AMPLITUDE INTENSITY FUNCTIONS OF AUDITORY EVENT-RELATED POTENTIALS PREDICT RESPONSIVENESS TO BUPROPION IN MAJOR DEPRESSIVE/

Patients diagnosed with major depressive disorder (MDD) and enrolled i n an open-label safety surveillance study of a sustained release formu lation of bupropion hydrochloride (100 to 300 mg/day) were evaluated w ith the Hamilton Rating Scale for Depression (HAM-D) immediately befor e and 6 to 12 weeks after the initiation of drug treatment. Auditory e vent-related potentials (ERPs) recorded under a stimulus intensity mod ulation paradigm were also obtained at these times. Patients were clas sified as responders and nonresponders based on post-treatment HAM-D s cores, with responders having HAM-D scores less than 10 and nonrespond ers having scores greater than 10. Consistent with our previous findin gs, responders exhibited significantly larger positive slope coefficie nts for P2 ERP component amplitudes as a function of auditory stimulus intensity obtained at baseline and were not affected by bupropion tre atment. Thus, these results further support our previous finding that ERP amplitude/intensity functions measured under a stimulus intensity modulation paradigm provide information about the likelihood of a posi tive therapeutic response to antidepressant pharmacotherapy in patient s with MDD and extends these results to bupropion, a pharmacologically atypical antidepressant agent.