Why do labels make us think we know something?

During the course of one routine lecture hour in 1971, a student recommended
drugs as the best treatment for a woman's "chronic, severe depression." The
New York Times Magazine was there to record the subsequent scene, which
Szasz has spent the majority of his career reproducing:

"So you would treat this 'sickness' she's got with drugs?" There are several
uncomfortable, uncomprehending laughs from around the
room. "But what, exactly, are you treating? Is feeling miserable-and needing
someone to talk things over with-a form of medical illness?"
Szasz gets to his feet, walks over to a blackboard and picks up a piece of
chalk.

"I don't understand-we're just trying to arrive at a diagnosis," protests
the student, his voice confused.

"Of what?" demands Szasz. "Has she got an illness called depression, or has
she got a lot of problems and troubles which make her unhappy?"
He turns and writes in large block letters: "depression." And underneath
that: "unhappy human being." "Tell me," he says, facing the class, "does the
psychiatric term say more than the simple descriptive phrase? Does it do
anything other than turn a 'person' with problems into a 'patient' with a
sickness?" He puts down the chalk so hard that a cloud of dust rises. There
is a low muttering among the students as he returns to his seat.