Although there are many reports concerning the endocrinological studies in mental diseases, no general agreement has yet been reached. Investigating the depressive psychosis, the author gave a special consideration to the problem whether there are any specific relations between the urinary corticoid patterns and clinical state. Twenty-four hour urines were collected from 20 males and 20 females, both healthy persons (ranging 22-47 years old in age, the average being adout 25 years) as controls, and 28 cases of depressive psychosis, consisted of 14 males and 14 females (ranging 22-68 years old, 42 years in average) composed of 4 reactive, 2 agitated and 5 brain arteriosclerotic depressive state. Measurements were taken on total neutral 17-ketosteroid (17-KS), total 17-hydroxycorticoid (17-OHCS) and free and conjugated forms of the latter. 17-KS was measured by the modified Holtorff and Koch's method and Bongiovanni's method. The results are as follows: (Every value shows mean and standard deviation). 1. Dialy excretion of total 17-KS in the controls was 7.63±2.71 mg/day for males and 5.67-1,67 mg/day for females. The difference between both sexes is thought to be significant from the statistical standpoint. Daily control excretion of 17-OHCS of males was 6.13±1.74 mg/day as the total amount, 0.88±0.51 mg/day as free form, 5.26±1.57 mg/day as conjugated form, 8.12±4.95 as the ratio of conjugated form/free form (C/F), and 86.18±6.28 as the percentage of conjugated form/total (C/T%); that of females was 5.48±2.07 mg/day as total, 0.65±0.42 mg/day as free form, 4.83±1.84 mg/day as conjugated form, 9.50±4.85 as C/F and 88.06±5.87 as C/T%. The difference between sexes appears to be insignificant. 2. Depressive group: Total 17-KS was 5.42±2.83 mg/day for males and 4.97±2.05 mg/day for females, being lower than normal value, and the former was significant but the latter insignificant from the statistical standpoint. Total 17-OHCS was 5.42±2.86 mg/day for males and 3.83±1.68 mg/day for females, being lower than normal value, which means that the former is insignificant while the latter significant. Free 17-OHCS was 2.17±1.18 mg/day for males and 1.19±0.82 mg/day for females, 2 times or more than normal value, and those of both sexes were significant. Conjugated 17 OHCS was 3.25±1.90 mg/day for males and 2.64±1.92 mg/day for females, lower than normal value, being significant for both sexes. 3. In comparing all the depressive groups with small groups of 2 agitated, 4 reactive and 5 cerebral arteriosclerotic depressives, there were no significant differences but the two agitated in the small groups showed the lowest values of all the depressives, namely, total 17-KS, total 17-OHCS, conjugated from and C/F ratio all proved to be much lower than those in the other depressives. 4. Total 17-OHCS values of 5 cases after treatment were found to have been increased, free 17-OHCS decreased, and conjugated form increased. As the result of the increase in the C/F and C/T % , the corticoid patterns approached the normal. 5. The author investigated the relation of corticoid patterns and liver dysfunction, then depressive psychosis and schizophrenia. Incomparing schrzophrenia with depressive psychosis, 17-KS value of the latter was found to approximate that of acute schizophrenics and total 17-OHCS value of the latter to that of chronic schizophrenics in both sexes. From these findings it seems that depressive psychosis indicates the diencephalo-pituitary-adrenccortical dysfunction more significantly than schizophrenia.