Many cases which were originally diagnosed as manic-depressives were subsequently reclassified as schizophrenia.Review of New York State and Federal statistics for other states show:(a) Marked fluctuation in the number of manic-depressives as compared with dementia præcox and in relation to total admissions.A complete reversal of the general trend in some states.Special case studies reveal that errors in diagnosis result from the failure to apply the established criteria of symptomatology.A need for periodic reconsideration of diagnosis is indicated.Abstract Teaser