Researchers have discovered a new enzyme, known as BACE2 destroys beta-amyloid, a toxic protein fragment that affects the brains of patients who have the disease.

People who are affected by physical harassment, including sexual, are at higher risk of developing mental health problems. Researchers claim that most mental health problems are unrecognised because of lack of services to support their needs.

Researchers from the Cardiff University have found that people who have faced physical or even sexual harassment can develop mental health problems. They claim that their mental problems are usually more serious and longer lasting than their physical injuries.

"Having treated people injured by violence for many years, I'm convinced that the mental health problems that are inflicted are often more serious and longer-lasting than their physical injuries," said Professor Jonathan Shepherd, Professor of Oral and Maxillofacial Surgery at Cardiff University, in a statement.

More than 300,000 victims of violence are treated in emergency departments in England and Wales each year. Among them, nearly 40 percent have mental health problems. Even though mental health problems after physical harassment are common among victims, they are often neglected.

To address the mental health problems of victims, researchers have come up with new guidelines that could help doctors and health departments to recognise victims facing mental health issues.

"We hope this guidance will help make sure that people who are victims of violence get the help they need," said Shepherd.

The new guidelines include a new stepped care pathway to show how emergency departments, GPs and the criminal justice system can work better together to identify those people who show signs of mental ill health and provide them with information about relevant support services.

The guidelines recommend that health professionals who treat victims should first look for any mental health problem. Once the patient's problems are recognised, health professionals should provide additional care and support to the victims and see to it that their problems are solved.

"Our trained volunteers have been helping victims deal with the emotional and psychological effects of all kinds of crime for nearly 40 years. We are therefore keenly aware of the psychological impact that being a victim of violent crime can have," said Javed Khan, Chief Executive of Victim Support, in a statement.

He said Victim Support had systems to identify and refer victims to mental health services, where it was needed.

Khan called for greater collaboration between all agencies and individuals involved to ensure that more victims with trauma-related and mental health conditions were identified and appropriately referred.

"We look forward to working with the Royal College of Psychiatrists and other parties to ensure more victims get the help they need," he said.