We all know first hand that mental anguish exists and that at least a hug or an hour of someone listening to you offers relief. Beyond that, knowledge in the field is clouded by entrenched interest groups each preaching the solutions they find most profitable. Rigorously applying the scientific method is the only way forward.
The latest edition of DSM, the influential American dictionary of psychiatry, says that shyness in children, depression after bereavement, even internet addiction can be classified as mental disorders. It has provoked a professional backlash, with some questioning the alleged role of vested interests in diagnosis.