Smith, G.J.W.

Abstract INTRODUCTION Multicomponent non‐pharmacological interventions, such as the HABIT Healthy Action to Benefit Independence & Thinking® program, have shown promise for improving emotional well‐being, functioning, and self‐efficacy in both people with mild cognitive impairment (pwMCI) and their care partners. However, limited research has examined whether outcomes differ based on type of care partner who co‐enrolls with the pwMCI. METHODS We analyzed data from 875 pwMCI−care partner dyads who completed the HABIT program. Multivariate linear mixed‐effects regression models evaluated changes from baseline in outcomes by care partner type (spouse vs. non‐spouse) at post‐intervention, 6‐months, and 12‐ months. RESULTS At post‐intervention, pwMCI with spousal care partners demonstrated significant improvements across all outcomes from baseline, whereas those with non‐spousal partners improved in five out of seven outcomes. Across subsequent follow‐ups, pwMCI with spousal care partners showed sustained mean reductions in anxiety (post‐intervention: −2.0; 12‐month: −0.9) and increased compliance (post‐intervention: 5.7; 12‐month: 0.9). Everyday functioning in memory (post‐intervention: −0.9; 12‐months: 1.8) and executive functioning (post‐intervention: −0.7; 12‐months: 4.8) improved at post‐intervention but declined thereafter. Spousal care partners reported reduced anxiety (−1.2) and depression (−1.3) at post‐intervention, but by 12‐months they experienced increased burden, anxiety, and depression relative to baseline. Non‐spousal pwMCI–care partner dyads did not show significant change at 6 or 12‐months. DISCUSSION The HABIT intervention may have more favorable outcomes for pwMCI and care partners in spousal compared to non‐spousal dyads. These findings highlight the potential impact of care partner characteristics on both immediate and long‐term response to behavioral interventions for MCI. Highlights At post‐intervention, people with mild cognitive impairment (pwMCI) with spousal care partners showed significant improvements across all outcomes, while those with non‐spousal partners improved in five of seven outcomes. Gains attenuated over time for both spousal and non‐spousal dyads Spousal care partners reported reduced anxiety and depression at post‐intervention, but by 12 months they experienced increased burden, anxiety, and depression relative to baseline. Non‐spousal pwMCI–care partner dyads did not show significant change at 6 or 12 months.

Abstract Background Research on gender and ethnic differences in white matter tracts yields mixed results. Although men show larger global corpus callosum (CC) in absolute values, women have demonstrated larger splenium and isthmus. Additionally, men have shown greater white matter and fractional anisotropy (FA) in multiple regions than women. This study investigates sex and ethnic differences in the corpus callosum and transcallosal white matter tissue microstructure of older individuals with normal cognition and memory disorders. Method 191 participants (Female n = 120; Hispanics n = 115; Non‐Hispanics n = 76; Age mean = 71.07; SD = 7.75) were included in the sample from the 1Florida ADRC with cognitively normal ( n = 75), MCI ( n = 88), and dementia ( n = 28) diagnoses. Corpus callosum volumes were collected using a Siemens Skyra 3T MRI scanner and were divided into anterior, mid‐anterior, central, mid‐posterior, and posterior regions. Also, MRI‐based free water diffusion tensor imaging (FW‐DTI) measured FW‐corrected FA (fwcFA) to assess and compare the integrity of transcallosal tract templates (TCATT) across motor, temporal, parietal, and occipital regions across males and females and ethnic groups. Result Univariate ANCOVAs controlling for age and clinical diagnosis were performed; females had larger normalized CC volumes in the posterior, F (1, 184) = 8.92, p = .003, η p 2 = .046, mid‐anterior, F (1,184)= 5.68, p = .018, η p 2 = .030, and anterior, F (1,184)= 14.54, p < .001, η p 2 = .073, regions, which all survived FDR corrections, with no ethnic differences observed. For transcallosal tracts, females had higher fwcFA in the inferior temporal gyrus, η p 2 Hispanics had higher fwcFA in the premotor cortex, η p 2 η p 2 Conclusion Sex and ethnicity influence white matter changes during aging independently of age and cognitive diagnosis. However, the effect explained by these demographic variables was very small, suggesting the influence of additional factors.