May 21, 2012 -- Before receiving treatment for her lifelong fear of spiders, one Chicago college student would flee her dorm for days if she merely suspected one's presence. She worried that her phobia would keep her from living on her own after graduation.
Another woman did not travel because she was terrified of spiders, even though she had long dreamed of going to Europe.
But after a single, two-hour therapy session in which they confronted their fear in the form of a tarantula named Florence, both women showed remarkable improvement in their actions -- and in their brains -- according to a new imaging study.
The therapy was so successful that people who previously could not be in the same room with the tarantula were able to touch and even hold the spider immediately after the session -- and they still showed little fear of Florence when reunited with her six months later.
About 1 in 10 Americans have phobias -- excessive fears of an object or situation that can have a profound impact on life.
Arachnophobia, or the fear of spiders, is among the most common, along with fear of snakes (ophidiophobia), heights (acrophobia), needles (trypanophobia), flying (pteromerhanophobia), and enclosed spaces (claustrophobia).
Exposure therapy, which involves planned confrontation with the feared object, is among the most successful treatments for phobias and other anxiety disorders, such as social anxiety disorder and obsessive-compulsive disorder (OCD).
The treatment is thought to train the brain to stop sending unwelcome "fight or flight" fear signals, and a new brain imaging study from Chicago's Northwestern University Feinberg School of Medicine suggests that this is exactly what happens.