This paper describes an attempt to demonstrate by discriminant function analysis that psychotic and neurotic depressions are distinct conditions. The analysis was based on a comparison between 63 neurotic depressives and 115 psychotic depressives drawn from four series of consecutive admissions to public mental hospitals in London and New York. The clinical ratings were obtained by standardized interviewing techniques, and the choice of items for discriminant function analysis was based on prior chi-square comparisons between the two populations. In spite of these and other methodological refinements the distribution of the weighted scores of the 178 patients on the discriminant function was unimodal and did not differ significantly from a normal distribution. This finding reinforces the case for replacing the existing categorical classification of depressions by a dimensional classification.