The neurocognitive effects of low-dose haloperidol: a two-year comparison with risperidone.
BACKGROUND
Neurocognitive deficits are core features of schizophrenia that are linked to functional outcome for the disorder. Recent studies and reviews have concluded that newer antipsychotic medications are better for neurocognitive deficits than conventional antipsychotic medications; however, one difficulty in interpreting this literature is that the comparisons have mainly been with high doses of conventional medications. This study examined the neurocognitive effects of low-dose haloperidol compared with risperidone over a 2-year period.


METHODS
Sixty-two patients were randomly assigned to medication (starting at 6 mg of each medication) and administered neurocognitive batteries six times over the course of follow-up. At 6 months, the mean dose of haloperidol was 5.0 mg, and the mean dose of risperidone was 6.0 mg. Neurocognitive data were reduced into cluster scores and a global summary score.


RESULTS
We found no significant overall differences in treatment effects on the cluster scores or the global score. The global score revealed a significant group by time interaction, reflecting the fact that the haloperidol group tended to improve initially and then stay stable, whereas the risperidone group improved more gradually over the follow-up period.


CONCLUSIONS
This study did not provide support for neurocognitive advantages of a newer antipsychotic medication over a low-dose conventional medication. We speculate that conventional medications may have neurocognitive benefits at low doses that are neutralized or reversed at higher doses.
Green
Michael F
MF
Veterans Affairs VISN 22 Mental Illness Research Education and Clinical Center, Los Angeles, California, USA.
Marder
Stephen R
SR
Glynn
Shirley M
SM
McGurk
Susan R
SR
Wirshing
William C
WC
Wirshing
Donna A
DA
Liberman
Robert P
RP
Mintz
Jim
J
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006220:Haloperidol / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D018967:Risperidone / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents; D006220:Haloperidol; D018967:Risperidone