Instead, paroxetine is more commonly prescribed for anxiety disorders, which is why researchers may have noted the personality changes. "Paroxetine wouldn't be anybody's number one choice for depression," Carroll said. "But it just might make sense that improving certain personality dimensions helps the patient's resilience against future relapse."
Deciding whether to take an SSRI or not has to be weighed against possible side effects, Carroll said, citing a recent study in the British Journal of Psychiatry that found that many people taking SSRIs reported feeling that the medications had blunted their emotions, both negative and positive ones. Other side effects may include headache, changes in sleep patterns, gastrointestinal upset and changes in sexual functioning, according to background information in that study.
"This business about the drugs affecting personality is not all necessarily good," Carroll said.
In another study from the December issue of Archives of General Psychiatry, patients with bipolar disorder who were taking antiepileptic drugs did not have an increased risk of suicide.
Anti-seizure drugs -- including gabapentin, pregabalin, topiramate and carbamazepine -- are not only used to treat epilepsy, but nerve disorder and bipolar disorder, according to background information in study.
Last year, the FDA warned of increased risk of suicidal thoughts and behavior related to the use of anti-seizure drugs but voted not to require a black box warning label about suicide risk.
Researchers from the University of Illinois at Chicago analyzed data on 47,918 patients with bipolar disorder, of which 13,385 patients received one of 11 anti-seizure drugs, while others received lithium or no treatment.
The rates of suicide among those taking anti-seizure drugs were no higher than for those taking lithium or those who received no treatment. And for patients taking anti-seizure drugs, suicide rates were five times higher before starting treatment than afterward.
The researchers said those with more severe illness may be more likely to be prescribed anti-seizure drugs or lithium.
The U.S. National Institute of Mental Health has more on depression.
SOURCES: Tony Tang, Ph.D., adjunct professor, department of psychology, Northwestern University, Evanston, Ill.; Bernard Carroll, M.D., scientific director, Pacific Behavioral Research Foundation, Carmel, Calif.; December 2009, Archives of General Psychiatry