Wrong. MDMA, or ecstasy, was being tested for potential effects on age-related dementia (distinct from Alzheimer's). I did some of that work several years ago. It acts on both Dopamine and serotonin, but far more on serotonin than does its relative, methamphetamine. The mechanism of action is to release the transmitter from the neuron terminal, and to prevent reuptake, which is definitely what you don't want in Parkinson's disease (PD).
PD is a condition that arises from rapid attrition (die-off) of the population of dopamine neurons originating in the substantia nigra and projecting to the basal ganglia. Other DA systems are affected as well, but less dramatically and overtly than the extrapyramidal system represented by the foregoing. L-DOPA is a dopamine precursor, so in a climate of fewer dopamine cells the basic raw material is provided by the medication. Only one further metabolic step is required to convert L-DOPA to dopamine, in other words. You don't want a drug, such as MA or MDMA, that further depletes the cell populations of their substrate.