Hall, G. | bioRxiv Science

bioRxiv2019

Brain Aging in Major Depressive Disorder: Results from the ENIGMA Major Depressive Disorder working group

BackgroundMajor depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in MDD patients, and whether this process is associated with clinical characteristics in a large multi-center international dataset. MethodsWe performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 29 samples worldwide. Normative brain aging was estimated by predicting chronological age (10-75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 1,147 male and 1,386 female controls from the ENIGMA MDD working group. The learned model parameters were applied to 1,089 male controls and 1,167 depressed males, and 1,326 female controls and 2,044 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted "brain age" and chronological age was calculated to indicate brain predicted age difference (brain-PAD). FindingsOn average, MDD patients showed a higher brain-PAD of +0.90 (SE 0.21) years (Cohens d=0.12, 95% CI 0.06-0.17) compared to controls. Relative to controls, first-episode and currently depressed patients showed higher brain-PAD (+1.2 [0.3] years), and the largest effect was observed in those with late-onset depression (+1.7 [0.7] years). In addition, higher brain-PAD was associated with higher self-reported depressive symptomatology (b=0.05, p=0.004). InterpretationThis highly powered collaborative effort showed subtle patterns of abnormal structural brain aging in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the predictive value of these brain-PAD estimates. FundingThis work was supported, in part, by NIH grants U54 EB020403 and R01 MH116147.

neuroscience↗

bioRxiv2019

Assessing the potential impact of Medicaid work requirements on African-Americans via a welfare reform analysis: A systematic review

The Centers for Medicare and Medicaid Services are currently approving Medicaid demonstration projects involving work and community engagement requirements. The fear among public health professionals and policymakers is that these work requirements will disproportionately limit access to health insurance for African-Americans. To investigate these new work requirements for Medicaid, we conducted a systematic review of the Temporary Assistance for Needy Families program, the last major welfare program to have such work requirements. We used the ProQuest database and selected scholarly journal studies in English and published between January 1991-August 2018. Our selection strategy yielded 14 eligible studies, eight of which focused on caseload movements and six focused on sanctions. We found that African-Americans entered TANF at a higher rate than Whites, remained on TANF longer, and were subject to sanctions more frequently and stringently than Whites were. These results suggest that African-Americans may disproportionately experience reduced access to care through sanctioning such as lockout periods. Recommended policy changes include prohibiting work activities as a condition of Medicaid coverage, strengthening Medicaid in other ways, combating discriminatory hiring practices, and easing burdensome reporting requirements.

scientific communication and education↗