The main features of the most widely used psychiatric diagnostic systems are briefly presented, namely the last editions of the Diagnostic and Statistical Manual (DSM) of Mental Disorders of the American Psychiatric Association (DSMIII of 1980, DSM-III-R of 1987, DSM-IV of 1994, DSM-IV-TR of 2000, and DSM-5 scheduled for 2013), the 10th edition (1992) of the International Classification of Diseases (ICD-10) of World Health Organization (WHO), and the Psychodynamic Diagnostic Manual (PDM) published in 2006 by the international psychoanalytic community. Regarding DSM-III and DSM-IV, some methodological issues are discussed, namely validity vs. reliability, categories vs. dimensions, and monotethic vs. polytethic system, and some criticisms towards the DSM-5 draft are anticipated. Finally, the following topics are discussed: "descriptive" and "structural" psychopathology; diagnosis as a possible "defense" of the therapist; scientific and philosophical aspects of diagnosis; attempts at "suspending" our judgments and preconceptions; the nomotethic/idiographic dichotomy.
Keywords: Psychiatric diagnosis, Diagnostic and Statistical Manual (DSM), DSM-5, validity, reliability