Effects of vasopressin and desmopressin on memory. A double-blind study in 40 healthy volunteers

In a study involving 40 healthy student volunteers, 10 subjects were given lysine vasopressin at a dose of 0.4 ml (23 IU) per day in 3 divided doses for 15 days by the nasal route. Ten subjects were given desmopressin at a dose of 0.2 ml (20 micrograms) per day in a single dose for 15 days by the nasal route. Twenty subjects were given placebo by the nasal route. Memory tests were conducted under the same conditions before and after treatment (verbal span, verbal retention, visual retention, visual learning, verbal learning). Only the contents of the tests were varied, so as to avoid familiarity. Statistical analysis did not show any significant change in the scores between the first and the second series of tests, between the two treated groups, or between them studied separately and the control subjects.