5-Hydroxyindoleacetic acid (5 HIAA) and homovanillic acid (HVA) following probenecid in acute psychotic patients treated with phenothiazines

Lumbar CSF 5 HIAA and HVA were measured following probenecid administration in acute psychotic patients before and during treatment with phenothiazines. Patients with more classical schizophrenic symptoms had higher values for 5 HIAA/HVA than other psychotics, depressives, and inmate volunteers. Prior to treatment CSF 5 HIAA, but not HVA, correlated significantly with several clinical items related to psychotic disorganization. Phenothiazine treatment produced significant increases in CSF HVA which could not be correlated with the dose of antipsychotic or antiparkinson drugs.