ABSTRACT Introduction: For a significant number of patients with depression, current antidepressants – such as selective-serotonin uptake inhibitors (SSRIs) - are ineffective. However, evidence from animal models suggests that 5HT4 agonism may be able to effectively augment SSRI treatment. To explore the potential antidepressant augmentation effect of PF-04995274 - a novel, highly-selective 5-HT...