The natural history of depressive symptoms in patients with incident Parkinson’s disease: a prospective cohort study

Potential Impact of Hypoxic Astrocytes on the Aggravation of Depressive Symptoms in Parkinson's Disease

Mounting evidence suggests a significant correlation between depressive disorders and neurodegenerative conditions, encompassing Alzheimer's disease and Parkinson's disease (PD). Depression represents a substantial non-motor manifestation frequently identified in individuals with PD, posing a significant threat to patients' overall well-being and necessitating the implementation of effective management strategies. Despite its high prevalence, impacting over 40% of PD patients, the precise cellular and molecular mechanisms underlying depression and its relationship to dopaminergic system degeneration remain largely ambiguous. In this study, we presented our findings demonstrating distinct characteristics of cortical astrocytes in PD patients compared to reactivated glial cells in the substantia nigra. We identified a subset of differentially expressed genes associated with depressive disorders from PD-associated cortical astrocytes. Furthermore, we uncovered the potential involvement of the hypoxia signaling in driving cortical astrocytic dysfunctions. Through a comprehensive investigation utilizing transcriptome and chromatin accessibility analyses on cultured human astrocytes, we revealed that hypoxic treatment could induce similar expression changes observed in cortex from PD patients. Additionally, we provided evidence that activation of the HIF-1 signaling pathway suppressed the expression of key components of mitochondrial ribosomes and electron transport chain proteins COX2 and CYTB, resulting in abnormal mitochondrial membrane potential. Our results underscore the potential impact of glial metabolic abnormalities on the development of depressive disorders associated with Parkinson's disease.

Effect of Zishen pingchan granules combined with pramipexole on serum BDNF, IL-1β, IL-6, CRP, TNF-α levels in depressed patients with Parkinson's disease: Results of a randomized, double-blind, controlled study

INTRODUCTION

Depression is a common comorbidity in Parkinson's Disease (PD) and treatment of depression can significantly support PD management. Zishen pingchan granules (ZPG), a traditional Chinese herbal formula, may help ameliorate depressive symptoms in PD patients. However, the molecular mechanisms underlying the effects of ZPG remain unclear. This study aimed to investigate the impact of ZPG on serum levels of brain-derived neurotrophic factor (BDNF), interleukin-1β (IL-1β), interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-α (TNF-α) in PD patients with depression.

METHODS

Eighty PD patients treated with pramipexole but still experiencing mild to moderate depression symptoms were randomly allocated to a group receiving 12-week ZPG treatment (n = 40) or placebo (n = 40). The Hamilton Depression Scale 17 items (HAM-D-17) was utilized to evaluate changes in depressive symptoms from baseline over 12 weeks, while the Unified Parkinson's Disease Rating Scales (UPDRS) part 3 was employed to assess changes in motor symptoms over the same duration. Serum levels of BDNF, IL-1β, IL-6, CRP, and TNF-α were measured at baseline and post-treatment.

RESULTS

Seventy-one participants completed the study. Following treatment, both groups showed significantly reduced HAMD scores. The placebo group demonstrated a decrease in BDNF levels, while the ZPG group showed an increase in IL-6 levels post-treatment. In the examination of the group-time interaction, the ZPG group exhibited a greater decrease in HAMD scores and increase in IL-6 levels compared to the placebo group. Conversely, the placebo group showed a greater decrease in BDNF levels compared to the ZPG group. However, no significant group differences were observed in UPDRS part 3 change scores or serum levels of IL-1β, CRP, or TNF-α change from baseline.

CONCLUSION

ZPG may potentially ameliorate depressive symptoms in PD patients, with the potential mechanism involving mitigation of reductions in serum BDNF level and an increase in IL-6 level.

The pathobiological basis of depression in Parkinson disease: challenges and outlooks

Depression, with an estimated prevalence of about 40% is a most common neuropsychiatric disorder in Parkinson disease (PD), with a negative impact on quality of life, cognitive impairment and functional disability, yet the underlying neurobiology is poorly understood. Depression in PD (DPD), one of its most common non-motor symptoms, can precede the onset of motor symptoms but can occur at any stage of the disease. Although its diagnosis is based on standard criteria, due to overlap with other symptoms related to PD or to side effects of treatment, depression is frequently underdiagnosed and undertreated. DPD has been related to a variety of pathogenic mechanisms associated with the underlying neurodegenerative process, in particular dysfunction of neurotransmitter systems (dopaminergic, serotonergic and noradrenergic), as well as to disturbances of cortico-limbic, striato-thalamic-prefrontal, mediotemporal-limbic networks, with disruption in the topological organization of functional mood-related, motor and other essential brain network connections due to alterations in the blood-oxygen-level-dependent (BOLD) fluctuations in multiple brain areas. Other hypothetic mechanisms involve neuroinflammation, neuroimmune dysregulation, stress hormones, neurotrophic, toxic or metabolic factors. The pathophysiology and pathogenesis of DPD are multifactorial and complex, and its interactions with genetic factors, age-related changes, cognitive disposition and other co-morbidities awaits further elucidation.

Parkinson's Disease and Parkinsonism

Parkinson's disease is a progressive neurodegenerative disease characterized by tremor and bradykinesia and is a common neurologic ailment. Male sex and advancing age are independent risk factors and, as the population ages, is taking an increasing toll on productivity and medical resources. There are a number of other extrapyramidal conditions that can make the diagnosis challenging. Unlike other neurodegenerative diseases, idiopathic Parkinson's disease has effective treatments that mitigate symptoms. Medications can improve day-to-day function and, in cases where medication does not give a sustained benefit or has significant side effects, treatments like deep brain stimulation result in improved quality of life.

Genome-wide Burden of Rare Short Deletions Is Enriched in Major Depressive Disorder in Four Cohorts

BACKGROUND

Major depressive disorder (MDD) is moderately heritable, with a high prevalence and a presumed high heterogeneity. Copy number variants (CNVs) could contribute to the heritable component of risk, but the two previous genome-wide association studies of rare CNVs did not report significant findings.

METHODS

In this meta-analysis of four cohorts (5780 patients and 6626 control subjects), we analyzed the association of MDD to 1) genome-wide burden of rare deletions and duplications, partitioned by length (<100 kb or >100 kb) and other characteristics, and 2) individual rare exonic CNVs and CNV regions.

RESULTS

Patients with MDD carried significantly more short deletions than control subjects (p = .0059) but not long deletions or short or long duplications. The confidence interval for long deletions overlapped with that for short deletions, but long deletions were 70% less frequent genome-wide, reducing the power to detect increased burden. The increased burden of short deletions was primarily in intergenic regions. Short deletions in cases were also modestly enriched for high-confidence enhancer regions. No individual CNV achieved thresholds for suggestive or significant association after genome-wide correction. p values < .01 were observed for 15q11.2 duplications (TUBGCP5, CYFIP1, NIPA1, and NIPA2), deletions in or near PRKN or MSR1, and exonic duplications of ATG5.

CONCLUSIONS

The increased burden of short deletions in patients with MDD suggests that rare CNVs increase the risk of MDD by disrupting regulatory regions. Results for longer deletions were less clear, but no large effects were observed for long multigenic CNVs (as seen in schizophrenia and autism). Further studies with larger sample sizes are warranted.

Visuospatial functioning is associated with sleep disturbance and hallucinations in nondemented patients with Parkinson's disease

Introduction: Cognitive impairment is a common symptom of Parkinson's disease (PD) associated with reduced quality of life and a more severe disease state. Previous research has shown an association between visuospatial dysfunction and worse disease course; however, it is not clear whether this is separable from executive dysfunction and/or dementia. This study sought to determine whether distinct cognitive factors could be measured in a large PD cohort, and if those factors were differentially associated with other PD-related features, specifically to provide insight into visuospatial dysfunction. Methods: Non-demented participants with PD from the Pacific Udall Center were enrolled (n = 197). Co-participants (n = 104) completed questionnaires when available. Principal components factor analysis (PCFA) was utilized to group the neuropsychological test scores into independent factors by considering those with big factor loading (≥.40). Linear and logistic regression analyses were performed to examine the relationship between the cognitive factors identified in the PCFA and other clinical features of PD. Results: Six factors were extracted from the PCFA: 1) executive/processing speed, 2) visual learning & memory/visuospatial, 3) auditory working memory, 4) contextual verbal memory, 5) semantic learning & memory, and 6) visuospatial. Motor severity (p = 0.001), mood (p < 0.001), and performance on activities of daily living scores (informant: p < 0.001, patient: p = 0.009) were primarily associated with frontal and executive factors. General sleep disturbance (p < 0.006) and hallucinations (p = 0.002) were primarily associated with visuospatial functioning and visual learning/memory. Conclusions: Motor symptoms, mood, and performance on activities of daily living were primarily associated with frontal/executive factors. Sleep disturbance and hallucinations were associated with visuospatial functioning and visual learning/memory only, over and above executive functioning and regardless of cognitive disease severity. These findings support that visuospatial function in PD may indicate a more severe disease course, and that symptom management should be guided accordingly.

Caregiver Burden and Quality of Life in Early and Late Stages of Idiopathic Parkinson's Disease

OBJECTIVE

Idiopathic Parkinson's disease (IPD) is a chronic progressive neurodegenerative movement disorder characterized by motor and non-motor symptoms that affects patients' quality of life and caregiver burden. The aim of our study was to assess the caregiver burden (CB) in early and late stages of disease and to search if there was a relationship between quality of life and CB.

METHODS

A total of 74 patients who were diagnosed as having IPD by a movement disorder neurologist according to United Kingdom Brain Bank Criteria and their caregivers were randomly selected for participation the study. Staging of PD was performed by the neurologist based on the Hoehn and Yahr (H&Y) Scale. Disease severity was determined using the Unified Parkinson's Disease Rating Scale (UPDRS). CB was evaluated using the Zarit Caregiver Burden Inventory (ZCBI). The Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory (BDI) were used to assess anxiety and depressive symptoms in patients with IPD and their caregivers. The Short-Form Health Survey instrument (SF-36) was used to evaluate quality of life of the patients. The Mini-Mental State Examination (MMSE) was administered to patients to evaluate gross cognitive status.

RESULTS

Seventy-four patients (male, 58.1%) were included in the study. The mean age of patients was 66.18±8.5 and the mean duration of disease was 67.23±41.8 months. According to the H&Y scale, the patients were divided into two groups; stage I-II as early stage and stage III-V as late stage. Group 1 (H&Y I-II) consisted of 40 patients, and group 2 (H&Y III-V) comprised 34 patients. The mean duration of disease and UPDRS scores were significantly higher in group 2 (p=0.003, p=0.001, respectively). Significant differences were found in group 2 according to BDI. There were significant differences between group 1 and 2 according to SF-36 subdomains such as general health, emotional role, social functioning, pain, and mental health (p=0.019, p=0.038, p=0.005, p=0.004, p=0.014, respectively). However, there were no significant differences between these two groups concerning CB.

CONCLUSION

Although CB was found in 35 (47.3%) caregivers in our study, we found no significant differences between the caregivers of patients with early and late-stage IPD patients. We thought that this might be due to strong family relationships and cultural dynamics in Turkey. Burden was found to be higher in depressive patients' CGs and CGs who had depressive symptoms. It is important to recognize depressive symptoms earlier to protect the relationship between the CG and the patient because the main providers of care are family members.

The relationship between temperament and depression in Parkinson's disease patients under dopaminergic treatment

AIM

The risk factors for depressive symptoms in patients with Parkinson's disease (PD) under dopaminergic drug treatment are unclear. In this study, we examined whether some temperament traits are related to the presence of comorbid depression in PD patients, independent of the characteristics of illness and drug treatment.

METHODS

The participants in this study were 74 patients with idiopathic PD who were already treated with stable doses of levodopa or dopamine agonists. Depressive (n = 20) and non-depressive (n = 52) PD patients were assessed by means of the Unified Parkinson's Disease Rating Scale, Beck Depression Inventory, and Temperament Evaluation of Memphis, Pisa, Paris and San Diego Auto-questionnaire. The doses of levodopa and dopamine agonists were converted into levodopa equivalent daily dose.

RESULTS

The duration of treatment in the depressive group was significantly longer than in the non-depressive group (P = 0.03). The depressive patients had significantly higher scores on the Unified Parkinson's Disease Rating Scale than the non-depressive patients. Depressive (P < 0.0001), cyclothymic (P < 0.0001), anxious (P < 0.0001), and irritable (P = 0.02) temperament scores were significantly higher in depressive than in non-depressive patients. Hyperthymia scores were significantly higher in non-depressive patients than in depressive patients (P = 0.01). Logistic regression analysis revealed that depressive temperament traits (P = 0.03) significantly predicted the diagnosis of depression. In contrast, hyperthymic temperament seemed to be associated with the absence of depression (P = 0.006).

CONCLUSION

Our results indicated that the severity of PD and duration of dopaminergic treatment were not predictive of the development of depression in PD patients. Depressive temperament strongly predicted the development of depression in our sample. Hyperthymic temperament seemed to be associated with patients without depression. We suggest that depressive temperament traits seem to be related to depression, while hyperthymic temperament may have a protective role in the risk of depression in PD patients.