Every sound the child hears uncorrected is muffled.

Scientists must follow a path that is not scientifically predefined, and that requires decisions at every step. Whether they are right or wrong becomes clear in retrospect, which is why errors are unavoidable (though they should not be left uncorrected for long).

Over time, if uncorrected, major depression can cause such conditions as progressive mineral loss from bones, accumulation of abdominal fat, increased blood platelet reactivity, and increased risk of cardiovascular disease. Moreover, certain types of antidepressants may contribute to some of these conditions.