Tier 4
These are essential tertiary level services for children and young people with the most serious problems, such as day units, highly specialised outpatient teams and in-patient units. These can include secure forensic adolescent units, eating disorders units, specialist neuro-psychiatric teams, and other specialist teams (for children who have been sexually abused, for example), usually serving more than one district or region.
Practitioners working in CAMHS will be employed by a range of agencies. Many (but not all) of those working at Tier 1, for example, will be employed directly by the PCT or the local authority.
CAMHS specialists working at Tier 2 are less likely to be working for the PCT (although some of them might be), and more likely to be working for another NHS trust (or the local authorities in the case of educational psychologists).
Most practitioners working in the more specialised services at Tiers 3 and 4 will usually be working for other types of NHS trust (such as mental health trusts, acute trusts or care trusts, for example).
From what I can tell it's a classification system of different psychiatric services. Here's the link I got the information from
http://www.everychildmatters.gov.uk/health/camhs/
Hope it helps Kel.
