MentalHealthDaily

Blood microRNAs Linked to Hippocampal Atrophy in Rhineland Study

by GLOOM

MHD featured image for blood microRNA signatures and hippocampal atrophy.

A 2026 Molecular Psychiatry analysis from the Rhineland Study found that blood-derived microRNA signatures were associated with hippocampal brain structure: 6 microRNAs linked cross-sectionally to left hippocampal volume, and 5 different microRNAs linked longitudinally to hippocampal atrophy rates.1 The result is biomarker-discovery evidence for brain aging, not a ready dementia blood test. Research Highlights Baseline …

Falling Dementia Rates Linked to Generational Memory Gains

by GLOOM

Photoreal illustration representing generational gains in memory across older adults, with imagery of overlapping age trajectories and hippocampal motifs.

Dementia rates in the US, UK, Netherlands, Sweden, France, and several other high-income countries have been falling for decades, despite population aging. The standard explanation — improved cardiovascular care, more education, and less smoking in later-born cohorts — is real but incomplete. Research Highlights Dementia incidence has been falling about 13% per decade in Western …

Adult Hippocampal Neurogenesis Added 670,000 Rat Dentate Neurons

by GLOOM

MHD featured image for adult hippocampal neurogenesis and dentate gyrus neuron turnover.

A 2026 rat study estimated that adult hippocampal neurogenesis added 670,000 dentate gyrus granule neurons from 2 to 18 months of age, but the total dentate gyrus population grew by only 385,000 cells because older developmentally born neurons were also being lost.1 The result makes adult neurogenesis look numerically larger than the usual “tiny trickle” …