We do!
For Parkinson’s (lack of dopamine in certain parts of the brain) we give oral L-dopa (a precursor of dopamine)
For depression, bupropion (Wellbutrin) is a very commonly used dopiminergic agent that works via reducing pre-synaptic dopamine reuptake (like many other anti depressants do for serotonin).
Substances of abuse, namely cocaine and stimulants, also work to increase the amount of dopamine in various synapses.
Latest Answers