I don't know for sure, and I guess every case is different.
I notice that Comprehensive and comprensivo have the same root [1].
Dictionary.com says about Comprehensive [2]:
Origin:
1605–15; < Late Latin comprehēnsīvus. See comprehension, -ive
About comprensivo, La Real Academia Española (RAE) says [3]:
comprensivo, va.
(De comprehensivo).
And when one search comprehensivo [4]:
comprehensivo, va.
(Del lat. comprehensīvus).
In fact, in my mind, their meaning are suspiciously related.
About this, according to The Concise Oxford English Dictionary, 2008, as cited by Wordreference.com, the third definition of Comprehensive is [5]:
▶adjective
1 including or dealing with all or nearly all aspects of something.
■ of large content or scope.
[...]
3 archaic relating to understanding.
While the first meaning of comprensivo (according to the RAE) is [6]:
- adj. Que tiene facultad o capacidad de comprender (‖ entender).
Even further, this makes sense to me since, if I remember correctly, the lating word comprehēnsīvus means something like
to grasp, seize, arrest
To grasp... either an idea, a feeling for another human being, or a situation.
References:
[ 1 ] en.wikipedia.org/wiki/Root_%28philology%29
[ 2 ] dictionary.reference.com/browse/comprehensive
[ 3 ] rae.es/comprensivo
[ 4 ] rae.es/comprehensivo
[ 5 ] www.wordreference.com/definition/Comprehensive
[ 6 ] rae.es/comprensivo
PS. Sorry for the links' format, but I can't post more than 2 links because I need more reputation. :)