BAKERSFIELD, Calif. -- Antidepressants have powers beyond lifting mood. They're also given to combat migraines and menopause symptoms.

But could they also alter personality traits? Doctors at Northwestern University put that question to the test.

They studied 240 patients with depression who were randomly assigned to take the antidepressant Paxil or a placebo for one year, or to undergo talk therapy sessions.

Results showed that people taking the antidepressants became more outgoing and had greater reductions of emotional instability than those taking a placebo or receiving cognitive therapy.

The improvements in emotional instability -- also called neuroticism -- were particularly interesting to the researchers.

People who are neurotic react badly to minor frustrations and are more likely to feel negative emotions such as stress, guilt, or anxiety.

Researchers found those who reduced their neuroticism were less likely to have a relapse in depression and may also be less vulnerable to other mental problems such as anxiety or eating disorders.