What is the term for the concept that diseases, in this case psychological disorders, have physical causes that can be diagnosed, treated, and, in most cases, cured, often through treatment in a hospital?

The answer is the medical model.

Explanation:

In psychology, this term explains that mental disorders are the result of physiological factors. Under this model, mental conditions are treated as diseases (i.e. they involve the prescription of medicine).

For example, some studies have shown that disorders such as anxiety and deppresion occur due to chemical imbalances in the brain, which can be regulated through medication.

These powerful political leaders were known as "Political Bosses"

One famous political boss is "Boss" Tweed.

These political bosses would do favors for the ordinary people in order to gain their loyalty. Thanks to journalists in those time, these political bosses were made known to the public and they got to serve time in jail because of their actions.