Psychomotor and memory effects of haloperidol, olanzapine, and paroxetine in healthy subjects after short-term administration.
BACKGROUND
Impaired psychomotor function has been shown to be associated with clinical and functional outcome in schizophrenia. However, few studies have investigated the short-term effects of antipsychotics on the cognitive and psychomotor functions of this patient group. Because many confounding factors tend to influence the test results in patient research, this study investigates the drugs' effects in healthy volunteers.


OBJECTIVE
The short-term effects of haloperidol (2.5 mg), olanzapine (10 mg), and paroxetine (20 mg) on psychomotor function in 15 healthy volunteers are compared with placebo and each other.


METHODS
In a crossover design, the subjects completed a battery of psychomotor tasks assessing psychomotor speed, sensorimotor accuracy, visuospatial monitoring, and speed of information processing. In addition, peak velocity of saccadic eye movements and subscales of the visual analog scales were analyzed as the objective and subjective measures for sedation, respectively. Finally, the verbal memory test was used to assess the drugs' effects on memory.


RESULTS
Apart from affecting the pursuit task where visuospatial monitoring, sensorimotor speed, and sensorimotor accuracy are measured simultaneously, haloperidol has been proven to be not associated with sedative nor with impairing effects on psychomotor function or verbal memory. In contrast, olanzapine had significant sedative effects. Moreover, the subjects displayed a significant impairment on all measures of psychomotor function and verbal memory, which was not attributable to the drug's sedative effects. After administration of paroxetine, no effects were found, with the exception of a single improvement in eye movement velocity.


CONCLUSIONS
Short-term administration of olanzapine, and not of haloperidol, impedes several aspects of psychomotor function and verbal memory in healthy volunteers.
Morrens
Manuel
M
Collaborative Antwerp Psychiatric Research Institute, Antwerp, Belgium. mmorrens@hotmail.com
Wezenberg
Elke
E
Verkes
Robert Jan
RJ
Hulstijn
Wouter
W
Ruigt
Ge S F
GS
Sabbe
Bernard G C
BG
D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001569:Benzodiazepines / Q000008:administration & dosage / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D000077152:Olanzapine; D017374:Paroxetine / Q000008:administration & dosage / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D012016:Reference Values
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D017374:Paroxetine; D006220:Haloperidol; D000077152:Olanzapine