Amphetamine improves cognitive function in medicated individuals with schizophrenia and in healthy volunteers.
BACKGROUND
Recent research on schizophrenia indicates that cognitive deficits in this illness are important predictors of functional outcome, highlighting the need for treatments that have a positive impact on cognitive function. Here we explore the hypothesis that acute administration of d-amphetamine can improve cognitive function in individuals with schizophrenia who are well-treated with typical antipsychotics, as well as in healthy controls performing under dual task conditions designed to elicit performance deficits analogous to those found in schizophrenia.


METHODS
Ten individuals with schizophrenia taking haldol or prolixin and 22 healthy controls performed spatial working memory, language production, and Stroop tasks under both placebo and 0.25 mg/kg of D-amphetamine.


RESULTS
D-Amphetamine improved reactions times on the spatial working memory and Stroop tasks for both individuals with schizophrenia and controls, and improved working memory accuracy in schizophrenia. In addition, D-amphetamine improved language production for both individuals with schizophrenia and controls.


CONCLUSIONS
These results provide support for the hypothesis that the adjunctive administration of dopamine agonist can improve cognitive in individuals with schizophrenia taking typical antipsychotics. The results are discussed in terms of their implications for understanding the nature of working memory deficits in schizophrenia, and potential future avenues for cognitive enhancement in this illness.
Barch
Deanna M
DM
Department of Psychology, Washington University, St. Louis, MO 63130, United States. dbarch@artsci.wustl.edu
Carter
Cameron S
CS
D000328:Adult; D000661:Amphetamine / Q000627:therapeutic use*; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000627:therapeutic use; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000188:drug therapy / Q000209:etiology; D003710:Demography; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000187:drug effects; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013028:Space Perception / Q000187:drug effects
D014150:Antipsychotic Agents; D000697:Central Nervous System Stimulants; D010919:Placebos; D000661:Amphetamine