Miracle Drug, Poison or Placebo? (Part II)

Continuing an article by Maia Szalavitz for MSN Health & Fitness, Part II:



A Complex Challenge: Finding the Right Drug


So, how can you find an antidepressant that will work, not make you feel worse? That’s the billion dollar question that pharmaceutical companies, psychiatrists and researchers are racing to answer.


The complexities, however, are daunting. A large proportion of human genes code for brain development and function, and they interact in complex ways not only with each other, but with environmental influences like stress, parenting and social support.


One intriguing study by Tranter and colleagues involved giving antidepressants to healthy people. The study compared the results of a drug similar to Prozac, which affects the serotonin system in the brain, to the effects of another drug, which affects the norepinephrine system.
Serotonin—a neurotransmitter that sends messages from one brain cell to another—is involved with regulating mood. Norepinephrine (also called noradrenaline) helps mediate attention and the brain’s response to stress. The antidepressants in the study affect these transmitters by keeping them activated for longer than usual.


“One of the effects of [the Prozac-like drug] was what you might call a ‘serenic’ effect,” Tranter says. “It’s this feeling of being aware of stressful things going on, but they don’t bother you much.”


Some people liked this effect—as did the people around them, who found them easier to get along with. Others, however, reported this same experience, but found it unpleasant. “They felt disconnected from their emotions, unpleasantly numb, and they didn’t like it at all,” Tranter says.


The participants in Tranter’s study had been given personality tests beforehand. Some of the traits measured on these tests are strongly influenced by genetics, reflecting inborn temperamental differences.


People who liked one of the drugs tended to dislike the other—and those high in a trait called “harm avoidance,” (basically, a sense of caution and worry) typically preferred the norepinephrine-affecting drug and disliked the serotonin drug.


Other studies have found possible links between particular genes and particular responses:
A gene associated with men’s ability to control anger was found to triple the risk that men would develop suicidal thoughts if given the drug citalopram (Celexa). The long version of a serotonin gene associated with the risk of developing depression following early life trauma was associated with a better or faster response to Prozac-like drugs, compared to the shorter version of that gene.Another serotonin-related gene was found to affect whether or not people experienced negative sexual side effects from one of these medications. Variations in genes for one of the brain’s opioid receptors have also been associated with positive responses to citalopram (Celexa).



Next: Part III