CSF homovanillic acid levels showed a significant negative correlation
with ventricle-brain ratios (VBRs) in a group of drug-free chronic
schizophrenic male veterans, while CSF 5-hydroxyindoleacetic acid levels
showed a similar, nearly significant trend. The response of plasma human
growth hormone to 0.75 mg of apomorphine also demonstrated a significant
negative correlation with VBR in this group, but other measures of central
neurotransmitter activity were unrelated to ventricular size.