High fever doesn't cause influenza. But doctors still treat high fever in influenza patients because high fever can cause life-threatening problems.

Whether or not low serotonin levels cause clinical depression, low serotonin levels cause significant health problems and suffering, sometimes to the point of self-destructive behavior and even suicide. Treating low serotonin levels can be very important for quality of life and health – even if the low levels are a symptom and not the underlying cause.

Back when there was no treatment for HIV, a fungal infection called thrush plagued many AIDS patients, causing a lot of mouth and throat pain and preventing them from eating.

Nobody thought the fungus that caused thrush caused AIDS. Everybody thought the fungus should be treated with medication.

I don't guess this is such a difficult concept. I also don't guess Matt Walsh really has such a hard time understanding it. His whole career is based on saying outrageous things that get attention.

Much of the political right in the United States seems to be about that right now.

I suppose it's because they don't have much else to sell to the public.