I always thought psychological thrillers were like "Silence of the Lambs", etc. There isn't much going on in the way of psychology in my books, at least not like that.
Maybe to be a little clearer with regards to the philosophy part: In
Spectacle, the thrust of the book is about the nature of truth, and why one should always judge truth for oneself. The protagonist and heroine have been running all over the country trying first to get the truth out and then to escape the antagonist--a man who wants the world kept ignorant and therefore controllable. In
Caldera, it's a matter of trying to save mankind from the eruption of a megavolcano while cutting through government red-tape and fending off enviro-terrorists who think nature should be left alone.
They'd probably be great on the shelves with Crichton's book
State of Fear, but I think that book is still considered a techno-thriller.
Maybe I'm making this harder than it needs to be. (I have a some kind of warped penchant for that.
)