A mental health nurse crossed the line after contacting a schoolboy they were treating on social media and sending him messages of a "personal nature".

The nurse met the vulnerable teenager after he was referred to the mental health service by his school counsellor.

He spent eight months under the nurse's care with treatments including face-to-face intervention, psycho-education, co-ordination of services, including referral to a private psychologist, and ongoing risk assessment.

However, during the therapeutic relationship, the nurse failed to maintain professional and ethical boundaries by contacting the young man on social media, Deputy Health and Disability Commissioner Dr Vanessa Caldwell found in a report released today.

One of those inappropriate personal messages included a request to send a selfie.

In other messages the nurse commented about what the boy was wearing and said "Ooo would like to [see you] running now if [you're] just in shorts lol," with another "smirking face" emoticon after the boy stated he might go for a run.

The actions were considered to have flouted the established standards and breached the Code of Health and Disability Services Consumers' Rights.

As a healthcare provider, the services provided by the nurse were required to comply with professional, ethical, and other relevant principles.

Maintaining professional boundaries was an integral part of the provision of health services, she noted in the decision.

"I consider the nurse contravened professional boundaries and ethical standards by initiating contact with the young man outside of a professional setting, and sending messages of a personal nature."

The inherent power imbalance existing between healthcare consumers and their providers continued after the end of the professional relationship, because of the nurse's knowledge of the young man's personal circumstances and mental health, Caldwell said.

"Trust is fundamental to the relationship in ensuring the consumer is assured the provider is acting in the consumer's best interests.

"It is critical that relationships between health professionals and their clients stay within the professional realm, to avoid any exploitation or abuse of power."

It was recommended the nurse undertake further training on identifying and maintaining professional boundaries.

Caldwell also suggested the Nursing Council of New Zealand consider the fitness of the nurse to practice and whether any competency or conduct reviews were required.

She further proposed the mental health service undertake an audit of the nurse's caseload to ensure there were no other cases of professional boundaries being crossed, and provide appropriate support if necessary to any affected patients.

The nurse was also referred to the Director of Proceedings to consider any further action against the provider involving the Health Practitioners Disciplinary Tribunal, the Human Rights Review Tribunal or informal resolution by way of agreement.

"The potential harm to a vulnerable young person by behaviour initiated by the nurse was significant, and there is public interest in ensuring that such a risk is minimised."

- Leighton Keith, Open Justice