Procedural learning in schizophrenia can reflect the pharmacologic properties of the antipsychotic treatments.
BACKGROUND
Conventional and atypical antipsychotics have different affinities for D2 receptors, and these receptors are principally located in the striatum. Given that this cerebral structure was previously found to play a major role in procedural learning, the antipsychotic treatment in schizophrenia may be determinant for the procedural learning profile of these patients.


OBJECTIVE
The current study was aimed at verifying whether procedural learning differs in patients with schizophrenia treated with conventional antipsychotics and patients treated with atypical antipsychotics.


METHODS
Forty-five patients with schizophrenia were divided into 3 different groups according to their pharmacologic treatment: (1) haloperidol, a classical neuroleptic with high D2 receptor affinity; (2) clozapine, an atypical neuroleptic with practically no D2 receptor affinity; and (3) risperidone, an atypical neuroleptic that nevertheless shows high D2 receptor affinity. Patients were compared to 35 control subjects on a visuomotor procedural learning task (mirror drawing).


RESULTS
All patients were able to learn the task. However, those treated with haloperidol showed some degree of learning impairment, while those treated with clozapine or risperidone did not show this impairment. In addition, performance per se, regardless of the learning, was found to be affected in the haloperidol and risperidone, but not in the clozapine groups.


CONCLUSIONS
Procedural learning in schizophrenia may be differentially affected, depending on the pharmacologic profiles of the antipsychotics used for the treatment of this illness.
Scherer
Hélène
H
Cognitive Neuroscience Center, Université du Québec à Montréal, Canada.
Bedard
Marc-André
MA
Stip
Emmanuel
E
Paquet
François
F
Richer
François
F
Bériault
Maxine
M
Rodriguez
Jean-Pierre
JP
Motard
Jean-Pierre
JP
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000494:pharmacology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007858:Learning; D007859:Learning Disabilities / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D017448:Receptors, Dopamine D2 / Q000187:drug effects; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents; D017448:Receptors, Dopamine D2