1933, American English, from escape (n.) in the mental/emotional sense + -ism.
Entries linking to escapism
escape n.
c. 1400, "an act of escaping, action of escaping," also "a possibility of escape," from escape (v.) or from Old French eschap; earlier eschap (c. 1300). Mental/emotional sense is from 1853. From 1810 as "a means of escape." The contractual escape clause recorded by 1939.
-ism
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.