Continuous (CONT-HAL), but not chronic and intermittent (INT-HAL) haloperidol (HAL), treatment enhances the locomotor response to amphetamine (1.5 mg/kg). n's=14 per condition. CONT-HAL, group receiving 0.5 mg/kg/day haloperidol through minipump; INT-HAL, group receiving 0.05 mg/kg/day haloperidol through daily subcutaneous injection. *p<0.05 compared with vehicle (VEH). AMPH, amphetamine.