the World Cup, Taylor has toured Australia for the Ashes at the end of 2017, but missed the trip to India in the early part of 2018.
She was part of the Surrey Stars side that won the domestic Super League during the home summer.
"It's important we see mental health in a similar way to a player with a physical injury," added Robinson.
"You wouldn't risk a player if you felt that playing them with an injury would increase the chances of them being out for a long time or the issue even becoming career-threatening.
"Sarah will continue to train at Loughborough at a pace more suited to where she is right now with a view to hopefully being fully fit in the new year."
England won the inaugural Women's World T20 in 2009 and were beaten finalists in both 2012 and 2014.
The 2018 edition of the tournament will be the first time that the women's is a standalone, not tied to a men's competition.
England are in Group A, alongside South Africa, Sri Lanka, Bangladesh and defending champions West Indies.