OBJECTIVE: Pediatric studies of cerebrospinal fluid (CSF) monoamine
metabolites in childhood-onset schizophrenia may help to elucidate both
pathophysiology and treatment response in early-onset psychosis. METHOD:
CSF homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5- HIAA), and
3-methoxy-4-hydroxyphenylglycol (MHPG) and serum prolactin were measured
during drug-free and antipsychotic medication conditions in 18 patients
(mean age = 14.2 years, SD = 1.7) who had onset of schizophrenia by age 12
(mean age at onset = 9.9 years, SD = 1.8). Relationships between changes in
CSF monoamines and serum prolactin and clinical outcome were examined, and
the degree of change in CSF monoamines in response to clozapine treatment
was compared with that for 16 patients with later-onset schizophrenia.
RESULTS: Despite patients' significant clinical improvement with treatment,
CSF monoamine concentrations and ratios of HVA/5-HIAA and HVA/MHPG did not
significantly change with 6 weeks of either haloperidol or clozapine
treatment. Serum prolactin levels increased during haloperidol treatment.
Clozapine had similar effects on CSF monoamines in patients with childhood-
and later-onset schizophrenia. CONCLUSIONS: While these data are compatible
with continuity between childhood- and later-onset schizophrenia, they also
highlight the complexity of the biochemical events mediating clinical
changes in schizophrenia.