Hector Sants, Britain's former top financial regulator who joined Barclays at the start of this year as head of compliance, is to take the rest of the year off after suffering from exhaustion and stress.
Barclays said that Sants had been diagnosed following five years at the helm of the Financial Services Authority and a busy start to his role at the bank.
The pressure on bankers, both junior and senior, has ratcheted up since the financial crisis due to job cuts, firesales and increased regulatory scrutiny.
Lloyds chief executive Antonio Horta-Osorio took two months off at the end of 2011 on doctors orders after suffering sleep deprivation and exhaustion while trying to turn the bank around.
He returned at the start of 2012 and has been praised for leading a recovery at Lloyds.
Sants is following medical advice and will be taking a leave of absence until the end of the year, Barclays said. He is expected to return to work in the new year.
Sants, who is head of compliance, government affairs and regulatory relations for the bank, sits on the executive committee and reports directly to chief executive Antony Jenkins. He is not a member of the bank's full board.