What do you do if, aged 12, you find yourself feeling hopeless and terrified of the world around you? To whom do you turn? Melvyn Bragg has revealed that his struggle with depression began at this age. "I had clinical depression but I didn't know who to talk to," he said. "I don't think anybody who hasn't been through depression knows what it's like to be frightened out of your mind every day from the moment you wake up to the moment you go to sleep."

A child with such feelings is clearly in need of urgent assistance from adults, but for many, all these years after Bragg first struggled, help is still not forthcoming. Those who work with children know this, and have been calling urgently for an overhaul of mental health services. The charity Kids Company has launched a campaign called "See the child. Change the system", supported by some of Britain's leading children's authors – they are shocked that one in seven councils in England have been deemed by Ofsted to be failing vulnerable children. The mental health charity Young Minds is also campaigning, following a freedom of information request that revealed sweeping freezes and cuts to mental health service budgets for children and teenagers.

Voices are rising, but whether politicians will listen is another matter. Kids Company founder, Camila Batmanghelidjh, has said vulnerable children are "relegated to the bottom of the political pile", and social workers describe being unable to provide adequate support due to cuts. Childline stated that reports in self-harm in 2013 had risen by 41% from 2012, while reports of suicidal thoughts increased by 33%.

Media outlets are quick to blame social media for the deterioration in children's mental health – an easy, convenient scapegoat. There has been a number of widely reported suicides of shockingly young children who had been bullied online, leading to rampant speculation. But whatever the perceived causes, we know that to leave a vulnerable child unassisted can lead to the very worst of outcomes. If the child survives their formative years without proper support, they can be left to struggle with mental health problems throughout adulthood.

Given the dearth of services, children and families come up with other coping mechanisms. Recently, while having a clear-out, I came across a small yellow box within which were five worry dolls. Originating in Guatemala, worry dolls are vessels for a child's anxiety – the child talks to them, tells them their fears, then places them under their pillow. It struck me that I had spent my childhood surrounding myself with talismans in an effort to combat the fact I was scared and anxious all the time. There were dream catchers to stop the nightmares, comfort blankets cuddled way past the acceptable age, a gift of worry beads (there was a lot of worry) in an attempt to get me to stop picking at my skin compulsively until it bled.

Twelve was the worst year. My parents split up, I was being viciously bullied, and it was becoming clear that my brother, then six, was so severely disabled he would never lead a normal life. My mum tried several times to get me counselling, and although our family was known to social services the waiting list was endless. I'm probably still on it.

I resorted to books, angry music and writing terrible poetry; Melvyn Bragg buried himself in schoolwork. Others use drugs or alcohol. None of these is sufficient. In hindsight, I realise I talked more to those worry dolls than I ever did to an adult, and that is what it all boils down to. The country's adults are failing children – children far worse off than I ever was – and unless we do something now, we will continue to let them down.