ZZL-7 is a fast-acting antidepressant that enhances 5-HT (serotonin) signaling in forebrain circuits. ZZL-7 disrupts the interaction between the 5-HT transporter (SERT) and neuronal nitric oxide synthase (nNOS) in the dorsal raphe nucleus (DRN), which reduces extracellular 5-HT concentration and down-regulates 5-HT1A receptor auto-activity in the DRN. This reduced auto-inhibition enables increase in firing frequency of serotonergic neurons in the DRN and increases in 5-HT release in the medial hippocampus. ZZL-7 can readily cross the blood-brain barrier.