How does a psychiatrist infer from an observed condition to a case of mental disorder?

The main thesis of this paper is that mental health practitioners can legitimately infer that a patient's given condition is a case of mental disorder without having diagnosed any specific mental disorder. The article shows how this is justifiable by relying either on psychopathological reasoning, on 'intentional' analysis or possibly on other modes of reasoning. In the end, it highlights the clinical and philosophical consequences of the plurality of modes of 'inferences to mental disorder'.