The novelty oddball task was administered during a pretreatment session before patients received medication. Patients were unmedicated a minimum of 7 days before testing, although most patients were drug-free for a considerably longer period or were not previously treated with an antidepressant. No patient was tested within 6 weeks of receiving fluoxetine or 1 week of receiving other antidepressants and no patient had received a monoamine oxidase inhibitor.
