Seven school nurses taking part in the pilots in Perth and Kinross and Dumfries and Galloway decided to hand in their notice or retire after objecting to their new role.
The details emerged in an official report about the trials published by the Scottish Government, which wants to change the traditional way that school nurses operate.
Under the plans, nurses will take on new responsibilities previously carried out by social workers and mental health specialists, rather than focusing on treating sick pupils and doing vaccinations.
School nurses will be asked to focus on nine “priority areas” including children’s mental health and wellbeing, substance misuse, domestic abuse and the potential for them becoming homeless.
The report identified a number of issues with the new system, and said that many nurses did not feel equipped to deal with the number of children coming forward with mental health issues.
The majority of pupils (68 per cent) were referred to school nurses in the pilot areas due to concerns over their mental health and wellbeing, although the report said this may be due to it being a “catch-all” term.
Concerns were also raised about nurses becoming “less visible” in schools as they carry out other tasks, while training staff in the priority areas was described as “very time-consuming and stressful” for managers.
In Perth and Kinross, four of the original staff resigned or retired as a result of the new role, while in Dumfries and Galloway three newly hired staff all left before they could be properly trained.
A Scottish Government spokesman said: “These pioneering pilots showed that a targeted school nursing role added value to the service … We will now work with NHS boards to support them rolling out this refocused role.”