In this group should be included cases in which a satisfactory diagnosis cannot be made and the psychosis must therefore be regarded as an unclassified one. The difficulty may be due to lack of information or inaccessibility of the patient; or the clinical picture may be obscure, the etiology unknown, or the symptoms unusual. Cases placed in this group during the year should be again reviewed before the annual diagnostic tables are completed.

Cases of the type formerly placed in one of the allied groups should not be put in the undiagnosed group except for some special reason. Most of the cases hitherto called allied should be placed in the main group to which they seem most closely related.