Treatment with psychotropic medications may influence dementia risk in veterans with posttraumatic stress disorder (PTSD), according to data published in the Journal of the American Geriatrics Society.
There is emerging evidence for a relationship between dementia and a history of PTSD. Despite the common use of psychotropic medications for the treatment of PTSD in US veterans, there is little research into the effect of these medication classes on dementia outcomes.
Francis Mawanda, MBChB, PhD, from the University of Iowa in Iowa City, and colleagues sought to examine the effect of psychotropic medications on the association between PTSD and dementia in US veterans.
The investigators conducted a retrospective cohort study using data from a nationwide sample of US veterans ≥56 years of age in 2003. Data were excluded for veterans with a diagnosis of dementia or mild cognitive impairment at baseline. The investigators assessed for PTSD at baseline, psychotropic medication use, and a dementia diagnosis during a 9-year follow-up.
The cohort included 417,172 veterans (average age, 67.7 years; mean follow-up, 9.03 years). A diagnosis of PTSD was identified in 5.4% (n=22,674) of the veterans at baseline. Those with a PTSD diagnosis were more likely to be younger and have a diagnosis associated with a risk for dementia, such as diabetes mellitus, depression, substance abuse, and traumatic brain injury. After the 9-year follow-up, 6.15% (n=25,639) of the veterans in the study were diagnosed with dementia.
Before adjustment, a PTSD diagnosis was significantly associated with an increased risk for dementia diagnosis (hazard ratio [HR], 2.0; 95% CI, 1.89-2.11; P <.001). The risk continued to be elevated after adjusting for demographics (HR, 1.75; P <.001) and medical comorbidities (HR, 1.74; P <.001). The increased risk for dementia was sustained when demographics, medical comorbidities, psychiatric comorbidities, and healthcare use were taken into account (HR, 1.36; 95% CI, 1.28-1.44; P <.001).
Further, there were significant interactions between treatment of PTSD with selective serotonin reuptake inhibitors (P <.001), antipsychotics (P <.001), and newer antidepressants (P =.014) and the risk for dementia diagnosis after follow-up. The hazard ratios for dementia diagnosis after treatment with a psychotropic medication ranged from “1.99 for SSRI to 4.21 for [atypical antipsychotics],” according to the investigators.
After further adjustment, a PTSD diagnosis was associated with an increased risk for dementia diagnosis in veterans not receiving any psychotropic medication (HR, 1.55). However, the risk for dementia diagnosis increased with the addition of SSRI treatment compared with veterans with and without a PTSD diagnosis (HR 1.28 and HR 1.99, respectively).
“We found PTSD diagnosis was associated with a significantly increased risk for dementia diagnosis among veterans aged 56 years and older following comprehensive adjustment potential confounders,” the investigators wrote.
They noted that the results suggest “that the associations between PTSD diagnosis and the risk of dementia diagnosis varies significantly according to receipt of these medication classes.”
Mawanda F, Wallace RB, Mccoy K, Abrams TE. PTSD, psychotropic medication use, and the risk of dementia among US veterans: a retrospective cohort study. J Am Geriatr Soc. 2017;65(5):1043-1050. doi: 10.1111/jgs.14756