Antidepressants like Wellbutrin (bupropion) and SSRIs like Prozac and Zoloft can increase dopamine and serotonin levels by raising their tonic (baseline) levels.

“So, certain drugs like antidepressants, like Wellbutrin, bupropion, as it's commonly called, or the so-called SSRIs, the serotonin selective re- top- reuptake inhibitors, excuse me, like Prozac, Zoloft, and similar, will increase dopamine and serotonin respectively. They're not increasing the peaks in those molecules, the, what we call the acute release of those molecules. What they're doing is they're raising the overall levels of those molecules. They're raising the sort of foundation or the tide, if you will.”