Cognitively healthy elderly people maintain stable cognitive performance when measured longitudinally by both careful clinical evaluation and repeated psychometric testing. This stability is maintained unless and until they develop a dementing illness, at which time a sharp decline in performance is observed.

No abstract

Guanosine 3',5' cyclic monophosphate (cyclic GMP) levels in incubated slices of mouse cerebellum are increased 10-fold by glutamate and two-to three-fold by glycine or y-aminobutyric acid (GABA). Glutamate also produces a 10-fold increase in adenosine 3',5' cyclic monophosphate (cyclic AMP) in the same tissue. However, GABA decreases cyclic AMP levels 30-40 per cent, and glycine produces only a transient 50 per cent accumulation of this cyclic nucleotide. Theophylline slightly augments the accumulation of cyclic G M P produced by all three amino acids but markedly attenuates the accumulation of cyclic AMP produced by glutamate. In the absence of CaZf, none of the three amino acids has any effect on cyclic G M P levels, and glutamate produces only a 50 per cent rise in cyclic AMP levels. The decrease of cyclic AMP levels produced by GABA is not affected by theophylline or by the absence of CaZ+. These data suggest an involvement of both cyclic G M P and cyclic AMP in the neurochemical actions of glutamate, GABA and glycine.

Clinically significant depressive symptoms may be common in individuals with very mild or mild DAT, although they may fluctuate. Information from both a knowledgeable collateral source and the participant is important for detection of depressive symptoms.

Both the Geriatric Depression Scale (J. A. Yesavage et al., 1983) and the Beck Depression Inventory (A. T. Beck, A. J. Rush, B. F. Shaw, & G. Emery, 1979) were less effective in identifying depressed men than women in a sample of 191 geriatric psychiatric inpatients with major unipolar depression. From one quarter to one half of the men were missed cases, depending on the cutoff score used. Separate cutoff scores for older men and women on depression screening instruments may be appropriate.