The effect of MDMA on motor activity (a), motor disability (b), chorea (c), dystonia (d), and dyskinesia (e) induced by a high dose of l-DOPA (25 mg/kg) in the presence of 12.5 mg/kg carbidopa. Doubling the concentration of l-DOPA did not increase the motor activity significantly but led to a partial reversal of the inhibitory effect of MDMA (12 mg/kg). There was an earlier expression of motor disability and dyskinesia after the doubling of the l-DOPA dose, and a partial reversal of the anti-dyskinetic effect of MDMA.