- If subject is taking an antidepressant drug such as selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), bupropion, tricyclic antidepressants (TCAs), he/she must have been on a stable dose for at least 28 days prior to the Screening Visit and be maintained on that dose for the duration of the trial