Research conducted for the Royal Commission on Criminal Justice found that 7% of all suspects detained by the police suffer from mental disorder. One of the Commission's recommendations was that the use of appropriate adults should be investigated further.

Individuals with mental health problems or learning disabilities may be especially vulnerable to the distress and pressures caused by the experience of arrest and police detention. Under the Police and Criminal Evidence Act 1984, and the associated Codes of Practice, mentally vulnerable suspects are entitled to special protection, in addition to the rights of any arrested person. This protection includes the attendance of an "Appropriate Adult" who could be a relative, friend, guardian, mental health professional or responsible adult who must be independent of the police.

·        The Royal Commission on Criminal Justice (1993) Research Study no: 12 Gudjonsson G et al. Persons at Risk During Interviews in Police Custody: The Identification of Vulnerabilities. London. HMSO.

·        An extreme example of what can go wrong is that of Anthony Everett who because of his mental health problem, confessed to 391 burglaries and thefts during interview by the Essex police. He was charged and went to prison, only then was it realised that he could not be guilty for many of the offences as he had actually been in prison when most of them had been committed.

·        There have been other cases where people who could have been classified as vulnerable have services of an appropriate adult and this has instigated research into this field.