Children and young people have waited up to 666 days to access mental health services after being referred for treatment, according to new figures.

The statistics acquired by the Scottish Liberal Democrats show the longest wait for children who started treatment in 2016-17 was 666 days in Lothian, 623 days in Highland and 385 days in Grampian.

For those currently waiting to start treatment, the longest wait was 611 days in Fife and 448 days in Ayrshire and Arran.

Party leader Willie Rennie said the figures, obtained through freedom of information legislation, were "appalling".

He said: "Waiting more than 600 days for help must feel like a lifetime. SNP ministers should hang their heads in shame.

"These new statistics show why SNP Government was so wrong to reject the opportunity to invest to transform mental health services in its budget.

"It shows the damage caused by its letting the mental health strategy expire for 15 months. Its replacement has finally been published but charities and pressure groups have rightly declared it lacks ambition, detail and investment.

"For years, the First Minister has told me time after time of her commitment to mental health but there is very little evidence of improvement. The urgency and the scale of the investment that we need to see is simply not there."

Mr Rennie said his party would end the "underfunding" of mental health, set up new units for children and ensure more mental health professionals were available at more locations.

In response, a Scottish Government spokesman said the most recent official statistics showed the number of children and young people seen by mental health services within the target time had increased for the second quarter in a row.

He said: "Our recently published Mental Health Strategy contains a range of actions that focus on prevention and early intervention to meet the mental health needs of children and young people, to help prevent the development of mental health problems, and to step in promptly where they develop.

"We've set out 40 initial actions to better join up our services, to refocus them and to deliver them when they are needed. Over the next five years we will increase the mental health workforce by 800 in key settings like GP surgeries, A&E, prisons, and police custody suites, with funding increasing to £35 million to support this training and recruitment.

"We will also soon commission reviews into school counselling and rejected child and adolescent mental health service referrals, as a foundation for making further