The disclosure is made in a new report painting a bleak picture of child mental health, which has prompted children’s services to call on the government to make the issue its "top priority".
Research shows that there were 2,334 pupils requiring additional support for learning because of a mental health problem in 2015 – more than double the 1,086 recorded in 2011.
The report reveals that pupils with mental health issues who need additional support are almost 10 times more likely to be excluded than pupils with no special needs.
They are also more than twice as likely to be excluded as additional support needs (ASN) pupils overall.
The attainment and school attendance of these pupils are also worse than for other ASN pupils.
The problem continues beyond school: a "significantly greater" proportion of school-leavers with mental health problems are unemployed but not looking for work or training.
The alarming statistics appear in an annual government progress report on additional support for learning legislation, which this year focuses on mental health in schools. At their most severe, mental health problems – for example, severe anxiety – can "significantly interfere with cognitive, emotional and social abilities", the report says.
Euan Duncan, president of the Scottish Secondary Teachers’ Association, said: "Rising mental health issues amongst youngsters are a serious concern, and local authorities need to consider carefully whether support in this area is as good as it could be."
This is an edited version of an article in the 1 April edition of TESS. Subscribers can view the full article here. This week's TESS magazine is available at all good newsagents. To download the digital edition, Android users can click here and iOS users can click here