Dementia is a major public health problem worldwide. Emerging research indicates that clinical infections and PTSD could be important risk factors for dementia. However, evidence for infections and the risk of dementia primarily examines central nervous system (CNS) infections. Extant epidemiological evidence for systemic bacterial infections and the risk for dementia is limited while that for PTSD and the risk for dementia did not account for psychotropic medications commonly used in management of PTSD and could affect cognitive function. The purpose of this study was to 1) review the evidence for CNS infections as possible causes of Alzheimer’s disease (AD) dementia, and 2) using nationwide Veterans Health Administration databases, conduct original retrospective cohort analyses in nationally representative samples of U.S. veterans aged 56 years and older to determine the associations between systemic bacterial infections, PTSD, and psychotropic PTSD medication use with the risk for developing dementia. Review of the research pertaining to an infectious AD etiology hypothesis including the various mechanisms through which different clinical and subclinical infections could cause or promote the progression of AD, and the concordance between putative infectious agents and the epidemiology of AD showed evidence linking AD to an infectious cause to be largely inconclusive; however, the amount of evidence suggestive of an association is too substantial to ignore. Analysis of the associations between systemic bacterial infections and the risk for dementia showed a significant association between exposure to any systemic bacterial infection and an increased risk for dementia (hazard ratio [HR] = 1.20; 95% confidence interval [CI] = 1.16-1.24) after adjustment for demographic characteristics, and medical and psychiatric comorbidity. In addition, septicemia (HR=1.39; 95%CI=1.16-1.66), bacteremia (HR=1.22; 95%CI=1.0-1.49), osteomyelitis (HR=1.20; 95%CI=1.06-1.37), pneumonia (HR=1.10; 95%CI=1.02-1.19), UTI (HR=1.13; 95%CI=1.08-1.18), and cellulitis (HR=1.14; 95%CI=1.09-1.20) were independently associated with significantly increased risk of developing dementia after adjustment for potential confounders. Analysis of the associations between PTSD and psychotropic PTSD medication use with the risk for dementia showed a significant association between PTSD and the risk for dementia (HR=1.35; 95%CI=1.27-1.43) after adjustment for demographic characteristics, medical and psychiatric comorbidity, and health care utilization. Analysis of the impact of psychotropic PTSD medications including selective serotonin reuptake inhibitors (SSRI), serotonin-norepinephrine reuptake inhibitors (SNRI), benzodiazepines (BZA), novel antidepressants (NA) and atypical antipsychotics (AA) on the association between PTSD and the risk for dementia showed significant interactions between PTSD and use of SSRIs (p<.0001), NAs (p=.0016), and AAs (p<.0001). Multivariate analysis showed a significant association between PTSD and an increased risk for dementia among individuals not using any psychotropic PTSD medications at baseline (HR=1.70; 95%CI=1.58-1.82). PTSD patients using SSRIs (HR=2.10; 95%CI=1.82-2.41), NAs (2.19; 95%CI=1.94-2.48) or AAs (4.56; 95%CI=4.04-5.15) were significantly more likely to develop dementia compared to those without PTSD and not using any psychotropic PTSD medications. PTSD patients using SSRIs (HR=1.24; 95%CI=1.08-1.42), NAs (HR=1.29; 95% CI=1.14-1.46) or AAs (HR=2.69; 95%CI=2.38-3.04) were also significantly more likely to develop dementia compared to those with PTSD and not using any psychotropic PTSD medications. SNRI (HR=1.35; 95%CI=1.26-1.46) and BZA drug use (HR=1.40; 95%CI=1.35-1.45) at baseline was associated with an increased risk for dementia regardless of PTSD diagnosis. These findings indicate; 1) evidence for an infectious AD etiology hypothesis in inconclusive, 2) both severe (e.g. sepsis), and less severe (e.g. cellulitis) systemic bacterial infections are collectively and independently associated with an increased risk of dementia among older U.S. veterans hence prevention of systemic bacterial infections could positively influence the risk for dementia among older adults, and 3) PTSD and psychotropic medication use are associated with an increased risk for dementia among U.S. veterans. Further epidemiologic, clinical, and basic science research is required to elucidate the mechanisms and the associations between infections and the risk for dementia and to determine if the independent and effect modifying impacts of psychotropic PTSD medication use on the risk for dementia are related to differences in PTSD severity, other psychiatric comorbidity, or whether psychotropic PTSD medication use is an independent risk factor for dementia.

Background: Postnatal PTSD affects between 1 and 6% of women, whereas 30% are partially symptomatic. The mental health of new mothers is of public health concern as it could affect the marital relationship and the behavioural and emotional health of children. Little research has explored emotional regulation difficulties as predictors for postnatal PTSD. Treatments such as Cognitive Behavioural Therapy (CBT) have long waiting list times and may be hard to access for new mothers. Aim: The relationship between key predictors especially those associated with emotional regulation and PTSD in postnatal women was investigated. The feasibility of using internet based writing therapy for women with postnatal PTSD was assessed. Exploration of women's views about writing therapy as a therapeutic tool and their lived experience of PTSD was undertaken. Methods: Two literature reviews were conducted; firstly to identify the types of therapy previously used for women with postnatal PTSD, secondly to identify necessary conditions for effective writing therapy. The quantitative phase used measures for key predictors of PTSD and incorporated a feasibility study for a writing intervention. Regression analysis for a variety of predictors and PTSD and general and psychological health was conducted on data from 211 women. In the qualitative phase narrative analysis was used on interview transcripts from seven non-writers exploring access to writing and their experience of PTSD. An in depth case study was conducted on a woman who participated in the intervention and who was interviewed. Findings: The quantitative phase showed that planning the pregnancy; whether the baby slept or fed as expected; maternal confidence; past trauma; attachment patterns; self-efficacy; social support and partner support correlated with PTSD. However, the pain component of the birth experience mediated the effect of affects and alexithymia on general and psychological health. Most women did not access writing therapy. The qualitative phase showed that complicating factors and relationships with staff and mothers affect women's experience of PTSD and their view of themselves. Social media was used by women for support. Conclusion: Emotion regulation difficulties could impact postnatal mental health. Antenatal screening for alexithymia may be useful. Women value good relationships with staff during labour. The role of social media for postnatal mental health support should be investigated.