A study of the statistical reports made by Pollock for the State Hospital Commission shows that during the five years ending on June 30, 1919, dementia praecox constituted 14.42 per cent of the 2,024 voluntary cases admitted to the thirteen New York state hospitals. During a period of eight years ending on June 30, 1919, there were 49,640 first admissions to the New York state hospitals; 12,199, or 24.57 per cent, of these were diagnosed as dementia praecox or conditions allied thereto. The "allied" conditions have not been shown in the New York reports since 1917. In 1918 and 1919 there were 13,588 first admissions, 3,753, or 27.61 per cent, of which were cases of dementia praecox. This would indicate an increase in the incidence of that disease in New York during recent years. The Massachusetts first admissions for 1918 and 1919 show a total of 7,582 cases, 1900, or 25.05 per cent, of which were dementia praecox. It will be noted that the percentage is practically the same as that of New York for the same years. In a group of twenty-one other state hospitals, representing fourteen different states using the Association's classification, 18,336 first admissions have been reported, 3,856, or 21.03 per cent, of which were cases of dementia praecox. This represents a variation from the New York and Massachusetts findings which can be explained on various grounds, largely by the fact that these institutions represent a rural population. We have thus in all 70,987 first admissions to state hospitals, with 16,920 cases of dementia praecox, representing 23.84 per cent of the total number.
A consideration of the different types of this disease as represented by the various state institutions shows somewhat different results. In New York during the years 1916-17-18-19 there were 6,135 cases of dementia praecox shown in the first admissions, classified as follows:—
| Type | Number of Cases | Percentage |
|---|---|---|
| Paranoid | 3579 | 58.34 |
| Catatonic | 468 | 7.63 |
| Hebephrenic | 1463 | 23.84 |
| Simple | 625 | 10.19 |
In Massachusetts in 1917-18-19 there were 2,921 cases, distributed as follows:—
| Paranoid | 1248 | 42.72 |
| Catatonic | 678 | 23.21 |
| Hebephrenic | 828 | 28.34 |
| Simple | 165 | 5.64 |
In a group of nineteen other institutions there were 3,184 cases, as follows:—
| Paranoid | 800 | 25.12 |
| Catatonic | 438 | 10.61 |
| Hebephrenic | 1666 | 52.32 |
| Simple | 230 | 7.22 |
We have thus a total of 12,240 cases, a composite group classified according to types as follows:—
| Paranoid | 5627 | 45.97 |
| Catatonic | 1584 | 12.12 |
| Hebephrenic | 3957 | 32.32 |
| Simple | 1020 | 8.33 |