We know when we're sad. We don't need the dictionary definition of depression, "a mental state characterized by a pessimistic sense of inadequacy and a despondent lack of activity" to explain the condition. But when it is truly an illness, not just a passing emotion, doctors do a complete physiological evaluation to determine the extent of the problem, whether it is a mild case of depression or an extreme condition that would require depression rehabilitation. We are fortunate in this century, that getting help for depression no longer means getting shock treatments or a frontal lobotomy. The father of the lobotomy "Walter Freeman believed lobotomies worked because the procedure severed connections between the frontal lobes of the brain and the thalamus, thought to be the seat of human emotion, which the mentally ill apparently had in overabundance. "