Still, Resnick said that her study might ultimately affect younger women following the therapy.
"This suggests that a lot more research is needed in that younger age range," she said.
While praising the study as a whole, others were a bit more skeptical about the affects on women following the treatment.
"It's hard to extend these to the younger subjects, because they might have a whole different subset of risk factors for stroke," said Dr. James Brewer, a neurologist at the University of California at San Diego.
He said that the study does reinforce suspicions that hormone therapy could lead to mental decline.
"I think that this gives biological support to the findings about the effects of hormone therapy on cognition," Brewer said.
He noted that most women probably don't need to be concerned, even if the findings hold up, because the negative effects were limited and affected a smaller subset of women. But he said the number of people involved in the study leads him to believe those effects are very real.
"They're small effects, but I think the repeatability across studies was convincing to me in such a large group of subjects," he said.
While the research may open new avenues of study for the safety of hormone replacement therapy, Resnick is not prepared to make any new recommendations now based on her findings.
"It does give people a broader perspective in terms of trying to make decisions about hormone therapy," she said, adding, "This suggests that a lot more research is needed in that younger age range."
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