Under Baseline (BL) conditions, the target behavior occurs at a high rate, and experimental pain models (Pain) may reduce behavioral rates as a sign of pain-related behavioral depression. Drug-induced relief of pain-depressed behavior (blue) will depend on an interaction between analgesic effects (green), which increase behavioral rate, and motor/cognitive impairment effects (red), which decrease behavioral rate. As drug potency to produce impairment increases (i.e. left shifts in the impairment dose-effect curve), the potential for drug-induced relief of pain-depressed behavior decreases.