Why aren't dopamine agonists used in treating depression?

With the exception of buproprion which is a lot more noradrenegeric than dopaminergic, there seem (to me) to be almost no dopamine agonists used in the treatment of depression.

I see however that dopamine agonists - as a drug class - exist and are used in the treatment of Parkinsons disease.

Elevating seretonin and norepinephrine seems like a popular approach with SSRIs and SNRIs respectively.

Why is it, then, that dopamine seems to get almost no love from the pharma companies as a therapeutic target in depressed patients?