Antidepressants Change Personality, Study Suggests

MONDAY, December 7 (Health.com) — People who take antidepressants such as Paxil often say they feel less stressed and more outgoing, lively, and confident. Now a new study suggests it's not just because they're less depressed.

In fact, such drugs may alter two key personality traits linked to depression—neuroticism and extraversion—independently of their effect on depression symptoms.

"Medication can definitely change people's personalities, and change them quite substantially," says the lead author of the study, Tony Z. Tang, PhD, a professor of psychology at Northwestern University in Evanston, Ill. The findings show that "those changes are very important," he says.

In the study, people who took Paxil (paroxetine), a selective serotonin-reuptake inhibitor (SSRI), had a drop in neuroticism, which is a tendency toward emotional instability and negative mood. They also had an increase in extraversion, which is a tendency toward outgoingness and positive mood, compared to similarly depressed people taking placebo.

And the more drastic the personality shift, the less likely depressed patients were to relapse, according to the study, published this week in the Archives of General Psychiatry.

Although the study looked only at Paxil, other SSRIs (such as Prozac and Zoloft) are likely to have the same effect on personality, Tang says.

The notion that antidepressant drugs—and SSRIs in particular—can cause personality changes is not new. But many researchers have attributed these changes to a patient's improved mood, and have been skeptical that SSRIs had independent effects on personality.

The current research is a "confirmation of what I observed a number of years ago," says psychiatrist Peter D. Kramer, MD, the author of the landmark 1993 book Listening to Prozac, which described how patients treated with antidepressants often became more at ease socially and less sensitive to rejection.

"It looks like a lot of what gives people relief is that they're feeling whatever the opposite of neuroticism is," says Dr. Kramer, a clinical professor of psychology and human behavior at Brown University in Providence, R.I. "Getting better very solidly seems to predict a longer period before the next episode. That argues against the notion that these medications are just band-aids [that] get people through."