Cerebrospinal fluid concentrations of free GABA in schizophrenia: no changes after haloperidol treatment.

The concentrations of free GABA were determined in the cerebrospinal fluid of 19 paranoid schizophrenic patients before and after 3 weeks on haloperidol treatment. No significant effect of the neuroleptic treatment on the CSF free GABA concentrations was detected. Furthermore, no correlations were found between changes in GABA concentrations and psychopathological improvement on the Brief Psychiatric Rating Scale. These negative findings are at variance with earlier reports of increased or decreased CSF GABA concentrations after neuroleptics and suggest that subtle changes of the amino acid concentrations in the brain might not be faithfully reflected in the concentrations of its free fraction in the cerebrospinal fluid.