How do Norepinephrine Dopamine Reuptake Inhibitors (NDRIs) primarily function in mood regulation?

Norepinephrine Dopamine Reuptake Inhibitors (NDRIs) primarily function by inhibiting the reuptake of dopamine and, to a lesser extent, norepinephrine. By blocking the transporters responsible for the reabsorption of dopamine back into the presynaptic neuron, NDRIs increase the levels of dopamine available in the synaptic cleft. This increase in dopamine availability contributes to improved mood and can be effective in treating depressive disorders.

While the correct choice is focused on dopamine reuptake, it's essential to recognize that NDRIs also have some impact on norepinephrine, albeit to a lesser degree. This dual action can contribute to their overall therapeutic effects; however, the primary mechanism is through the inhibition of dopamine reuptake.