Tritiated LSD binding in frontal cortex in schizophrenia.

It has been reported that the binding of tritiated LSD (at 2 or 4 nm) to frontal cortex is reduced in schizophrenia, a finding that has been interpreted as a reduction in the number of serotonin receptors. The present study, however, reveals in a Scatchard analysis of tritiated LSD binding in frontal cortex in the brains of 13 schizophrenic patients that there was no decrease in binding by comparison with eight control brains. Quantities of neuroleptic remaining in the brain after death cannot be readily washed out and could have led to the previous report of reduced LSD binding. A decrease in affinity of LSD binding sites consistent with this possibility has been demonstrated in chlorpromazine-treated rats. In the brains of five patients who had probably been neuroleptic-free for the year before death, tritiated LSD binding was significantly increased. This result needs to be replicated in larger samples.