here are a couple of articles
https://www.psychologytoday.com/blo...errorists-actually-terrorists-or-mentally-ill
http://www.medscape.com/viewarticle/855849
For academic papers there is an overview of the literature here:
for example:
https://www.surrey.ac.uk/politics/r...mmeracademy/instructors /The Terrost mind.pdf
I think, so far, this view:
has no basis and is, as I already pointed out, naive.
Note I'm not denying that some terrorists do have mental illnesses, especially 'lone wolf' types (and quite frequently recent converts) but to make the above claim for *all* is very silly.
Why? Other than arbitrary legal definitions of a state are they necessarily radically different from soldiers fighting in war? You've not posted anything to differentiate them all certainly not to the point where you can make that claim for all of them. And you've had examples of conventional military forces carrying out mass killings, such as atomic bombings. Are we to assume that all Nazis also suffered from metal illness and perhaps the majority of Soviet troops in WW2... maybe most of the Bosnian Serb forces were mentally ill too in the 90s? Not to mention most men in Sierra Leone, Liberia and Rwanda.
It is very naive to blindly diagnoses 'mental illness' for *all* mass murderers.