Chronic morphine impairs interoceptive control of avoidance: Implications for dysregulated drug intake.

Interoceptive drug states have been increasingly recognized as important cues that may help regulate intake by disambiguating postintake outcomes. While drug states signaling rewarding or reinforcing effects may occasion drug-taking and drug-seeking, states signaling aversive effects may be critical for terminating a drug-taking episode. Given that drug intake often becomes dysregulated with extensive exposure, the present study investigated whether chronic drug exposure impairs the function of interoceptive drug states to occasion avoidance.