Mindkiller

Description for MINDKILLER by Spider Robinson:

Mindkiller: Wireheads, addicted to an electric current fed into the pleasure centers of the brain, are the new junkies. Karen, a former wirehead who barely escaped death by pleasure, is determined to bring down those who sell the wireheading equipment, but she and her lover Joe instead turn up evidence of a shadowy global conspiracy—not to control the world, but to keep anyone from realizing that the masters of mind control have been controlling us all for some time now . . . .

This is #1 in Lifehouse Trilogy.