It would be impossible to have all medications for mental health problems prescribed by a specialist, a senior doctor has said.

John Mitchell, a senior medical adviser to the Scottish Government, said GPs should not currently prescribe antidepressants to children as this should be done by a specialist mental health service.

But he said extending this advice to cover all medications for mental health would “not be possible”.

The doctor was speaking to Holyrood’s Public Petitions Committee, which is taking evidence on a petition started by a mother whose 16-year-old daughter fatally overdosed.

Annette McKenzie previously told the committee her daughter Britney, who had informed her doctor she suffered from depression and anxiety and was having suicidal impulses, was prescribed a month’s supply of a betablocker in June 2016.

Sixteen days later, the teenager took a fatal overdose.

Ms McKenzie, from Glasgow, did not know her daughter had been given the medication and she wants the law changed so under-18s cannot be prescribed drugs to treat mental health issues without parental consent.

Mr Mitchell said he would not expect a GP to prescribe antidepressants for a child as it contravenes NHS guidelines, but he said in this case the medicine was not an antidepressant and its primary purpose was not to treat anxiety.

For children being prescribed antidepressants, the initial prescription would be expected to come from specialist mental health services.

Committee convener Johann Lamont asked if initial prescribing from a specialist should apply to other medicines being given to address mental health problems, such as medication for anxiety which is not an antidepressant.

Mr Mitchell said: “We have to allow clinical judgment. We have to allow fundamental clinical decisions to be made.

“There are a wide range of different medical treatments used, some of those are reserved for specialists and some of those aren’t, and it’s fundamentally up to the clinician who is assessing the situation and then initiating prescribing, if that is of medicine.

“To say that all prescribing of everything under any circumstances for mental health problems should only be done by specialists, I think would be not possible, because I don’t think that’s possible in physical health.

“We also have to remember that prescribing is not necessarily done by doctors.

“It has to be proportionate. I think we have to accept GPs may chose, for example, with somebody who is saying I’m anxious and the problem I have is that my heart is beating so fast that is troubling me, to think about using a medicine that would maintain their heartbeat at a regular level rather than going to antidepressants or a sedative medicine.

“To bring in limits to the ability to prescribe the broadest range of medicines for clinicians, I think, would be impossible.”