The Department for Education's mental health advisor, Natasha Devon, said kids need support from bullying, rather than being prescribed medication.
"If a child is being bullied and they have symptoms of depression because they are being bullied, what they need is for the bullying to stop," Devon said at the Headmasters' and Headmistresses' Conference.
"They need to feel safe again. They don't necessarily need anti-depressants or therapy."
Devon said mental health problems among school children are "much worse" than people think.
"It's my belief that many of these struggles could be avoided if we get our approach right," she added.
'If we don't, we're giving with one hand and taking away with the other. And we run the risk of medicalising childhood."
Devon also discussed the amount of pressure children are facing at school, saying education has become "fiercely competitive".
"You cannot apply an adult amount of pressure to a child brain and expect them to cope," she said.
"Being a young person today is harder than it has ever been."
Nick Harrop, campaigns manager at YoungMinds, supporting young people's mental health and wellbeing, said anti-depressants for children should never be the only course of action.
"GPs all too often prescribe antidepressants to young people because they don’t know what else to do," he told The Huffington Post UK.
"Child and adolescent mental health services are a postcode lottery, with unacceptably long waiting times in many areas, and with a high threshold for treatment because services are overwhelmed.
"We believe that anti-depressants can have a place in treating some mental health conditions, but they should never be the only course of action.
"It’s also really important that children and parents have comprehensive information about the effects that anti-depressants can have.
"Children and parents need to be able to make informed decisions about whether medication is the right approach."
In March 2016, it was revealed the number of children in the UK prescribed anti-depressants increased by more than 50% from 2005 to 2012.
The World Health Organisation (WHO) revealed the findings and stated that the increase in the use of these drugs to treat young people was "a concern".
Over those seven years there was a 54% increase in the number of young people prescribed anti-depressants in the UK.
Dr Helen Webberley, GP for www.oxfordonlinepharmacy.co.uk, said parents must seek medical advice before making any decisions to take their children off a course of antidepressants.
"If a parent is worried about the medication that has been prescribed for their child, the recommendation is to continue taking the medication but to discuss their concerns with their GP or specialist as soon as possible," she previously told HuffPost UK.
For more information on mental health medication for children, visit HeadMeds.org.uk - a website powered by YoungMinds.