Nancy A. Melville

April 10, 2017

UPDATED April 11, 2017 // SAN FRANCISCO – Posttraumatic stress disorder (PTSD) in middle-aged women is linked with significant cognitive impairment, with the effect stronger in those with comorbid depression, new research shows.

"We found that women with probable PTSD and depression showed strong associations with worse cognitive function compared to women with either no trauma or no depression," said first author Jennifer A. Sumner, PhD, of Columbia University Medical Center, New York City.

The findings were presented here at the Anxiety and Depression Association of America (ADAA) Conference 2017.

PTSD Research in Women Hampered

Previous evidence has shown that PTSD is twice as common in women as men, yet most PTSD research focuses on male veterans or male patients recruited from healthcare clinics. The understanding of how the disorder is manifested in women has thus been hampered.

"We really need more work on this in civilians, non-treatment-seeking individuals, and particularly women," Dr Sumner said.

To help address the need, the investigators evaluated data on 14,029 women from the Nurses' Health Study II. The study included US nurses recruited in 1989 who were aged 25 to 42 years at baseline; 95% were white.

The participants' lifetime trauma exposure and PTSD symptoms were assessed in 2008. Cognitive function was assessed in 2014-2016. At the time of cognitive assessment, the average age of the women was 49 to 69 years.

Women who had not been exposed to trauma were compared to women with probable PTSD symptoms. After fully adjusting for age, sociodemographic factors, depression, and medical factors, women with probable PTSD symptoms performed significantly worse with respect to psychomotor speed and attention (P = .04), learning and working memory (P < .02), and overall cognition (P < .0001).

More severe PTSD, defined as having four to seven symptoms, corresponded with greater deficits in learning and working memory, Dr Sumner noted.

Sizeable Effect

"We found that the mean difference for the highest level of PTSD symptoms was equivalent to that of nearly 4 years of aging, so it was a sizable effect that we're observing," she said.

The effect was somewhat attenuated in full-adjustment models (P = .02) but was still significant.

In addition, each year of increasing age was associated with significantly worse cognitive performance.

The strongest associations were among women with depression in addition to PTSD. For these women, there was significant impairment in psychomotor speed and attention (P =.001) and learning and working memory (P < .001) compared to women who did not have PTSD or depression.

"We found the strongest associations were observed along women with elevated PTSD and depressive symptoms, and this may suggest that the comorbidity phenotype of concurrent PTSD and depression may be particularly associated with worse cognitive function," Dr Sumner said.

She noted, however, the possibility that the women with depression may have had more severe PTSD. That could explain worse cognitive function, a fact that underscores the need for further research.

A wide range of underlying health factors associated with PTSD could also play a role in the cognitive decline, including obesity, physical inactivity, and sleep disturbances, Dr Sumner added.

She further cited recent research that has linked PTSD with increased oxidative stress, which can accelerate cellular aging. Other research has reported associations with the neuroendocrine system and an inflammatory response, Dr Sumner noted.

"Going forward, it's very important that research distinguish between preexisting and acquired brain deficits, which are critical for understanding mechanisms as well as interventions," she said.

Foundation for Future Research

Another important question is whether treatment of PTSD and/or depression could be associated with improvements in cognitive function, Dr Sumner told Medscape Medical News.

She noted a small pilot study in which veterans with PTSD who participated in mindfulness-based stress reduction showed improvements after undergoing treatment.

Other research also suggests that antidepressant treatment for late-life depression may have some beneficial, albeit small, effects on cognition, Dr Sumner said.

"Together, these studies provide some promising initial data that can serve as a foundation for future work.

"If we can demonstrate that treatment of PTSD and/or depression improves cognitive function, then that will provide yet another reason for why it is important to have access to empirically supported treatments for these psychological conditions."

The implications could be far-reaching, Dr Sumner added.

"More than 50% of Americans with PTSD do not receive treatment, and it is critical to improve access to mental health care in the US."

Commenting on the findings for Medscape Medical News, Mark W. Miller, PhD, a clinical research psychologist with the National Center for PTSD at the VA Boston Healthcare System, said the findings are consistent with those seen in men and add importantly to the previous research.

"Much of what was previously known about the association between PTSD and poor cognitive functioning was based on research with older male veterans who are at elevated risk for a host of adverse health outcomes," he told Medscape Medical News.

"Until now, it was not clear if that association reflected something unique to the effects of war trauma in that population or if the link between PTSD and cognitive decline would also be found in the general population and/or samples of women with other types of trauma histories and health profiles," Dr Miller said.

"The findings of this study demonstrate the generalizability of the relationship between PTSD and mild cognitive impairment to women and civilians."

He noted that an important question in considering the potential treatment effects on cognition is knowing when the cognitive impairment first occurred.

"Because cognitive performance was assessed at only one time point in this study, we still do not know if PTSD causes cognitive impairment or if cognitive impairment confers risk for PTSD or both," Dr Miller explained.

"If the impairment predated the PTSD, it's not obvious to me that PTSD treatment would help.

"On the other hand, if the impairment is a reflection of current PTSD symptoms or a consequence of PTSD — and most of the literature is pointing in that direction ― then one would certainly expect that PTSD treatment could reverse those effects."

The authors and Dr Miller have disclosed no relevant financial relationships.

Anxiety and Depression Association of America (ADAA) Conference 2017. Abstract 340R, presented April 7, 2017.


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