It’s a sad fact, but even in the supposedly enlightened 21st century, mental health issues are still something of a prickly subject, despite numerous attempts to bring them out into the open.

This film is one of several programmes showing in the Headroom season, a two-year mental health and wellbeing project.

It aims to raise awareness of the importance of good mental health and de-stigmatise the problems surrounding the mental illness issues which face up to one in four of the population, including anxiety, stress, depression and nervous breakdown.

This documentary, presented by the former Tory MP, tells the story of Gary, a young boy Michael Portillo went to school with almost 40 years ago.

A gifted student and musician, Gary was cherished by his family, who were at a loss to explain why, just before his 16th birthday, he committed suicide, leaving a note to his parents in which he asked them “Please, don’t be sad.”

Here, Gary’s parents Jeanette and Ronnie, and his younger brother Andy, tell Portillo why they simply cannot fulfil that request.

Ronnie says: “The terrible grief you feel immediately stays with you for the rest of your life. It was 40 years ago, and I’m 80 now and it’s still exactly the same feeling.”

It’s fair to say this is an inherently sad film, but in a beautiful and hugely poignant moment, Gary’s music, composed before his death and only rediscovered during the making of this programme, is played for the first time by his brother.

There’s no doubt this was a difficult and emotional film to make, but Portillo’s reasons for taking part are simple. He says: “This film is an accolade to a very gifted friend who chose, almost 40 years ago, to give up on life. It is also a tribute to the courage of his parents who have suffered agony every day since.”

Anyone keen to know more about mental health issues and the Headroom season itself can log onto the website, www.bbc.co.uk/headroom.

Executive producer Nina Bell says: “The aim is to actively encourage people to assess their mental wellbeing and take simple, practical steps to manage or improve it.

”And they can do this in many ways - online at the Headroom site, by taking part in a Headroom event or engaging with a variety of programming across the BBC’s networks.”

She adds: “It’s about giving people the tools to deal with the everyday stresses and strains of life as well as providing a safe place to start finding answers to more complex problems.”

Among the many resources available to those who log on to the site is Ruby’s Room, run by actress-turned-trained psychotherapist Ruby Wax.

Visitors will have the chance to see her weekly webcast in which she will invite viewers to email their problems, experiences or views on a particular mental health issue, and each week she will explore a different topic suggested in her inbox.

Ruby says: “People can’t see it, so they don’t know how to help and you can’t wish it away.”