<human>: Is it true that the human body has a natural antidepressant?
<bot>: Yes, the human body has a natural antidepressant. Serotonin is a neurotransmitter in the brain which helps to regulate mood and emotions. Low levels of serotonin can cause depression. Antidepressants are drugs designed to increase the amount of serotonin in the brain. So the human body has a natural antidepressant.