The number of antidepressants prescribed to children in England, Scotland and Northern Ireland has risen over the past three years, figures obtained by BBC's File on 4 reveal.

In England, there was a 15% rise. Scotland saw a 10% increase. And in Northern Ireland the number rose by 6%.

In total, there were 950,000 prescriptions issued between April 2015 and March 2018.

Experts have linked the rise to waits for specialist mental health services.

Antidepressants should prescribed to children only under close supervision.

NHS England, NHS Scotland and the Health and Social Care Board in Northern Ireland all say they are committed to improving child mental health services.

NHS Wales was unable to provide prescription figures because it does not hold the data requested.

The figures were obtained by Freedom of Information requests and relate to a group of powerful antidepressants known as selective serotonin reuptake inhibitors (SSRIs).

The total number of prescriptions rose from 290,393 in 2015-16 to 330,616 in 2017-18.

The steepest increase was seen in the youngest patients, those aged 12 and under, where the number of prescriptions rose on average by 24%, from 14,500 to almost 18,000.

Dr Bernadka Dubicka, who chairs the child and adolescent faculty at the Royal College of Psychiatrists, said: "Currently only one in four children and young people are treated for their mental health problems.

"The fact that prescriptions for antidepressants are rising could reflect a slow but steady move towards treating everyone who is unwell.

"But the importance of giving children access to psychological therapies cannot be overstated.

"What we don't know from today's data is why these antidepressants are being prescribed, and how.

"It is vital that they are being used judiciously, monitored carefully, and the risks and benefits of taking them are assessed in each individual case."

The mental health charity Young Minds says waiting times for specialist child and adolescent mental health services (Camhs) have been increasing too, making it difficult for families to get support.

Marc Bush, chief policy advisor at Young Minds, said: "The government recently suggested that the average waiting time for general access to Camhs is around 12 weeks, which is a long time to be in distress.

"And that is why front-line professionals are turning to prescription pads, because they're thinking, 'I'm seeing someone in front of me in crisis with a level of distress I don't want to leave them with - how do I offer them some kind of alleviation from that?'"

In rare cases, antidepressants can trigger thoughts of suicide and self-harm in children.

And the National Institute for Health and Care Excellence (NICE) has clear guidelines:

Prescriptions should be written by a child psychiatrist within Camhs, not GPs

Antidepressants should be offered only concurrently with psychological therapies

The patient must be monitored to check for adverse reactions

However, File on 4 has heard concerns these guidelines are not always followed.