R (MacDonald) v MHRT North West Region  EWHC Admin 716
Pre-Reid challenge to non-discharge of untreatable psychopath.
A change made by the Mental Health Act 2007 is related to this case. See Appropriate treatment test replaces treatability test and applies to all patients under long-term detention 3/11/08
Possible Bailii link (not there when last checked, but it might have appeared since 0700 this morning!)