Several authors made important contributions to the evolution of psychopathological concepts that we now often gather under the topic of formal thought disorders (FTD).

Our objectives were to describe the interpretation of concepts - including FTD and related concepts - by authors that had a major impact in the field and in defining trends nowadays.

In general we aimed to reach a comprehensive understanding of the evolution of the above mentioned.

We reviewed the literature by searching PUBMED and a library database using the terms thought and language and association and schizophrenia and course interchangeably. We used article and book references to increase our search.

Throughout the years - from the first observations suggesting a primary pathology of the ability to coordinate ideas of Esquirol and Guislain to the current DSM-IV Schizophrenia criteria - and considering authors from all over the world - including Fish (UK), Kurt Goldstein, Carl Schneider, Emil Kraepelin (Germany), Eugen Bleuler (Switzerland), Jules Séglas (France), Nancy C. Andreasen (USA), Pio de Abreu (Portugal), Elie Cheniaux (Brazil), among others - terms have been given approximate meanings and different symptoms/signs have been considered to that purpose.

Using precise concepts of formal thought and related disorders is crucial when considering diagnostic hypothesis and passing information on to colleagues. Thus, it is of utmost importance having a better understanding of the above.