Of course the not so hidden agenda of the "Psychiatrists....defining new disorders and creating more and more subcategories..." is absurd.
But regarding anger, in a wierd sort of way, the classical chinese references on health actually agree it is an illness. Within the 5 organ system, anger is associated with an energy imbalance within the liver energy system and as such, expressions of anger are deemed to be a manifestation of that illness. Some beleive expressing anger will harm the liver. But they go a step further and say if you are expressing anger it is because you are already ill. Physically. Of course they are not making millions on drug sales but are promoting qi gong movements, meditations and herbs that are probably growing in your yard already (dandelion and chicory anyone?).
As an aside, it is noteworthy how the pysch industry successfully hijacked the realm of what prior to implementing their strategy was firmly in the spiritual domain. Now you need a highly paid doctor instead of a "priest".