Cognition & mood
Mild cognitive impairment, Parkinson's disease dementia, depression, anxiety, apathy, hallucinations and impulse-control disorders.
In this category
State of the art
No update yet for Cognition & mood. An update is a standalone state-of-the-art for the topic — what someone with Parkinson's needs to know about where this approach stands today.
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Longitudinal changes in national incidence of Parkinson’s disease and dementia in Korea: insights from the national health insurance database, 2003–2023 Dementia & MCI
A 20-year nationwide Korean insurance database study found new dementia diagnoses rose sharply from ~42 to ~172 per 100,000 person-years between 2003 and 2012, then declined after 2018 to ~113 by 2023, but trended significantly upward overall (AAPC +5.2%). Dementia disproportionately affected women, rural residents, and low-income recipients, who also had the shortest disease-free survival. -
Association of pulse pressure with incidence of dementia independent of established risk factors Dementia & MCI
In a UK Biobank prospective cohort of ~470,000 adults (9,028 dementia cases, median 13-year follow-up), each 10 mmHg rise in pulse pressure was associated with a 5.4% higher dementia hazard after full covariate adjustment. Importantly, no significant association was found for dementia with Lewy bodies — the subtype most closely linked to Parkinson's disease — suggesting the arterial-stiffness pathway to dementia may be less relevant for PD-type cognitive decline than for Alzheimer's disease. This is an unreviewed preprint. -
Co‐ and Multi‐Pathologies in Parkinson's Disease: An International Parkinson and Movement Disorder Society Scientific Issues Committee Review Dementia & MCI
The review documents that Alzheimer-type co-pathology (tau tangles and amyloid plaques) is among the strongest independent predictors of dementia in PD, above and beyond Lewy body burden itself; patients with higher Alzheimer co-pathology develop cognitive impairment faster and more severely, which this review frames as one of the most clinically important implications of the co-pathology picture. -
Cerebellar Network Compensation in Parkinsons Disease: Functional Connectivity Across Motor and Cognitive Circuits Dementia & MCI
Among 172 PD patients, those with normal cognition (MoCA ≥ 26) showed significantly stronger Crus I–left precentral gyrus connectivity than those with cognitive dysfunction, even after controlling for disease duration (cluster size 571 voxels, peak p-FEW = .018). This suggests that cerebellar-cortical coupling may be a functional correlate of cognitive preservation in PD, and its erosion may signal the transition toward MCI or dementia. -
A Comparative Evaluation of Structural MRI Foundation Models for Brain Age Regression and Sex Classification Dementia & MCI
Brain age derived from structural MRI — the target of the AI models tested here — is increasingly investigated as a predictor of cognitive decline in Parkinson's. This study's finding that foundation model performance is inconsistent across datasets adds a note of caution for researchers hoping to use such tools as progression or dementia-risk markers. -
Parkinson’s disease: tai chi may help manage symptoms – new research Dementia & MCI
Cognitive decline was measurably slower in the tai chi group than in controls across 3.5 years, adding long-term observational evidence that regular mind-body exercise may help protect against PD-related cognitive deterioration — though a randomised trial is needed to confirm this. -
Café pode ajudar cognição em pacientes com Parkinson; entenda - diariodopara.com.br Dementia & MCI
This 149-patient observational study highlights that executive-function deficits — planning, attention, impulse control — appear early in Parkinson's and are detectable with standardised neuropsychological batteries. Regular coffee consumption was associated with better scores on these early cognitive markers, though causation has not been established. -
Démence à corps de Lewy : voici pourquoi elle est confondue avec Parkinson et Alzheimer (et ce que ça change) - Cap Retraite Dementia & MCI
This explainer highlights that Lewy body dementia (LBD) is misdiagnosed in up to 67% of cases because it mimics both Parkinson's dementia and Alzheimer's, and explains the clinical features that distinguish the three — particularly the earlier appearance of hallucinations and fluctuating cognition in LBD versus the later memory loss seen in Parkinson's dementia. The article underscores that misdiagnosis has direct treatment consequences, as drugs appropriate for one condition can be harmful in another. -
Loneliness predicts worse Parkinsonism: a longitudinal, community-based, clinical-pathological study Depression
The study explicitly disentangles loneliness from depression: the predictive effect of loneliness on worse parkinsonism and faster motor decline remained statistically significant after controlling for depression. This is a clinically important distinction — it means screening and addressing loneliness in PD patients may matter separately from, and in addition to, treating depression. -
Multi-locus genetic dosage shapes cognitive disease progression in Parkinson’s patients: 15-year meta-analysis of 24 cohorts Dementia & MCI
This 15-year meta-analysis of nearly 7,800 PD patients across 24 cohorts shows that carrying more of five specific genetic risk variants steeply multiplies the chance of progressing to dementia: one variant raises risk 1.56-fold, two variants 3.21-fold, and three or more a striking 7.49-fold. The finding establishes a robust, dose-dependent genetic signal for cognitive decline in PD and points toward genetic stratification as a tool for identifying who needs the closest cognitive monitoring. -
Research to get excited about? Dementia & MCI
Two large observational studies (one using 7.23 million US insurance records, one using records of 269,725 UK men) found that PDE5 inhibitor use was associated with a meaningful reduction in Alzheimer's risk. A phase 2 RCT of the PDE5 inhibitor AR1001 (210 participants, 26 weeks) found it safe in mild-to-moderate Alzheimer's but did not meet its primary cognitive endpoints; a phase 3 trial (Polaris-AD, n=1,535) is ongoing with results expected in late 2026. -
Parkinson's Disease.
Depression, anxiety, apathy, and cognitive decline are described as intrinsic features of the disease rather than purely secondary reactions, arising from neurodegeneration beyond the dopamine system. The review notes these are often undertreated and calls for systematic screening at diagnosis and throughout follow-up.