Scientific American: Depression Drugs Affect Personality

Scientific American follows up on the study that showed that antidepressant drugs affect personality.

Experts have long known that the placebo effect explains much of the mood lift patients report after going on antidepressants. This was the case in the new study, published in the journal Archives of General Psychiatry—patients with major depressive disorder who were given a placebo saw their symptoms improve about three quarters as much as those given paroxetine, an antidepressant also known as Paxil. But only the patients who took paroxetine displayed personality changes in two key areas of the widely used five-factor model of personality: they scored lower on neuroticism, the tendency to experience negative emotions such as guilt and anxiety, and they scored higher on extroversion, which includes traits such as talkativeness and assertiveness.

Personality traits are thought to be relatively stable over a person’s life—even the onset of depression, which comes with unusually low moods, should not alter a person’s fundamental traits. Personality can affect a person’s risk for mental illness, however—past research has established neuroticism as a key risk factor for depression, explains Tony Tang of Northwestern University, the lead author of the study. Tang and his colleagues found that the more a patient’s neuroticism dropped while taking paroxetine, the smaller the chance that his or her depression would return after they stopped taking the drug.

The study “proves in an elegant way that antidepressant medications and placebo have different actions in many cases,” says Andrew Leuchter, a depression researcher at the University of California, Los Angeles, who was not a part of the study. “This may explain in part some of the ways that antidepressants have a therapeutic benefit for some patients.”

Yeah, "therapeutic benefits": start an affair, compulsively lie about it, ditch your marriage, have promiscuous sex. Much more beneficial... or just manic if you ask me. Did they ever stop to ask what you would get if you took someone who already pegged the extroversion meter a drug that would further increase extroversion? My answer: mania.