Treatability test
From 3/11/08 when the relevant provisions of the MHA 2007 come into force, this test no longer applies: see Appropriate treatment test replaces treatability test and applies to all patients under long-term detention.
The leading case on the test is Reid v Secretary of State for Scotland [1998] UKHL 43.
The test only applied to psychopathic disorder (and, less contentiously, to mental impairment) and stated that treatment must be "likely to alleviate or prevent a deterioration of his condition".