Previous studies had raised questions about adverse behavioral changes with statins, such as irritability or violence, but findings with statins have been inconsistent. For postmenopausal women, said the scientists, the typical effect was increased aggression. The effect was significant for postmenopausal women older than age 45. The increase in aggression (compared to placebo) appeared stronger in women who began with lower aggression at baseline. For men, the picture was more complex. Three male participants who took statins (and no one on placebo) displayed very large increases in aggression. When these were included in analysis, there was no average effect. When these results were removed from the analysis, a decline in aggressive behavior for male statin users was significant. It was stronger among younger men who tend to be more aggressive, however, the effect was most evident in less aggressive men. — The findings were published July 1 in the online issue of PLOS ONE.