This doesn't come as any big surprise, but Pfizerannounced this morning that it is putting a warning--and that's the company's word--on the label of its stop-smoking pill Chantix. It says people taking the drug should be watched for "serious neuropsychiatric symptoms, including changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior."

But PFE is quick to point out that, "A causal relationship between CHANTIX and these reported symptoms has not been established. In some reports, however, an association could not be excluded." You can read the full press release here.