A teenager with long-term mental health problems has been prosecuted twice in the last nine months after threatening suicide near busy roads.

The 19-year-old woman was pulled to safety from a road by Greater Manchester police officers last Sunday, while still serving a community order for her previous offences.

She was convicted of two counts of assault by beating and ordered to pay £100 in compensation at Manchester magistrates court on Tuesday, after scratching two officers who detained her.

She was also convicted of criminal damage after writing her name in blood on the wall of her police cell while being held in custody.

District Judge John Timperley told the woman to “get help for your mental health difficulties rather than wasting the time of people needed to provide a service to the public”.

Last year, the college student was prosecuted for causing a public nuisance after threatening to kill herself near a motorway.

Police said her actions had caused delays to thousands of motorists and cost hundreds of pounds in police resources.

The Labour MP Barbara Keeley, the shadow cabinet member for mental health, told the Manchester Evening News she found the case “deeply worrying”.

She said: “This young woman, experiencing a mental health crisis, should have been taken to hospital not held in a police cell. When the police intervene to support someone in a mental health crisis their role should be to provide support, not to criminalise their actions.”

The woman, who has a history of mental health problems and has been diagnosed with an emotionally unstable personality disorder, said authorities “just don’t get it”.

“Every time I go to A&E, they don’t know what to do with me,” she told the MEN. “People with personality disorders ... they don’t know what to do with it.”

Greater Manchester police declined to comment on the specific case, but said it worked in conjunction with the NHS, Greater Manchester’s mental health team and probation services when mental health was a factor in criminal proceedings.

A spokesperson said: “Our officers are often the first responders to people suffering a mental health crisis, which can be extremely challenging but our main priority is always the welfare of the individual and members of the public.”

Greater Manchester’s Mental Health NHS Foundation Trust said that “enduring complex mental health needs” did not exclude individuals from having to comply with the law.

• The headline and text of this article was amended on 17 January 2020 because an earlier version incorrectly said that the teenager was prosecuted three times. She was prosecuted on two occasions.

In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org.