1
general::
Phrase(s): *possessed by something
obsessed or driven by something. (*Typically: be ~; become ~.) • Ned was possessed by a desire to become the best at everything he did. • Jan acts as if she is possessed by the need to be right all the time.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Driven by, obsessed with, as in He was possessed by the idea of becoming a millionaire. This idiom employs possess in the sense of "dominate one's thoughts or ideas," a usage dating from the late 1500s.
American Heritage Idioms