But after Mr Russell's death it emerged he had disclosed his troubled thoughts to other young people on his Facebook page, in text messages and possibly emails.
Mrs Russell suggested there needed to be more counsellors at schools and more education about where parents and young people could go for help.
Dr Bain said: "It's clear Mrs Russell you did absolutely everything you could to help your son and it begs the question what more could have been done to assist him."
It appeared confidentiality concerns by others had become a barrier to this type of information being disclosed to family members and possibly delaying help to those who need it, he said.
Mr Milne's death in July 2011 catapulted his family into a tumult of grief and a frustrating search for answers.
His parents Colin and Marianne Milne, who were at the inquest along with Mr Milne's partner, urged Dr Bain to look into why their loved one had fallen between the cracks.
The family lodged a formal complaint with the Health and Disability Commissioner regarding what they believed was a lack of urgency received in the lead-up to his death.
Health and Disability Commissioner Anthony Hill, who investigated the complaint, concluded the tragic outcome could not have been foreseen by health providers and decided to take no further action.
Mr Milne's partner reiterated her concern about the lack of supervision over Mr Milne's case particularly in light of his medical history and a medication change.
Funeral celebrant Martin Elliott, who presided over Mr Milne's funeral, told Dr Bain that in his view there was clear evidence of a "failure in the system", and the lack of the robustness, particularly the need to consult better with family members, needed urgent investigation.
Dr Bain told both families he would be attending a suicide-prevention conference in Rotorua on Friday which would also involve experts from overseas.
Dr Bain adjourned the inquest hearings and reserved his findings.
But he said the focus of his findings when they were released clearly must encapsulate some beneficial recommendations to tackle "alarming" statistics which were twice this country's accident rate.
Helplines
Lifeline 0800 543 354
Youthline 0800 376 633
Kidsline 0800 543 754 (weekdays 4-6pm)
What's Up 0800 942 8787 (noon to midnight 7 days, for young people aged 5 to 18)
Depression Helpline 0800 111 757
Samaritans 0800 826 666 (lower North Island and Upper South Island) provides confidential, non-judgmental emotional support through their telephone helpline 24 hours a day, 7 days a week, to people in distress.
Healthline 0800 611 116
Source: Ministry of Health