There is no consistent pattern of services in England for people with
a learning disability who offend or have severe anti-social behaviours
('mental impairment'). In one English health region, the mental impai
rment service comprises two residential units on hospital sites. The f
irst of these (Unit A) operates as a medium-secure unit, assessing and
treating patients referred by the courts. The second (Unit B) has a l
ower level of security, and provides long-term treatment for people wi
th a mental impairment domiciled in its hospital's catchment area. Alm
ost all the patients in the two units had mild learning disabilities,
and substantial minorities had psychiatric and/or neurological disorde
rs. A higher proportion of patients at the unit with the lowest level
of security had psychiatric disorders and disturbed behaviour. This an
omaly results from the lack of local mental impairment services throug
hout the region, which makes it difficult to discharge patients from U
nit A. It is recommended that priority be given to the development of
local mental impairment services rather then new medium-secure assessm
ent units.