European long-term followup studies of schizophrenia.

This article focuses on the variability of diagnostic concepts and their impact on the results of European followup studies. Continental European and Scandinavian definitions of schizophrenia are considered along with other factors such as age of onset, change of symptoms with time, development of defects, the effects of aging, treatment, and study methodology. The concepts of schizophrenia are regarded as too diverse to allow meaningful comparisons of course and outcome among studies. Multiaxial or multidimensional description of patients offers a solution to this conundrum.