Pay parity has been achieved for mental health and addiction workers, but many workers have already jumped ship.

The government has announced the workers will see a backdated pay rise, after being excluded from a settlement which saw a pay bump for care and support workers.

But Marion Blake, CEO of Platform Trust, which represents a range of mental health and addiction services, says it was easy for many to transfer their skills over to a higher paid job.

"Particularly in high stress areas like the Auckland area where there's a whole lot of other pressures across housing and across transport, that's where we were really seeing the push."