Depression self-portrait
Prime Minister David Cameron has been asked to provide more support for teenagers with mental health problems, such as depressionLloyd Morgan/Flickr

A grieving father who lost his son to depression is urging Prime Minister David Cameron to incorporate a rethink of child mental health services in the Conservatives election manifesto.

Edward, Steve Mallen's 18-year-old son, died last month after he was hit by a train.

The Cambridge teenager rapidly declined into deep depression after Christmas 2014. Mallen has written to the prime minister and is advocating for the government to put mental health on an even keel with physical health.

Mallen has written to the Cameron, advocating for the government to put mental health to be given the same importance as physical health.

In his emotional note, Mallen outlined his deep despair: "I would tear open the sky to bring my son back. He fell straight through the cracks of a broken and totally adequate care system. This must never happen again."

Mallen has given his support to Time To Mind, a campaign by The Times to improve child mental health services.

Since 2010, NHS spending on children's mental health services had dropped by more than 6% in real terms – which is equates to nearly £50m ($73.7m).

According to UK charity YoungMinds, nearly 80,000 children and young people suffer from severe depression.

The Liberal Democrats pledged to commit extra funding for mental health services in next week's budget.

"A mental health package will be announced in the budget and there will be a children's component. Nick [Clegg] has made mental health a huge thing for our party – it's going to be one of the five key pledges on our manifesto," chief secretary to the Treasury, Danny Alexander told The Guardian.

The £8.5m ($12.5m) package will double financial support for British veterans and fund intervention programmes to combat the development of serious mental health conditions from an early age.

The commitment was announced days after charity Combat Stress revealed that the number of British veterans of the Afghanistan war receiving treatment for post-traumatic stress disorder has risen from 102 in 2010 to 945 in 2015.

The Samaritans provides a free support service for those who need to talk to someone. It can be contacted through its website or on 08457 90 90 90, 24 hours a day, 365 days a year. Call charges apply. Depression Alliance also provides advice and support for people affected by depression.