After watching "Thirteen" I wanted to learn more about destructive behaviors that seems to serve as a form of relief for many teen girls (despite how gruesome they appear to outsiders). As I was researching cutting behavior in teen girls--which turns out to be extremely prevalent--I found this study on a possible (and probable) neuro-bio connection. Pretty cool findings. I pasted the link to the whole article below but I think you'll get the idea from the few paragraphs I included. enjoy!
http://www.sciencedaily.com/releases/2006/06/060616135015.htm
University of Washington psychologists have discovered that adolescent girls who engage in behaviors such as cutting themselves have lower levels of serotonin, a hormone and brain chemical, in their blood. They also have reduced levels in the parasympathetic nervous system of what is called respiratory sinus arrhythmia, a measure of the ebb and flow of heart rate along with breathing.
"A low level of this measure of the parasympathetic nervous system is characteristic of people who are anxious and depressed and among boys who are delinquent. But this is the first study to show it among adolescent girls who engage in self-harming behavior," said Theodore Beauchaine, UW associate professor of psychology.
To find physiological markers of self-harming behavior, the UW researchers showed both groups of adolescents a three-minute film clip from the movie "The Champ" depicting a boy with his dying father. Previous studies have shown the film can induce sadness. A number of different psychophysiological measures were collected from each of the girls before, while and after viewing the film clip. Following the viewing a small blood sample was taken to measure whole-blood serotonin.
The girls who engaged in self-harming behavior had lower levels of respiratory sinus arrhythmia in their parasympathetic nervous system while watching the film clip. These measures, the researchers argue, support the idea that the inability to regulate emotions and impulsivity can trigger self-harming behavior.
This is interesting research--you wouldn't expect to find lower-than-average respitory sinus arrhythmia and reactivity in people who are anxious. I would expect heart-rate to be especially labile in the anxiety-prone. In fact, you usually see low reactivity and autonomic arousal from psychopaths, who are the ultimate cool customers. Or maybe I'm twisted and it DOES make sense, because the parasympathetic NS is meant to inhibit and reign in arousal... someone straighten me out.
ReplyDeleteThe low serotonin makes sense, though. I know serotonin has been found to have an effect on anxiety by calming obsessive (over-)thinking, and it might almost be tautological to say that anxious girls have lowered serotonin production.