Cerebrospinal fluid and plasma monoamines and their metabolites in euthymic bipolar patients.

In a search for trait markers in manic-depressive illness, we studied cerebrospinal fluid (CSF) and plasma monoamines and their metabolites in 25 lithium-treated euthymic bipolar patients (12 of whom provided unmedicated samples) and 30 normal volunteers. No group differences were found. Lithium treatment showed a trend to increase CSF hydroxy-indoleacetic acid (HIAA) (p = 0.05). Dopaminergic and serotonergic metabolites were highly correlated in the CSF of all three groups. We found no evidence of a trait marker for manic-depressive illness among CSF monoamines and their metabolites.