Some psychiatrists believe embitterment is so common and so destructive that it should be classed as a mental illness, the Los Angeles Times reports. Sufferers are described as people who have worked hard at something like a job or relationship, only to be transformed into angry, pessimistic, brooding individuals consumed by thoughts of revenge when their efforts fail.
"They feel the world has treated them unfairly. It's one step more complex than anger, " said a German psychiatrist who labels the condition "post-traumatic embitterment disorder." He warns that such individuals are extremely unlikely to seek treatment, and said he believes the condition explains many instances where individuals thought of as normal turn into mass killers.