The group of drugs known as ssris work primarily by interfering with the reabsorption of in the brain.

SSRI stands for Selective Serotonin Reuptake Inhibitor and it is a type of antidepressant medication.  These medications are used to treat depression, and have fewer side effects than other medications. 
These group of drugs works primarily by interfering with the reabsorption of serotonin in the brain. Serotonin is linked to happiness and good feeling, so increased serotonin can help relieve depression.