December 7, 2009 By Megan Fellman
Now a new study led by a Northwestern University psychologist shows for the first time that an antidepressant medication can change patient personality substantially. Those personality changes are also linked to significantly better long-term improvements in mood. The findings will be published in the December issue of Archives of General Psychiatry, one of the JAMA/Archives journals. “Our findings lead us to propose a new model of antidepressant mechanism,” said Tony Z. Tang, adjunct professor of psychology in the Weinberg College of Arts and Sciences at Northwestern. “Our data suggests that modern antidepressants work partly by correcting key personality risk factors of depression.” Tang and colleagues studied the effects of the SSRI paroxetine (Paxil and Seroxat) in a placebo-controlled trial involving 240 adults with major depressive disorder. As typical in such clinical trials, patients taking paroxetine experienced moderately greater depression improvement than those receiving placebo. However, individuals taking paroxetine experienced a far greater decrease in neuroticism and an increase in extraversion than those receiving placebo.