Kevin
Most of what you want is not directly in the public domain, try a an internet search for "dwp support for vulnerable claimants", this should bring up some relevant content, in particular a RightsNet article the appears to cover PIP telephone communications.
The PIP Assessment guide (in the Members Only area) has a number of references to suicide risk.
You can also make Freedom of Information requests to both the DWP and ATOS.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
