I know that aromatic rings exhibit diamagnetic ring currents which causes the protons outside the ring to go downfield in H-NMR. Antiaromatic compounds exhibit paramagnetic ring currents which have the opposite effect. How does the difference in two electrons between aromatic and antiaromatic systems cause such a dramatic shift in the properties of the ring current? Why does diamagnetic current induce a downfield while the paramagnetic current induces an upfield shift?
I've found this question: Ring currents of anti-aromatic and aromatic systems but the answer doesn't address how the different currents give rise to different effects in H-NMR.