Data shows NHS Forth Valley has missed a key waiting time target for child mental health support.
Young people have been waiting a total of nearly 400,000 additional days for support since April 2019.
The target is for children to be seen within 18 weeks.
The Scottish Lib Dems have called for more investment in child mental health services.
An NHS Forth Valley spokesperson said:
"Significant changes have been made over the last six months to help increase capacity and reduce waiting times for children and young people who require specialist mental health support.
As a result, recent figures show that our performance against the 18-week referral to treatment (RTT) target has improved by 100% and rates of non-attendance have also more than halved in the same period. There are currently only two patients waiting over 18 weeks to be assessed and very long waits have been eliminated.
Following a successful pilot project, children and young people can now access support from specially trained Primary Care Mental Health Workers in local GP Practices across Forth Valley. We are also working alongside council partners to increase access to a range of new services which aim make it quicker and easier for children and young people to access mental health support in the community at an early stage."