This year's theme is "young people and mental health in a changing world".
Local churches have already flagged up World Mental Health Day on Sunday.
"A healthy mind is every bit as important as a healthy body, but the stigma associated with mental health issues is often a huge factor is preventing those struggling, from seeking the right kind of help and support".
Heather says, "Approximately one-half of chronic mental illness begins by the age of 14".
And this week sports organisations and youth groups will also spend some time with each of their teams or groups before or after training or meeting to discuss mental health. All 10 of the young people who used the decision aid were offered personalized lists of potential sources of help and said that they would follow its advice and would recommend it to other self-harming teenagers.
Many people in society are affected by mental illness.
At least 177 countries were featured in a report from WHO earlier this year which charted the progressive implementation of its 2013 global action plan on mental health.
One in five adults experiences mental illness in any given year, and 17% of high school students report seriously considering suicide.
"I had CBT while on Strictly because I had stage fright and it was the first time I thought about mental health and the fact that you can change the way you think and make yourself more comfortable by talking to someone". "The challenges are to help people understand that it is an illness and there are medicines and treatment available".
And we need that true parity between physical and mental health, not just in our health systems but elsewhere as well - in our classrooms, our workplaces, in our communities too.
Present estimates show people with mental illnesses account for almost 6.5% of India's population and is projected to increase to 20% by2020.
"Mental health is the foundation of human capability that makes each life worthwhile and meaningful".
And in this landmark agreement we see more than 50 countries have supported the declaration to achieve equity for mental health in the 21st Century. The answer to increasing well being and mental health will come not only from policy change in the house of commons, not only in the curriculum at school or college, but in the way we all relate to each other, the way we interact and support each other.
This week they have been focusing and working on the Public Health Agency's Take 5 campaign - its message is "Give, Be Active, Connect, Keep Learning and Take Notice".