Urinary cyclic AMP in relation to lithium treatment in manic-depressive illness

Urnary cyclic AMP was measured longitudinally in six patients with bipolar affective disorder. The values varied from 3.55 to 19.0 mugmol/24 hours with considerable variation between subjects. Three of these patients improved with administration of lithium carbonate. This improvement was not correlated with a change in cyclic AMP excretion. Five normal male volunteers were studied over a 5-day period. The urinary excretion for this group showed the same large intersubject variability but smaller intrasubject variation as was found for the patient group. It is suggested that erroneous results may be obtained for urinary cyclic AMP excretion if mean group values are used from patients not studied longitudinally.