The Minnesota Percepto-Diagnostic Test and presenile dementia.

The records of psychiatric patients seen for clinical reasons were used to examine the discriminating capacity of the rotation score of the Minnesota Percepto-Diagnostic Test. Thirty-one patients with an eventual organic diagnosis were compared with a matched group with functional diagnoses. The main organic subgroup, 17 patients diagnosed as presenile dementia, had markedly raised rotation scores, while the remaining 14 of mixed diagnoses did not differ from their controls. This high rotation in presenile dementia is in striking contrast to the moderate rotation shown by patients with Korsakov's psychosis in a recent study by Helmes, Holden, and Howe. It is suggested that this reflects the differing pathology of the two conditions.