There is a “desperate” need for more staff, the Royal College of Psychiatrists in Scotland has said.
New figures from Public Health Scotland show 70 per cent of children and young people were seen within 18 weeks from September to December last year.
This is a drop from 79 per cent in the previous quarter, and from 73 per cent in the same period the year before. The Scottish Government target is 90 per cent.
Dr Helen Smith, chair of the CAMHS Faculty at RCPsych in Scotland, said: “With waiting times on the rise again, the Scottish Government really need to be stepping up a gear when it comes to the mental health of our children and young people.
“CAMHS desperately need more staff to be able to deliver specialist care and there also needs to be much greater co-ordination between services to ensure every young person gets the right support they need at the right time.
"Early intervention is necessary to prevent a generation of young people suffering with mental health difficulties."
It comes as waiting times performance at accident-and-emergency (A&E) departments reached their fifth-worst on record.
Some 71 per cent of patients were admitted, transferred or discharged within four hours in the week to March 6, against a target of 95 per cent.
Scottish Conservative shadow health secretary Dr Sandesh Gulhane warned lives would be “needlessly lost” because of the delays.
Labour health spokesperson Jackie Baillie urged the Government not to let the “A&E crisis” become normal.
“Week after week, the chaos in our emergency services has been putting lives on the line – but the SNP are posted missing,” she said.
Scottish Liberal Democrat leader Alex Cole-Hamilton added that “the fact that this crisis has carried on for so many months is shocking”.
Mental health minister Kevin Stewart said a “record number of children and young people” had started receiving CAMHS treatment in the last three months 2021, adding that the government is committed to meeting the 90 per cent standard.
Some £4.25 million has been invested this year to help health boards tackle CAMHS backlogs, he said.