Subject:
Antipsychotics

Short Description:
Latest CATIE results: Atypicals no better than Trilafon for improving cognition

Background:
One of the final major questions that the NIMH-funded CATIE trials promised to answer was whether atypical antipsychotics are better at improving cognition in schizophrenia than conventional agents, as some smaller studies implied. Patients with schizophrenia were randomly assigned to double blind treatment with Trilafon, Risperdal, Zyprexa, Seroquel, or Geodon. The patients were given neurocognitive testing at baseline and after 2, 6, and 18 months of treatment. Comparing the two scores showed that all treatments produced small neurocognitive improvement, with no significant differences among treatments. However, after 18 months, Trilafon was superior to the other agents in some secondary measures (Keefe R et al., Arch Gen Psychiatry 2007;64:633-647).

TCPR's Take:
This finding is not terribly surprising. The earlier studies showing apparent cognitive superiority of some atypicals used high dose Haldol as the comparator conventional agent, which often requires the use of anticholinergics to quell extrapyramidal side effects. Anticholinergics can cause confusion, which always made Haldol look worse in these studies. This confounding artifact was not present in CATIE, because investigators chose Trilafon, a medium potency drug that rarely requires the addition of anticholinergics.