Biomarkers.

Background: Psychotic symptoms may manifest in Alzheimer's disease (AD), especially in advanced disease stages and in patients with higher polygenic risk scores for schizophrenia (SCZ-PRS). Such genetic risk seems also to influence grey matter volume (GMV) alterations in patients with psychosis. Since multiple neurotransmitter systems, namely dopamine (DA) and serotonin (5-HT), have been implicated in psychosis, the aim of this study was to investigate whether a SCZ-PRS may explain variance in the association between GMV and the cerebral distribution of DA and 5-HT.

Biomarkers.

Background: Tau protein tangles have been recently shown to accumulate in multiple brainstem nuclei in pre-cortical Alzheimer's disease (AD) stages. The impact of neurotransmission alterations on brain atrophy and their genetic correlates in AD remain unexplored. Therefore, the aims of this study were: 1) to investigate associations between grey matter (GM) loss across the AD continuum and the distribution of multiple neurotransmitter receptors/transporters; 2) to investigate the impact of polygenic risk scores for AD (PRSs) on such associations.

Biomarkers.

Background: The impact of white matter hyperintensities (WMH) on cognitive performance is uncertain due to inconsistent findings. The thalamus is of particular interest given its susceptibility to vascular damage. To test how different vascular risks (Deep/Periventricular WMH and Vascular Scores (VS)) affect thalamic subregional volumes and whether that has any mediating effect on different cognitive domains in healthy controls, mild cognitive impairment (MCI) and AD.

Public Health.

Background: Sexual minority older adults (SMOAs) report subjective cognitive decline (SCD) more than heterosexual older adults (HOAs). Inconsistent findings have emerged about the risk of cognitive decline in SMOAs. This study aimed to compare the impact of multiple psycho-social risk factors on both objectively assessed and subjectively reported cognitive decline between HOAs and SMOAs.

Biomarkers.

Background: Sporadic Alzheimer's disease (AD) accounts for >90% of AD cases, of which 70% are thought to be due to a combination of several risk genes. Of these, Apolipoprotein E (APOE) is the most studied gene. Given that the APOE ɛ4 risk variant is found in ∼14% of the general population and ∼37% of the AD population, APOE ɛ4 is neither necessary nor sufficient to cause AD on its own.