Barnet, Enfield and Haringey Mental Health trust has seen several senior staff leave ahead of a reorganisation of its executive board as it prepares for its application to become a foundation trust.
Last week the trust's nursing director Bernadette Hennigan left by 'mutual agreement' after three years.
This month the organisation's human resources director Janet Lynch will also be departing to become the new HR director at East and North Hertfordshire trust.
Ms Hennigan has been replaced by interim nursing director Paul Farrimond, from North Yorkshire and York primary care trust.
The trust has not yet appointed a new HR director.
In July former trust chief executive John Newbury-Helps also left the organisation and has been replaced by Martin Brown as interim chief executive.
Mr Brown, who is an associate director at consultancy firm Mental Health Strategies and former head of health at the Audit Commission, will remain in post for six months until December.
By then the trust hopes to have appointed a permanent chief executive.
Barnet, Enfield and Haringey Mental Health trust is also recruiting a new medical director following Rosalind Furlong's announcement that she will retire at the end of the year.
HSJ understands that a number of internal candidates had applied for the position but that the trust has not appointed and will be advertising the post externally.
A spokesman for the trust told HSJ that the various executive board member departures were being used as an opportunity to review the posts and the board leading up to foundation trust application.
'As with any organisation people leave for a range of reasons.
'We are using this as an opportunity to review posts as we journey to foundation trust status,' he said.