Smith, who specialises in depression and anxiety, has just released her fifth book, called Knowing. It offers mental-health coping mechanisms for youth. She believed it could be a powerful preventative tool in the battle against teen suicide.
Anxiety is a survival mechanism that gets switched on to deal with threats, Smith said. It would be a typical and useful response when confronted with a tiger in the wild. But in the contemporary world it's being switched on for the wrong reasons.
The psychologist believed youth lacked resilience to deal with problems which was a result of a rapidly changing world and growing up in privilege.
"Young people will become anxious if they're not part of the A team, not wearing the right label or their hair isn't cut and coloured in the right way. These clearly are not life-threatening situations.
"The system is being constantly switched on to false meaningless perceived threats."
The cause of anxiety is a cluster of things, Smith said. It could involve genetics, environment, nurture, family, media exposure, bullying or the result of a physiological conditions.
But one element that could be the reason for an increase in the disorder is the rapid changes people in first world countries face and a lack of resilience. Smith believed entitled children who were being overindulged by their parents lacked problem-solving skills.
"Anxiety is on the rise because too many of young people are not resilient. Too many don't know how to adapt.
"If you've never had to solve a problem how are you going to solve one?"
The Auckland psychologist is perhaps most well known for creating her alter ego Doctor Know in 2015 and answering questions from young people on a blog. She now has 5000 regular followers from around the globe.
After an interview with the US edition of The Guardian last year Smith's blog had 11,000 questions in one hour.
"It was an avalanche of young people looking for help. Doctor Know had tapped into the main vein of unmet need in youth mental health services globally."
The questions inspired her to write the book Knowing.