Sentence memory affected by vasopressin analog (DDAVP) in cross-over experiment.

DDAVP has been shown to facilitate memory, especially retrieval, in humans. Healthy young male adult subjects received DDAVP (60 micrograms) in a cross-over design with a one-week interval between sessions. Results indicated that DDAVP improved immediate memory during the first but not the second testing session, particularly for low-verbal subjects. Treatment with DDAVP also facilitated delayed (one-week) recall in the opposite group, a cross-over interaction that suggests a retrieval locus for the DDAVP effect. Furthermore, since DDAVP improved immediate memory more for low-verbal subjects and delayed memory more for high-verbal subjects, it appears that individual difference factors will be important in understanding the effects of vasopressin on memory.