WHILE the literature on senescent decline and problems associated with old age is voluminous (17,21,30), little attention has been paid to the non-dementing psychoses of old age (18, 32). Toxic disorders, early cases of cerebral arteriosclerosis, and in particular the functional disorders of old age, are amenable to treatment, and in general respond more favourably than the senile dementias, where the course is usually one of progressive deterioration. Although he was stressing a broad relationship of age to recovery from psychosis, Clow (as reviewed by Granick, 22) was nonetheless able to state of individuals over 60 years of age: "The organic disturbances showed little improvement, but the functional disorders, particularly the manic-depressives, tended to recover." Not only do they recover following electro-shock treatment and other forms of therapy, but a significant number recover spontaneously. Since these nosological entities are comparable in age, the different response to treatment, or rather the general failure to respond favourably in senile dementia, does not seem purely attributable to the state of old age.In spite of the absence of clear-cut qualitative neuro-anatomical differences in the brain between normal old age and senile dementia, most authorities hold to the view that further research will demonstrate an essential difference between the two states, and that the dementia may be due to a disease process (4, pp. 212-214; 26, pp. 1100-1105; 29, pp. 88-90; 38, pp. 597-599, 40). Runge (38) states that on the basis of evidence to date we are obliged to accept the findings that in senile dementia there is a distinct increase in anatomical changes of a type similar to those found in the brains of normal old people, but that no qualitative differences in this respect have been demonstrated.Neither does the electroencephalograph appear to offer any clear-cut distinction between aging and dementia (10, p. 263). The biochemical studies of Lovett Doust et cd. (31), however, show that the extent of senile dementia exists physiologically along a spectrum of progressive