As the National Alliance for Research on Schizophrenia & Depression in Great Neck, N.Y., pointed out, mood disorders are caused by a flaw in chemistry, not character. That’s why medications that alter brain chemistry play a large role in psychiatric treatment.
There are now five prescription drugs in the class known as selective serotonin reuptake inhibitors (SSRIs) approved in the United States for the treatment of depression, obsessive-compulsive disorders, bulimia nervosa, anxiety, panic disorder and other medical conditions such as PMS.
This raises the question: Does any member of the class provide better symptom relief or reduce serious or long-lasting side effects in treating these conditions?
James L. Smith, a 40-year-old high school teacher in Pontiac, Mich., has experienced bouts of depression since he completed college in the mid-1980s. His family doctor initially prescribed a tricyclic antidepressant for him, but he found its side effects troublesome. “The medication made me tired and I had a difficult time sleeping,” he said. “Basically, I just stopped taking it after about three months. I decided I’d rather live with the depression.”
By the time James sought help a second time, SSRIs had become available. “The psychiatrist I saw explained there was a whole new group of medications that were very good,” Smith said. “If one didn’t help after several months, he would prescribe another one. I assumed that meant they weren’t identical; that one might work better than another for me. But that wasn’t necessary. The first SSRI prescribed has worked well for more than five years.”
How Do Antidepressants Work?
According to the Encyclopedia Britannica, serotonin — also known as 5-Hydroxytryptamine or 5-HT — is a chemical that naturally occurs in the human brain, intestines, blood platelets and mast cells. Interestingly, it is also a component of many toxic venoms, including those of the wasp and some poisonous toads.
The chemical is derived from tryptophan, a natural amino acid. As a neurotransmitter, one of serotonin’s most important functions is the transmission of impulses across synapses, the space between neurons or nerve cells.
Typically serotonin is concentrated in two specific areas of the brain: the midbrain and the hypothalamus. These areas are responsible for regulating mood, hunger, sleep and aggression. Changes in the concentration of serotonin in these areas are linked to a variety of mood disorders, particularly depression.
Serotonin levels are thought to be reduced to below optimal levels when it is returned (or taken up) too quickly or in too great a quantity by neurons after the chemical has transmitted an impulse across a synapse.
All SSRI medications function by prolonging (or inhibiting) the process by which serotonin is taken up by neurons (the process referred to as “reuptake”). All SSRIs are designed to prolong the reuptake process only for serotonin. To differentiate between serotonin and a host of other chemicals in the brain, they must be highly selective.