[curryberto]

You can be experiencing full blown mania, and the psychiatrist can give you an anti-psychotic which will bring back to earth in a few hours. Then they can put you on a medication regimen where you stop having manic episodes. I would say it's much further along than doctors in the 1500s.

The mechanisms are not clear, which is not unusual in medicine, but the treatments are very effective.

[loa_in_]

Often the reasoning goes the other way though. We have no idea what's going on but If a patient responded well to antidepressants of all things, that means we diagnose him with depression.