"He just had a nervous breakdown." We hear it all the time. But what does it mean? "Nervous breakdown" is not a clinical diagnosis. But it is a way of explaining that your life has become completely unmanageable. Typically when you have what is described as a nervous breakdown, you cannot function in any of the normal routines of daily life. You miss work, or you do the job very badly. You may have long crying jags, frequent irrational rages, or episodes in which you go on buying binges, abruptly abandon family or simply talk utter nonsense. You may also be homicidal, suicidal or self-harming in other ways.