The Biases of Psychiatric Diagnosis

Psychiatric diagnosis tests the hypothesis that particular signs and symptoms, when regularly found together, belong to a particular class. The class concerned, in turn, is usually part of a taxonomic system, and which system one chooses will depend on the aim and function of diagnosis (treatment, research, administration, etc.). Diagnosis and classification involve a loss of information, the magnitude of which is determined by both the use to which the diagnosis has been put and the assumptions and theoretical orientation of the clinicians involved in the exercise.