Cognitive ability, evaluated by the Paced Auditory Serial Addition Test (PASAT), also improved in those treated with estriol. In the authors' abstract, they indicated that this result warranted further experimentation through a placebo-controlled clinical trial.[8] This experiment was small, with only six women with relapse remitting MS (RRMS) and four women with secondary progressive MS (SPMS) finishing the trial. The authors noted that estriol generally improved symptoms in women with RRMS, but not in those with SPMS.[9]