The number of admissions of young people with mental health problems to non-specialist wards has increased.

A report from the Mental Welfare Commission revealed there were 207 admissions of under-18s to non-specialist units such as adult psychiatric and paediatric wards in 2014/15, an increase from 202 the previous year and up 39% since 2008/09.

The majority of the 175 young people involved were aged 16 or 17 but their number also included a nine-year-old boy and a 10-year-old girl.

The commission said that in many cases a non-specialist ward may be the best option for short stays in a location close to the family home, but questioned whether all such admissions were made through a positive choice.

It also raised concerns about the "very variable" level of support available to under-18s in non-specialist wards.

The report highlights that in some complex cases, plans were being made to transfer young people to specialist units in England "because there were no suitable beds available in Scotland".

The Scottish Government has announced a £100 million fund to improve mental health services, particularly those for children and adolescents.

Mental Welfare Commission chief executive Colin McKay said: "The concern is that a vulnerable young person can be on a ward that is not appropriate to their situation and have little or no specialist care.

"We welcome the additional funding announced by the Scottish Government for young people with mental ill health.

"Money on its own will not solve the problem - the government and local boards need to look hard at what is causing young people to be placed in non-specialist services, and whether particular groups are not receiving the support they need."

A spokesman for the Scottish Children's Services Coalition said: "While we welcome the increased investment the Scottish Government is putting into child and adolescent mental health services (CAMHS), these figures out today are deeply disturbing and highlight the need for greater impatient provision.

"Our concern is that these young people may not be getting the age-appropriate support and care that they require, and the Scottish Government must look to ensure that NHS health boards are providing the support these vulnerable young people so desperately need."

Mental health minister Jamie Hepburn said demand for specialist services had increased through better diagnosis and more people being prepared to come forward.

He said: "The number of children and young people seen by specialist CAMHS has increased from around 1,000 in June 2014 to over 1,500 in June 2015, which may also have resulted in increased demand for access to inpatient beds.

"Since 2009, we have increased the child and adolescent mental health services workforce by 28.4% and the number of specialist adolescent inpatient beds has increased from 42 to 48 beds.

"The £100 million fund we announced earlier this year will be key when it comes to making the further improvements we need.

"Through this substantial fund, we will be able to extend capacity, improve access to services and promote innovation and new ways of treating people."