THE LEVEL AND DIURNAL RHYTHM OF SERUM SEROTONIN IN MANIC-DEPPESSIVE PATIENTS

Abstract

The serum levels and diurnal rhythm of serotonin before and during treatment were investigated in 65 manic-depressive patients, comparing with those in 34 normal controls and 13 schizophrenics. 1. The serum serotonin level in 40 newly admitted depressive patients who had not been medicated (127±58 ng/ml) was significantly lower than that in normal controls (221±96ng/ml). 2. The serum serotonin level in 24 recovering patients with depression had the tendency to return to normal while under treatment with imipramine type antidepressants (281±189 ng/ml). 3. The serum serotonin level in 10 manic patients (365±85 ng/ml) was significantly higher than that in normal controls. 4. After the injection of imipramine to depressive patients, serum serotonin level tended to increase (1.5 times). 5. Electroconvulsive shock did not appear to alter the serum serotonin level in depressive patients and normal dogs. 6. As for the diurnal rhythm of serum serotonin of depressive patients, the serotonin level in the morning was the lowest, which seemed to be related to the worst depressed mood in the morning. In the manic patients, the serotonin level at 20.00 hours was the highest. This pattern of rhythm resembled that of normal controls. 7. The significance of serum serotonin levels in manic-depressive patients was discussed.