National Mental Health Commission chief executive Christine Morgan has labelled it a world-first plan to protect the mental wellbeing of children under 12.

"We've got plenty of youth mental health strategies, plenty of mental health strategies for adults. We've never had one for children before," she told reporters in Canberra on Tuesday.

The strategy uses previously announced funding including for subsidised psychology sessions for family members and carers, 15 mental health clinics specifically for under-12s and boosting children's helpline funding.

It aims to equip parents to spot the signs of mental distress so they can get their children help before things escalate.

For example, a sore tummy might be a sign of anxiety.

"Don't wait for a sign of illness - look for when your child appears to be struggling a bit," Ms Morgan said.

"Do listen to your instincts, because if you notice something is slightly different in your child, then probably there is.

"How are they enjoying their daily activities, are they enjoying the daily activities, are they a bit anxious about going to school, are they making excuses for not going to school, are they moody, are they engaging with their friends?"

Half of all adult mental health conditions emerge before the age of 14 but young children frequently don't receive professional help.

Ms Morgan hopes letting children know it's OK to feel like they're not coping, and making sure they can get help, can prevent more serious or chronic illness.

Health Minister Greg Hunt said prolonged COVID-19 lockdowns had produced immense mental strain.

"What is absolutely important is there's hope. There's hope for individuals and there's hope for parents and the community as a whole," he said.

Lifeline 13 11 14

Kids Helpline 1800 55 1800 (for people aged 5 to 25)

Australian Associated Press