Selective Serotonin Reuptake Inhibitors are a class of antidepressants used to treat depression, anxiety disorders and some personality disorders. The brain has neurotransmitters, chemicals that act as messengers. These neurotransmitters are made of serotonin, also known as 5-Hydroxytryptamine or 5-HT, chemicals that naturally occur in the human brain.

Two specific areas of the brain have serotonin concentrations, the midbrain and the hypothalamus. These areas regulate mood, hunger, sleep and aggression. The neurotransmitters are released at one point and absorb at another. This is how the chemical message is emitted and received in the body.

Chemical imbalances of serotonin in these areas cause a variety of mood disorders, particularly depression. SSRI medications prolong or inhibit the process by which serotonin is taken up by neurons, thereby maintaining chemical balance in brain. http://psychcentral.com/lib/2006/choosing-the-best-ssri Inhibiting means stopping or retarding a chemical reaction. SSRI medications treat depression by inhibiting the uptake of serotonin, thus making more available for better brain function. www.answers.com/topic/inhibitor?cat=health

Unfortunately, these medications have side effects. www.holisticonline.com/Remedies/Depression/dep_antidepressant-SSRI.htm Side effects can be perilous for an unborn baby by, for example, damaging the fetal heart.