Self-harming figures for West Sussex have been higher than the national average for the past five years.
Women aged 15-29 are the most likely to be hospitalised.
The figures were discussed at a meeting of West Sussex County Council’s health and adult social care scrutiny committee last week.
Members said early intervention was ‘crucial’ for youngsters with mental health problems.
Chairman Cllr Bryan Turner said: “We all know and accept that mental health issues do surface when people are young and if they’re not tackled early they stay there for quite a long time.
“So early invention is crucial and work in schools is absolutely crucial.”
Self-harm is not isolated to people who deliberately physically hurt themselves. It includes putting themselves in dangerous situations and self-neglect.
A report from Rachel Jevons, the county’s public health lead for mental health, said that between 2013 and 2018 there were 9,254 emergency hospital admissions for self-harming in West Sussex, with the highest rate in Worthing.
In 2018/19 alone, there were 1,845 emergency admissions county wide, up from 1,743 the year before.
Ms Jevons’ report said rates of self-harm in Adur, Arun and Worthing had been higher then the national average since 2010/11.
Cllr Amanda Jupp, cabinet member for adults and health, shared a ‘sobering statistic’, telling members that an audit carried out in 2017 showed ‘one-third of all those who died through suicide had a history of self-harm’.
Another extremely worrying fact came from Danielle Wilkinson, the council’s schools and colleges programme manager for self-harm.
Ms Wilkinson said there was a ‘significant level of self-harm activity in schools’ from primary school up, with the need for more training in how to spot the warning signs.
The prevalence of ‘toxic’ videos online encouraging children to self-harm was of huge concern.
Cllr Turner asked why such material was not removed, adding: “I don’t understand why there’s a reluctance in these companies to actually do that.”
It was suggested that social media could be used to engage with young people, to support them and to help them.
Cllr Turner said: “If social media is the enemy here, it’s also part of the answer as well.”
Report by Karen Dunn, local democracy reporter