Depression in Parkinson's disease: clinical correlates and outcome

Animal Approaches to Studying Risk Factors for Parkinson's Disease: A Narrative Review

Despite recent efforts to search for biomarkers for the pre-symptomatic diagnosis of Parkinson's disease (PD), the presence of risk factors, prodromal signs, and family history still support the classification of individuals at risk for this disease. Human epidemiological studies are useful in this search but fail to provide causality. The study of well-known risk factors for PD in animal models can help elucidate mechanisms related to the disease's etiology and contribute to future prevention or treatment approaches. This narrative review aims to discuss animal studies that investigated four of the main risk factors and/or prodromal signs related to PD: advanced age, male sex, sleep alterations, and depression. Different databases were used to search the studies, which were included based on their relevance to the topic. Although still in a reduced number, such studies are of great relevance in the search for evidence that leads to a possible early diagnosis and improvements in methods of prevention and treatment.

Depression in Major Neurodegenerative Diseases and Strokes: A Critical Review of Similarities and Differences among Neurological Disorders

Depression and anxiety are highly prevalent in most neurological disorders and can have a major impact on the patient's disability and quality of life. However, mostly due to the heterogeneity of symptoms and the complexity of the underlying comorbidities, depression can be difficult to diagnose, resulting in limited recognition and in undertreatment. The early detection and treatment of depression simultaneously with the neurological disorder is key to avoiding deterioration and further disability. Although the neurologist should be able to identify and treat depression initially, a neuropsychiatry team should be available for severe cases and those who are unresponsive to treatment. Neurologists should be also aware that in neurodegenerative diseases, such as Alzheimer's or Parkinson's, different depression symptoms could develop at different stages of the disease. The treatment options for depression in neurological diseases include drugs, cognitive-behavioral therapy, and somatic interventions, among others, but often, the evidence-based efficacy is limited and the results are highly variable. Here, we review recent research on the diagnosis and treatment of depression in the context of Alzheimer's disease, Parkinson's disease, and strokes, with the aim of identifying common approaches and solutions for its initial management by the neurologist.

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.

Should patients with Parkinson’s disease only visit a neurologist’s office? - a narrative review of neuropsychiatric disorders among people with Parkinson’s disease

Introduction: Parkinson’s disease is a neurodegenerative disease that is often accompanied by disorders such as depression, psychotic disorders, cognitive disorders, anxiety disorders, sleep disorders, impulse control disorders. The aim of the study was to review the literature and present the characteristics of neuropsychiatric disorders occurring in people suffering from Parkinson’s disease, with the specification of the above-mentioned disorders.

Material and method: The literature available on the PubMed platform from 1986 to 2022 was reviewed using the following keywords: Parkinson’s disease, depression, anxiety disorders, psychotic disorders, sleep disorders, cognitive disorders, impulse control disorders. Original studies, reviews, meta-analyzes and internet sources were analyzed.

Results: The above-mentioned neuropsychiatric disorders appear with different frequency among people suffering from Parkinson’s disease and occur at different times of its duration or even precede its onset for many years. The non-motor symptoms in the form of depressed mood, energy loss or changes in the rhythm of the day may result in a delay of appropriate therapy and thus in complications. Neuropathological changes in the course of Parkinson’s disease as well as dopaminergic drugs used in its therapy influence the development of neuropsychiatric disorders.

Conclusions: In order to avoid misdiagnosis, practitioners should use, e.g. scales intended for patients with Parkinson’s disease. To prevent the consequences of the aforementioned disease entities, methods of early diagnosis, determination of risk factors and standardization of the treatment process must be determined. Consistent care for patients with Parkinson’s disease is significant, not only in the neurological field, but also in the psychiatric one.

Depression in Parkinson's Disease: A Narrative Review

Parkinson's disease (PD) is a progressive neurodegenerative age-related disorder that affects the central nervous system (CNS) and is characterized by uncontrollable movements such as shaking, stiffness, and loss of balance and coordination. Depression is a common non-motor manifestation of PD, but unfortunately, depression remains unrecognized and often undertreated. The underlying pathophysiology of depression in PD is complicated, and many studies have been conducted to know the exact cause, but the question remains unanswered.

In this article, we discuss various pathophysiologies by which depression occurs in PD. The most widely accepted theories are neuroinflammation and monoamine oxidase theory. This article also explored the pharmacological treatment of depression in PD; this involves standard antidepressant therapy such as tricyclic antidepressants (TCA), serotonin-norepinephrine reuptake inhibitors (SNRI), selective serotonin reuptake inhibitors (SSRI), and monoamine oxidase inhibitors (MAO); non-pharmacological treatments such as electroconvulsive therapy (ECT), cognitive-behavioral therapy (CBT) have also been discussed. However, physicians hesitate to prescribe antidepressants to patients with PD due to concerns about harmful drug-drug interactions between antidepressants and antiparkinsonian drugs. Despite the complicated link between PD and depression, the co-administration of antidepressants and antiparkinsonian drugs is safe and beneficial when appropriately managed. However, early recognition and initiation of treatment of depression in PD reduces the longitudinal course and improves the cross-sectional picture. This review article also explored the clinical and diagnostic findings and impact on the quality of life of depression in PD.

Predictors of rapid eye movement sleep behavior disorder in patients with Parkinson’s disease based on random forest and decision tree

Background and objectives

Sleep disorders related to Parkinson’s disease (PD) have recently attracted increasing attention, but there are few clinical reports on the correlation of Parkinson’s disease patients with rapid eye movement (REM) sleep behavior disorder (RBD). Therefore, this study conducted a cognitive function examination for Parkinson’s disease patients and discussed the application effect of three algorithms in the screening of influencing factors and risk prediction effects.

Methods

Three algorithms (logistic regression, machine learning-based regression trees and random forest) were used to establish a prediction model for PD-RBD patients, and the application effects of the three algorithms in the screening of influencing factors and the risk prediction of PD-RBD were discussed.

Results

The subjects included 169 patients with Parkinson’s disease (Parkinson’s disease with RBD [PD-RBD] = 69 subjects; Parkinson’s disease without RBD [PD-nRBD] = 100 subjects). This study compared the predictive performance of RF, decision tree and logistic regression, selected a final model with the best model performance and proposed the importance of variables in the final model. After the analysis, the accuracy of RF (83.05%) was better than that of the other models (decision tree = 75.10%, logistic regression = 71.62%). PQSI, Scopa-AUT score, MoCA score, MMSE score, AGE, LEDD, PD-course, UPDRS total score, ESS score, NMSQ, disease type, RLSRS, HAMD, UPDRS III and PDOnsetage are the main variables for predicting RBD, along with increased weight. Among them, PQSI is the most important factor. The prediction model of Parkinson’s disease RBD that was established in this study will help in screening out predictive factors and in providing a reference for the prognosis and preventive treatment of PD-RBD patients.

Conclusions

The random forest model had good performance in the prediction and evaluation of PD-RBD influencing factors and was superior to decision tree and traditional logistic regression models in many aspects, which can provide a reference for the prognosis and preventive treatment of PD-RBD patients.

Depression in Patients with Parkinson's Disease: Current Understanding of its Neurobiology and Implications for Treatment

Depression is one of the most frequent and burdensome non-motor symptoms in Parkinson’s disease (PD), across all stages. Even when its severity is mild, PD depression has a great impact on quality of life for these patients and their caregivers. Accordingly, accurate diagnosis, supported by validated scales, identification of risk factors, and recognition of motor and non-motor symptoms comorbid to depression are critical to understanding the neurobiology of depression, which in turn determines the effectiveness of dopaminergic drugs, antidepressants and non-pharmacological interventions. Recent advances using in vivo functional and structural imaging demonstrate that PD depression is underpinned by dysfunction of limbic networks and monoaminergic systems, depending on the stage of PD and its associated symptoms, including apathy, anxiety, rapid eye movement sleep behavior disorder (RBD), cognitive impairment and dementia. In particular, the evolution of serotonergic, noradrenergic, and dopaminergic dysfunction and abnormalities of limbic circuits across time, involving the anterior cingulate and orbitofrontal cortices, amygdala, thalamus and ventral striatum, help to delineate the variable expression of depression in patients with prodromal, early and advanced PD. Evidence is accumulating to support the use of dual serotonin and noradrenaline reuptake inhibitors (desipramine, nortriptyline, venlafaxine) in patients with PD and moderate to severe depression, while selective serotonin reuptake inhibitors, repetitive transcranial magnetic stimulation and cognitive behavioral therapy may also be considered. In all patients, recent findings advocate that optimization of dopamine replacement therapy and evaluation of deep brain stimulation of the subthalamic nucleus to improve motor symptoms represents an important first step, in addition to physical activity. Overall, this review indicates that increasing understanding of neurobiological changes help to implement a roadmap of tailored interventions for patients with PD and depression, depending on the stage and comorbid symptoms underlying PD subtypes and their prognosis.

The impact of nonmotor symptom burden on sexual function

Sexual dysfunction (SD) is defined as a combination of reduction in libido, and problems with a person's ability to have sex. It is a frequent but neglected and poorly recognized nonmotor symptom (NMS) in Parkinson's disease (PD) which correlates with reduced quality of life (QoL). Hypersexuality forms another spectrum of SD and is an impulse control disorder (ICD) of behavior, which also affects the sexual desires of people with Parkinson's (PwP) and impacts their partner, family, and QoL. NMS occur in various forms and represents a range of symptoms, from cognitive dysfunction to pain and SD, and this chapter explores the relationship of comorbid NMS with SD and also how NMS, motor symptoms, and hypersexuality experienced by patients may impact sexual function in people with Parkinson's (PwP).

Effectiveness of Safinamide over Mood in Parkinson's Disease Patients: Secondary Analysis of the Open-label Study SAFINONMOTOR

INTRODUCTION

Mood disorders are frequent in Parkinson's disease (PD) and a favorable effect of safinamide on mood has been observed. We aimed to analyze the effectiveness of safinamide on mood as a secondary objective from the SAFINONMOTOR (an open-label study of the effectiveness of SAFInamide on NON-MOTOR symptoms in patients with Parkinson's disease) study.

METHODS

SAFINONMOTOR is a prospective open-label single-arm study conducted in five centers from Spain. Patients with PD were required to have at baseline a Non-Motor Symptoms Scale (NMSS) total score of at least 40. In this analysis, the changes from V1 (baseline) to V4 (6 months ± 1 month) in the BDI-II (Beck Depression Inventory-II), NMSS mood/apathy domain, and PDQ-39 (Parkinson's Disease Questionnaire-39) emotional well-being domain were analyzed. Depression was identified and classified (DSM-IV and Judd criteria) at baseline and at the end of follow-up as major depression (MD), minor depression (mD), subthreshold depression (subD), and non-depression (nonD).

RESULTS

Fifty patients with PD were included (age 68.5 ± 9.12 years; 58% women; 6.4 ± 5.1 years from diagnosis) and 44 patients (88%) completed the follow-up at 6 months. The BDI-II total score was reduced by 35.9% (from 15.88 ± 10.46 at V1 to 10.18 ± 6.76 at V4; p < 0.0001). A significant decrease in the NMSS mood/apathy domain and PDQ-39 emotional well-being domain was observed as well (p < 0.0001). At baseline, 52% of the patients presented MD, 34% mD, 12% subD, and 2% nonD whereas at V4 the percentages were 31.8%, 34.1%, 22.7%, and 11.4%, respectively (p = 0.029).

CONCLUSIONS

Safinamide improves mood in patients with PD at 6 months.

Depressive symptoms in elderly patients with Parkinson's disease: frequency and associated factors

Background/aims

Emotional health is an important factor in clinical and functional manifestations of Parkinson's disease. The aim of this study was to correlate clinical features with depressive symptoms in elderly patients with Parkinson's disease.

Methods

A cross-sectional study was conducted. The Geriatric Depression Scale 15 was used to evaluate depressive symptoms, the modified Hoehn and Yahr scale was used to describe the symptom progression of Parkinson's disease and the Parkinson's Disease Questionnaire 39 to assess the quality of life. The Pearson correlation and the chi-square test were used. Significance level was set at 5%.

Results

A total of 81 individuals participated and 48 (60.8%) presented with depressive symptoms. Participants in the moderate stage of Parkinson's disease and women presented a higher frequency of depressive symptoms. Cognition, communication and mobility presented the highest correlation with depressive symptoms.

Conclusions

The participants presented a high frequency of depressive symptoms that is correlated with a decrease in mobility, communication and cognitive functions. It is recommended that the rehabilitation of elderly people with Parkinson's disease should be performed by a multidisciplinary team, whose objectives are to improve mobility, cognition and communication, which can help reduce depressive symptoms and depression in elderly people with Parkinson's disease.

Mood in Parkinson's disease: From early- to late-stage disease

BACKGROUND

Although depression is known to be frequent in Parkinson's disease (PD), it is unclear how mood can change and/or impact on patient's quality of life (QoL) over time. Our aim was to analyze the frequency of depression, mood related factors and the contribution of mood to a patient's QoL perception in regard to disease duration.

METHODS

PD patients recruited from the COPPADIS cohort from January 2016 to November 2017 were included in this cross-sectional study. Three groups were defined: <5 years (Group A); from 5 to <10 years (Group B); ≥10 years (Group C). Analysis with well-planned linear regression models was conducted to determine how different factors contribute to mood (Beck Depression Inventory-II [BDI-II] as dependent variable), to health-related QoL (39-item Parkinson's Disease Questionnaire [PDQ-39SI] as dependent variable) and to global QoL (European Health Interview Survey - Quality of Life Eight-Item Index [EUROHIS-QOL8] as dependent variable).

RESULTS

Six hundred and sixty-three PD patients (62.6 ± 8.9 years old, 59.6% males) were included: Group A, 50.1% (n = 332); Group B, 33.3% (n = 221) and Group C, 16.6% (n = 110). There were no differences between the three groups in terms of the frequency of depressive symptoms nor the frequency of depression type (major vs. minor vs. subthreshold) (p = 0.729). However, the unique percent variance of PDQ-39SI and EUROHIS-QOL8 explained by BDI-II total score was 2 (23.7%) and threefold (26.9%), respectively, in Group C compared to the other two groups. EUROHIS-QOL8 total score provided the highest unique contribution to mood (16.8%).

CONCLUSIONS

Although depression-type frequency does not appear to change over time in PD; the contribution of mood on QoL perception is greater in patients with longer disease duration.

Psychiatric morbidity in patients with idiopathic Parkinson's disease: A cross-sectional study

OBJECTIVE

To evaluate the prevalence of psychiatric comorbidities in patients with idiopathic Parkinson's disease (IPD).

METHODOLOGY

Two hundred and thirty-nine patients with IPD were evaluated on Mini-International Neuropsychiatric Interview PLUS (MINI-PLUS). In addition, patients found to have depression as per the MINI-PLUS were evaluated on Beck Depression Inventory.

RESULTS

One hundred and thirty-five (56.5%) patients had a current psychiatric diagnosis and 59.8% had a lifetime psychiatric diagnosis. As per MINI-PLUS, about two-fifth (39.7%) of patients had suicidality. In 18.8% of patients, suicidality was present in the absence of axis-I psychiatric diagnosis. Among the various psychiatric disorders, the most common disorders included depressive disorders (current: 17.5%; lifetime: 23.8%), anxiety disorders (current: 17.5%; lifetime: 17.5%), and psychotic disorders (current: 11.3%; lifetime: 11.7%).

CONCLUSIONS

More than half of the patients with Parkinson's disease have psychiatric disorders. High prevalence of psychiatric morbidity calls for close liaison between the neurologist and the psychiatric disorders.

On the heterogeneity of depression in Parkinson’s disease

Depression in Parkinson’s disease (PD) is one of the leading manifestations of the disease, which reduces quality of life in patients.

Objective: to compare the clinical features of depression at different stages of PD.

Patients and methods. Examinations were made in 162 PD patients aged 62.14±1.99 years without dementia (PD duration, 5.78±0.58 years; Stage, 2.5±0.6). The Unified PD Rating Scale (UPDRS), the Beck Depression Inventory (BDI), and the Spielberger Inventory, the 16-Item PD Fatigue Scale (PFS-16), and the Starkstein Apathy Scale were examined. Dopaminergic agents (DAAs) were prescribed when movement disorders were insufficiently corrected. Antidepressants were not used during the investigation. The follow-up period was 18 months.

Results and discussion. Depression was detected in 136 (84%) patients. Depression symptoms appeared in 16 (12%) patients within 1–8 years before the onset of motor symptoms (MS), in 37 (27%) in the first 2 years after the onset of MS, in 44 (32%) at Hoehn–Yahr stages 2–3 without motor fluctuations (MFs), and in 39 (29%) at the onset of MF. The most severity of depression was noted in cases of its development at the premotor stage and in the period of MF occurrence. During the follow-up, the manifestations of depression disappeared in 16% of the patients taking a DAA; these were relapsing-remitting in 9%, progressive in 11%, or remained stable in 64%. The patients with depression occurring at the premotor stage had a progressive course of depression and a low DAA efficacy: an increase in severity in 30% of cases despite therapy and a reversal in only 10% of cases (versus 25–45% of those at depression onset in the presence of MS). In cases of depression occurring in the first 2 years after MS onset, its reversal was observed in 45%; the group of patients with depression onset in the presence of MF showed a stable course with slight severity fluctuations in 77.8%.

Conclusion. Depression in PD is a heterogeneous affective disorder. There is a relatively favorable course of depression when the latter occurs in the first two years of MS onset. Along with DAA inefficacy, the more severity of depression is noted when the latter occurs in the premotor phase of PD and at the stage of MF.

The Impact of Sex and Gender on the Multidisciplinary Management of Care for Persons With Parkinson's Disease

The impact of sex and gender on disease incidence, progression, and provision of care has gained increasing attention in many areas of medicine. Biological factors–sex–and sociocultural and behavioral factors–gender–greatly impact on health and disease. While sex can modulate disease progression and response to therapy, gender can influence patient-provider communication, non-pharmacological disease management, and need for assistance. Sex and gender issues are especially relevant in chronic progressive diseases, such as Parkinson's disease (PD), because affected patients require multidisciplinary care for prolonged periods of time. In this perspective paper, we draw from evidence in the field of PD and various other areas of medicine to address how sex and gender could impact PD care provision. We highlight examples for which differences have been reported and formulate research topics and considerations on how to optimize the multidisciplinary care of persons with PD.

Neuropsychiatric aspects of Parkinson disease psychopharmacology: Insights from circuit dynamics

Parkinson disease (PD) is a neurodegenerative disorder with a complex pathophysiology characterized by the progressive loss of dopaminergic neurons within the substantia nigra. Persons with PD experience several motoric and neuropsychiatric symptoms. Neuropsychiatric features of PD include depression, anxiety, psychosis, impulse control disorders, and apathy. In this chapter, we will utilize the National Institutes of Mental Health Research Domain Criteria (RDoC) to frame and integrate observations from two prevailing disease constructions: neurotransmitter anomalies and circuit physiology. When there is available evidence, we posit how unified translational observations may have clinical relevance and postulate importance outside of PD. Finally, we review the limited evidence available for pharmacologic management of these symptoms.

Variation in Recent Onset Parkinson's Disease: Implications for Prodromal Detection

BACKGROUND

The detection of prodromal Parkinson's disease (PD) is desirable to test drugs with neuroprotective potential, but will be affected by known disease variations.

OBJECTIVE

To assess the prevalence of four key non-motor prodromal PD markers, and evaluate the sensitivity of case detection when non-motor screening tools for prodromal PD are implemented in an early clinical PD cohort.

METHODS

Hyposmia (University of Pennsylvania smell identification test ≤15th centile or Sniffin' Sticks at or ≤10th centile corrected for age and sex), rapid-eye movement sleep behaviour disorder (RBD questionnaire >4), constipation (<1 daily spontaneous bowel motion) and depression (Leeds >6) were recorded in recent onset PD cases, and proposed non-motor screening criteria applied.

RESULTS

In 1,719 PD cases, mean age 68.6 years (SD 8.1), 65.5% male, mean disease duration 1.3 years (SD 0.9), 72.2% were hyposmic, 43.3% had RBD, 22.1% depression, and 21.5% constipation. 11.6% of cases had no key non-motor features, 38.8% one, 32.1% two, 15.5% three, and 2.0% all four. Increasing numbers of non-motor features were associated with younger age (p = 0.019), higher motor scores (p < 0.001), more postural instability gait difficulty (PIGD) (p < 0.001), greater cognitive impairment (p < 0.001) and higher total non-motor burden (p < 0.001). Cases with hyposmia alone were younger (p < 0.001), had less severe cognitive (p = 0.006) and other non-motor features (p < 0.001). All screening criteria selected younger patients (p = 0.001, p < 0.001), three of four greater overall non-motor burden (p = 0.005, p < 0.001), and inclusion of RBD more cognitive impairment (p = 0.003, p = 0.001) and PIGD (p = 0.004, p = 0.001).

CONCLUSIONS

Varying sensitivity levels, and age and phenotype selectivity, are found when different non-motor screening methods to detect prodromal PD are applied to an early clinical PD cohort.

[Anxiety and depressive disorders in Parkinson's disease]

This review presents the most recent data of worldwide research on anxiety and depressive disorders in patients with Parkinson's disease. Their characteristics and epidemiology, pathogenetic and clinical features, methods of diagnosis and treatment are presented. Depression occurs in 40-50% of patients with PD, anxiety in 17-43% of patients. Pramipexole, a dopamine agonist, is only one drug recommended for depression treatment. Nortriptyline and desipramine, belonging to the group of tricyclic antidepressants (TCAs), are considered to be possibly effective. There are no clear recommendations for treatment of anxiety. In general, methods of therapy of anxiety and depressive disorders in PD are not well understood which determines the conduct of large-scale studies in the future.

Neuropsychiatric symptoms in untreated Parkinson's disease

Neuropsychiatric and cognitive symptoms are common in Parkinson's disease (PD) and may precede and exceed motor symptoms as major factors impacting disease course and quality of life. Neuropsychiatric symptoms (NPS) in PD are various and are attributed to pathologic changes within multiple brain regions, to psychological stress, and to adverse effects of dopamine replacement therapy. Sleep disorders and mood symptoms such as apathy, depression, and anxiety may antedate the development of motor symptoms by years, while other NPS such as impulse control disorders, psychosis, and cognitive impairment are more common in later stages of the disease. Few studies report on NPS in the early, untreated phase of PD. We reviewed the current literature on NPS in PD with a focus on the early, drug-naive stages of PD. Among these early disease stages, premotor and early motor phases were separately addressed in our review, highlighting the underlying pathophysiological mechanisms as well as epidemiological characteristics, clinical features, risk factors, and available techniques of clinical assessment.

Call to Caution with the Use of Atypical Antipsychotics for Treatment of Depression in Older Adults

Atypical antipsychotics are increasingly being used to manage depression in older adults where these symptoms can often be refractory to first-line treatment with selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs). Unfortunately, atypical antipsychotics can be associated with the development of extrapyramidal symptoms (EPS), with drug-induced parkinsonism (DIP) being the most common movement disorder induced by this class of medication. The management of treatment-resistant depression in older adults is of particular concern as depression is a common feature of idiopathic Parkinson’s disease (IPD) and can manifest prior to the development of motor symptoms. Herein, we discuss the use of atypical antipsychotics for the management of depression in older adults including the risk of DIP and propose that antipsychotics may potentially unmask IPD.

Associated and predictive factors of depressive symptoms in patients with Parkinson's disease

Depression is one of the most common non-motor symptoms in Parkinson's disease (PD). A thorough understanding of factors associated with depressive symptomatology may facilitate early detection and guide future intervention strategies. The objective of the study was to determine associated and predictive factors of depression in patients with PD. Analyses were performed in data of the SCOPA-PROPARK cohort, a 5-year hospital-based longitudinal cohort of over 400 PD patients who have been examined annually. Linear mixed models using data of all patients were used to identify factors associated with longitudinal changes in Beck Depression Inventory (BDI) scores. A survival analysis using data of patients without depression at baseline was performed to identify risk factors for future depression (i.e. BDI ≥ 15). The proportion of patients with depression was approximately 20 % and remained stable during follow-up, with approximately half of cases showing a persistent course. Female gender, more severe disability, more severe motor fluctuations, autonomic and cognitive dysfunction, poorer nighttime sleep and daytime sleepiness were independently associated with higher BDI scores over time. Higher baseline BDI score, daytime sleepiness and a higher levodopa dosage were risk factors for future depression. Depression is common in PD, where it may follow a persistent or non-persistent course. Apart from motor fluctuations and levodopa dose, depressive symptoms in PD are mainly associated with factors of non-dopaminergic origin. This suggests that depression in PD is an inherent consequence of the progressive pathobiology of the disease, which may render its treatment with currently available treatment options difficult.

Sex and Gender Differences in Central Nervous System-Related Disorders

There are important sex differences in the brain that seem to arise from biology as well as psychosocial influences. Sex differences in several aspects of human behavior and cognition have been reported. Gonadal sex steroids or genes found on sex chromosomes influence sex differences in neuroanatomy, neurochemistry and neuronal structure, and connectivity. There has been some resistance to accept that sex differences in the human brain exist and have biological relevance; however, a few years ago, it has been recommended by the USA National Institute of Mental Health to incorporate sex as a variable in experimental and clinical neurological and psychiatric studies. We here review the clinical literature on sex differences in pain and neurological and psychiatric diseases, with the aim to further stimulate interest in sexual dimorphisms in the brain and brain diseases, possibly encouraging more research in the field of the implications of sex differences for treating these conditions.

Association of specific frequency bands of functional MRI signal oscillations with motor symptoms and depression in Parkinson's disease

A novel empirical mode decomposition method was adopted to investigate the dissociative or interactive neural impact of depression and motor impairments in Parkinson’s disease (PD). Resting-state fMRI data of 59 PD subjects were first decomposed into characteristic frequency bands, and the main effects of motor severity and depression and their interaction on the energy of blood-oxygen-level-dependent signal oscillation in specific frequency bands were then evaluated. The results show that the severity of motor symptoms is negatively correlated with the energy in the frequency band of 0.10–0.25 Hz in the bilateral thalamus, but positively correlated with 0.01–0.027 Hz band energy in the bilateral postcentral gyrus. The severity of depression, on the other hand, is positively correlated with the energy of 0.10–0.25 Hz but negatively with 0.01–0.027 Hz in the bilateral subgenual gyrus. Notably, the interaction between motor and depressive symptoms is negatively correlated with the energy of 0.10–0.25 Hz in the substantia nigra, hippocampus, inferior orbitofrontal cortex, and temporoparietal junction, but positively correlated with 0.02–0.05 Hz in the same regions. These findings indicate unique associations of fMRI band signals with motor and depressive symptoms in PD in specific brain regions, which may underscore the neural impact of the comorbidity and the differentiation between the two PD-related disorders.

Effects of dispositional optimism on quality of life, emotional distress and disability in Parkinson's disease outpatients under rehabilitation

This study was performed with the aim of assessing dispositional optimism (DO) in a sample of Parkinson's disease (PD) patients, in order to evaluate its association with clinical outcomes and its impact on rehabilitation. Before entering an outpatient rehabilitation program, 58 participants suffering from idiopathic PD completed the Life Orientation Test-Revised (LOT-R) to evaluate their level of DO, the WHO-5 scale to evaluate their health-related quality of life (HR-QoL), the Hospital Anxiety and Depression Scale (HADS) to identify emotional distress, and the Barthel Index to evaluate their level of disability. All the measures were repeated four months later, at their discharge from the program. Disease stage and severity measures (Unified Parkinson's Disease Rating Scale) were also taken into consideration. Correlations and multivariate regression analyses compared DO with the health-related variables. On admission a high level of DO was found to be associated with less severe disease, a better quality of life (QoL) and lower emotional distress, but not with level of disability (Barthel Index). Consistent results were found at discharge. The level of DO di not change after rehabilitation, while anxiety was significantly reduced, especially in subjects with low LOT-R and high HADS scores. The Barthel Index values significantly improved. At discharge, participants with high DO showed the best improvements in disability and in QoL. Effects of dispositional optimism on quality of life, emotional distress and disability in Parkinson's disease outpatients under rehabilitation In conclusion, a high level of DO was associated with QoL, HADS and UPDRS both on admission and at discharge. The level of DO remained stable after rehabilitation, while disability and anxiety were reduced. Participants with high DO generally had better QoL, and better clinical and psychological performances.

The Natural History of Depression in Parkinson's Disease within 30-Month Follow-Up

Depression is one of the most common and persistent nonmotor syndromes occurring in 35% of patients diagnosed with PD. However, little information is known about the longitudinal study of its natural history of depression in PD. In this study, we identified 110 patients who are diagnosed with idiopathic PD and recruited them for assessing information about their PD related motor and nonmotor symptoms and rating scales. A follow-up evaluation was performed in 103 patients 30 months later. About 66.7% depressed patients at baseline were still depressed at follow-up, and 24.4% had incident depression among subjects without depression at baseline. Greater decline on MMSE (P = 0.029), higher baseline UPDRS-II (P < 0.001) score, change of UPDRS-II (P = 0.026), and female (P < 0.001) were associated with the worsening of HDRS scores. Higher baseline HDRS score (P < 0.001) and greater decline on MMSE (P = 0.001) were related to the occurrence of depression. In conclusion, cognitive decline is a disease related factor of worsening and the occurrence of depression. Activities of Daily Living (ADL) symptoms in PD and female gender may be crucial factors of increasing depressive symptoms.

The relation of sexual dysfunction to depression and anxiety in patients with Parkinson's disease

OBJECTIVE

In this study, we aimed to find out whether sexual dysfunction in patients with Parkinson's Disease (PD) was associated to PD-related disability and whether this relationship was modulated by depressive and anxiety symptoms.

METHODS

Eighty-nine consecutive patients with idiopathic PD who attended to our movement disorders outpatient clinics between January 2011 and June 2014 were included in this study. The diagnosis of PD was confirmed by a movement disorders specialists in Neurology, according to UK Parkinson's Disease Society Brain Bank Criteria. The Unified PD Rating Scale (UPDRS) motor was used to assess motor disability and Hoehn and Yahr stage (H&Y) was used to establish disease severity. Cognitive function was assessed by the Mini-Mental State Examination. Patients were also administered the Hamilton depression (HAMD) and anxiety (HAMA) rating scales. The sexual functions of the patients were rated by applying the Turkish version of the Arizona Sexual Experiences Scale (ASEX).

RESULTS

The mean age at the time of the study visit was 67.74±9.05. Male/female ratio was 1.87. Mean UPDRS total was 29.06±13.96 and mean UPDRS motor was 17.62±9.07. Mean HAMD score was 13.92±10.86, 58.4% of the patients had minor or major depression; and mean HAMA score was 7.94±6.49, 56.2% of the patients had minor or major anxiety. The mean ASEX score was 18.54±7.27 out of a maximum of 30. ASEX total scores were correlated with age, H&Y stage and HAMA scores. Age and also age at onset were correlated with ASEX subdomains except sexual desire. There was no correlation between disease duration and ASEX subdomains. UPDRS motor score was correlated with erection/lubrication. HAMD was only correlated with orgasm satisfaction. HAMA score was correlated with stimulation and orgasm.

CONCLUSION

In patients with PD, there may be a common factor that modulates both depression, anxiety and sexual function. Further studies are needed to clarify the exact relationship.

Psychiatric aspects of Parkinson's disease

Parkinson's disease (PD) is essentially characterized by the motor symptoms in the form of resting tremor, rigidity and bradykinesia. However, over the years it has been recognized that motor symptoms are just the "tip of the iceberg" of clinical manifestations of PD. Besides motor symptoms, PD characterized by many non-motor symptoms, which include cognitive decline, psychiatric disturbances (depression, psychosis and impulse control), sleep difficulties, autonomic failures (gastrointestinal, cardiovascular, urinary, thermoregulation) and pain syndrome. This review evaluates the various aspects of psychiatric disorders including cognitive decline and sleep disturbances in patients with PD. The prevalence rate of various psychiatric disorders is high in patients with PD. In terms of risk factors, various demographic, clinical and treatment-related variables have been shown to be associated with higher risk of development of psychiatric morbidity. Evidence also suggests that the presence of psychiatric morbidity is associated with poorer outcome. Randomized controlled trials, evaluating the various pharmacological and non-pharmacological treatments for management of psychiatric morbidity in patients with PD are meager. Available evidence suggests that tricyclic antidepressants like desipramine and nortriptyline are efficacious for management of depression. Among the antipsychotics, clozapine is considered to be the best choice for management of psychosis in patients with PD. Among the various cognitive enhancers, evidence suggest efficacy of rivastigmine in management of dementia in patients with PD. To conclude, this review suggests that psychiatric morbidity is highly prevalent in patients with PD. Hence, a multidisciplinary approach must be followed to improve the overall outcome of PD. Further studies are required to evaluate the efficacy of various other measures for management of psychiatric morbidity in patients with PD.

Medication adherence in patients with Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder, after Alzheimer's disease, affecting the elderly worldwide. Current therapy for PD is largely based on prescription of drugs that act as either dopamine precursors, dopamine agonists or agents that inhibit key enzymes in the dopamine catabolic pathways. Most of these drugs are administered in tablet or capsule form and can involve multiple daily doses in complex dosing regimens, which contributes to sub-optimal compliance amongst patients. There is evidence to suggest that non-compliance with medications results in perceived poor response to therapy and may ultimately increase direct and indirect health care costs. Medication compliance in PD assumes a particularly important role, given that PD is a progressive, debilitating condition, and once medication is instituted for ameliorating the symptoms of PD, it is lifelong. We included nine research studies in our review of the medical literature, which report the prevalence of significant medication non-compliance in PD, using standard definitions, varies between 10 and 67%. This variation partly reflects differences in defining what clinically significant medication adherence is, the methods used to estimate the scale of the problem and the underlying population heterogeneity. Nevertheless, medication adherence is related to health costs and to the quality of life of patients affected by PD and, indirectly, their carers. Educating patients and their carers is one method of improving patient adherence to therapy. Simplifying drug regimens can also aid in this effort.

Depression in Parkinson's Disease

Objective:

To examine predictive factors associated with onset of depression among individuals diagnosed with Parkinson's disease (PD).

Background:

Depression may precede or follow symptomatic parkinsonism in PD. It is frequently treatable but often overlooked.

Methods:

The clinical series comprised 685 individuals who were diagnosed with PD and followed by one neurologist (RJU) from 1994 to 2007. The primary outcome was time to depression following the onset of PD. Diagnosis of depression was based on clinical assessment of depressive symptoms from patients (and spouse/family/caregiver) and antidepressant usage. A number of demographic, historical and clinical predictive factors were examined, including gender, age at symptomatic onset, disease duration, onset characteristics, clinical ratings, antiparkinsonian medications, cognitive status, depression history, and familial history of PD and other neurodegenerative disorders.

Results:

Seventy-two percent of patients developed depression within ten years of symptomatic PD onset, and the mean time to depression was 7.9 years (median: 5.7 years). Factors associated with depression included longer PD duration, greater impairment in activities of daily living, and positive family history of motor neuron disease (MND).

Conclusions:

A high rate of individuals with PD develop depressive symptoms during the course of the disease. Based on first clinic visit characteristics, most factors examined were not helpful in identifying individuals with an increased risk of depression. However, disease duration, functional limitations and family history of MND should lead clinicians to an increased vigilance for identifying depression.

Major depressive disorder in Parkinson's disease: a cross-sectional study from Sri Lanka

BACKGROUND

Depression is common in Parkinson's disease (PD), and has a significant impact on the functional level of those affected. It is well studied in Western populations but data from Asia is limited. This study aims to estimate the prevalence of depression among PD patients attending a tertiary care outpatient clinic in Sri Lanka and identify potential risk factors.

METHODS

One hundred and four consecutive idiopathic PD patients as defined by the United Kingdom Parkinson's Disease Society Brain Bank Diagnostic Criteria were recruited to the study. An interviewer administered questionnaire, the Hoehn-Yahr staging scale and the Schwab-England Activities of Daily Living Scale (SEADL) were used for assessment. Depression was diagnosed through a semi-structured clinical interview based on DSM-IV-TR criteria and all subjects were rated with the Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

The prevalence of depression in the study population was 37.5%. Among the depressed 12 (30.8%) had mild depression, 21 (53.8%) moderate depression and 6 (15.4%) had severe depression. Depression was significantly associated with the stage of PD, functional impairment, civil status, educational level, caregiver dependence and concomitant diabetes mellitus.

CONCLUSION

A significant proportion of PD patients suffers from depression. The prevalence rate of depression in the sample was similar to that reported in previous studies. Depression in PD is significantly associated with functional impairment.

Influence of depressive symptoms on dopaminergic treatment of Parkinson's disease

Introduction: Depressive symptoms are very common in patients with Parkinson’s disease (PD) and have a significant impact on the quality of life. Dopaminergic medication has been shown to have an influence on the development of depressive symptoms.

Materials and methods: The present study analyzed two groups of non-demented patients with PD, with and without depressive symptoms, and reported the correlations between antiparkinsonian medication [specifically levodopa (l-DOPA) and dopaminergic agonists] with depressive symptoms.

Results: A strong statistically significant positive correlation between l-DOPA dosages and the level of depressive symptoms has been revealed, suggesting that higher l-DOPA dosages correlate with a worsening of depressive status. No significant correlation was found with dopamine agonists.

Discussion: The results of this study show that in patients with PD, higher l-DOPA dosages correlate with worse depressive symptoms. From this point of view, PD patients need to be better diagnosed with respect to depressive symptoms and need additional treatment adjustment when clinical manifestations of depression are present. Clinicians must be aware that dopaminergic drugs are not sufficient to alleviate depressive symptoms.

Gender differences on motor and non-motor symptoms of de novo patients with early Parkinson's disease

The affect of gender differences on clinical presentation of Parkinson's disease (PD) remains controversial. De novo PD subjects were recruited from a trial-based multicenter cohort in clinical sites of Chinese Parkinson Study Group. Demographic information, motor and non-motor symptom measurements were performed by face-to-face interview using specific scales. Scores and frequencies of symptoms were compared between male and female patients, and regression models were used to control the effects of age and disease duration. Totally 428 PD patients were enrolled in this study, and 60.3 % of them were male. Total UPDRS scores were not significantly different between male and female (25.02 ± 12.84 vs. 25.24 ± 13.22, adjusted p = 0.984). No significant gender differences were found on scores for four cardinal motor signs, neither on motor subtypes (PIGD 19.0 vs. 15.9 %, adjusted p = 0.303). Female patients more likely had depressive symptoms (38.8 vs. 27.5 %, adjusted p = 0.023; CES-D score 13.78 ± 10.91 vs. 11.23 ± 9.42, adjusted p = 0.015). Male patients had significantly higher scores for MMSE (28.26 ± 2.21 vs. 27.00 ± 3.38, adjusted p = 0.0001), and lower scores for identification (1.39 ± 1.63 vs. 2.01 ± 2.63, adjusted p = 0.002) in ADAS-cog. No significant differences were found for other non-motor symptoms including motivation problems (male 29.8 % vs. female 30.6 %, adjusted p = 0.760), fatigue (62.6 vs. 70.5 %, adjusted p = 0.140), constipation (37.2 vs. 30.1 %, adjusted p = 0.243), and sleep quality (57.6 vs. 61.3 %, adjusted p = 0.357; PSQI score: 5.62 ± 3.31 vs. 6.10 ± 3.53, adjusted p = 0.133). Female might be more depressed and have worse performance on cognition in early untreated PD patients, but gender differences are not apparent on motor and other non-motor symptoms.

Depression and Parkinson's disease: current knowledge

Depressive disturbances are common in patients with Parkinson's disease (PD) and influence many other clinical aspects of the disease. In addition to causing inherent emotional distress, depressive disorders negatively impact quality of life, motor and cognitive deficits, functional disability, and other psychiatric comorbidities in patients with PD. Knowledge of the pathophysiology of PD depression remains limited. However, clinical studies demonstrate the efficacy of medications and psychotherapies for PD depression, underscoring the importance of their timely detection and concerted management.

Effects of a multimodal exercise program on the functional capacity of Parkinson's disease patients considering disease severity and gender

The purpose of this study was to investigate the effects of a multimodal exercise program (MEP) on the functional capacity of patients with Parkinson's disease (PD) according to disease severity and gender. Fourteen patients with PD participated in the study and were distributed into groups according to 1) stage of disease and 2) gender. Functional capacity was evaluated before and after 6 months of intervention. The overall PD patient group improved their coordination and strength. Men and women improved in strength performance after exercise. Men also improved on coordination. For severity of disease, the unilateral group improved in strength, while the bilateral group improved in strength, balance, coordination and the UPDRS-functional score. In conclusion, a MEP is efficient in improving components of functional capacity in patients with PD, especially in strength. Gender may be considered in the exercise program. Individuals in the bilateral disease group appeared to benefit more from exercise.

Anxiety and depression in Parkinson's disease

OPINION STATEMENT

Anxiety and depression, while very common problems in Parkinson's disease (PD), have not been subject to adequate treatment trials. While a handful of double blind placebo-controlled trials of depression have been published, only a small number of subjects have been enrolled in most of these. There have been no adequate treatment trials of anxiety. Thus, most practitioners base their treatments on what has been published in the general population and their own personal experience. The data suggest that depression is probably treatable in some cases, but there are no data to support any drug treatment of anxiety. Much of the rationale for treating these disorders is based primarily on side effect profiles rather than efficacy and is almost entirely based on anecdotal experience. Although we lack convincing data, we do believe in the pharmacologic treatment of depression and anxiety and choose medications based on side effect profiles, some of which may be useful. We favor the selective serotonin reuptake inhibitors (SSRIs) in general for both depression and anxiety because of their relative freedom from side effects but will often choose mirtazapine if insomnia or weight loss is a problem, clonazepam for anxiety without depression if an SSRI is insufficient or if REM sleep behavior disorder is a problem, or a tricyclic antidepressant if drooling is troubling and the patient is not demented. Alternatively, we use the serotonin and noradrenaline reuptake inhibitor venlafaxine in those who do not tolerate an SSRI. SSRIs cannot be used for anxiety on an as needed basis, whereas short-acting benzodiazepines may be useful for this purpose. Psychosocial treatments of both depression and anxiety have also been under-studied, with probable benefits and a benign adverse effect profile.

A matter of motion or an emotional matter? Management of depression in Parkinson’s disease

Depression is one of the most frequent comorbidities occurring in Parkinson's disease, affecting up to 50% of patients. Depression is associated with severe negative symptoms and has been shown to contribute to an increased rate of decline of both cognitive and motor function, profoundly impacting on the patient's quality of life. The symptoms of depression overlap with the motor features of Parkinson's disease, making detection difficult. Moreover, the lack of specialized screening tools means that depression remains undiagnosed and untreated in a high percentage of patients. However, depression in Parkinson's disease, when identified early, can be effectively treated with a variety of antidepressant medications, improving quality of life and preserving daily function. The focus of this review is to provide an overview of current knowledge regarding depression in Parkinson's disease, followed by a practical discussion addressing the issues of the detection, diagnosis and treatment.

Neuroplasticity and the next wave of antidepressant strategies

Depression is a common chronic psychiatric disorder that is also often co-morbid with numerous neurological and immune diseases. Accumulating evidence indicates that disturbances of neuroplasticity occur with depression, including reductions of hippocampal neurogenesis and cortical synaptogenesis. Improper trophic support stemming from stressor-induced reductions of growth factors, most notably brain derived neurotrophic factor (BDNF), likely drives such aberrant neuroplasticity. We posit that psychological and immune stressors can interact upon a vulnerable genetic background to promote depression by disturbing BDNF and neuroplastic processes. Furthermore, the chronic and commonly relapsing nature of depression is suggested to stem from "faulty wiring" of emotional circuits driven by neuroplastic aberrations. The present review considers depression in such terms and attempts to integrate the available evidence indicating that the efficacy of current and "next wave" antidepressant treatments, whether used alone or in combination, is at least partially tied to their ability to modulate neuroplasticity. We particularly focus on the N-methyl-D-aspartate (NMDA) antagonist, ketamine, which already has well documented rapid antidepressant effects, and the trophic cytokine, erythropoietin (EPO), which we propose as a potential adjunctive antidepressant agent.

The heterogeneity of cognitive symptoms in Parkinson's disease: a meta-analysis

Several studies have reported heterogeneity in cognitive symptoms associated with specific characteristics of patients with Parkinson's disease (PD). Indeed, researchers have characterised subtypes of patients suffering from PD according to various criteria. Those most frequently used are the type of predominant motor symptoms (tremors or non-tremor symptoms), age at onset and presence of depression. Some characteristics, like the predominant motor subtypes, as well as the presence of depression, are more widely used to categorise cognitive differences between patients. The goal of this study was to analyse the impact of the type of predominant motor symptoms and depression on cognition in PD. A meta-analysis of 27 studies (from 1989 to 2012) was carried out to calculate the average effect size of these factors on the most often used cognitive test during those past years to evaluate cognitive skills, the Mini-Mental State Examination. The studies analysed showed significant mean weighted effect sizes on cognition for the type of motor symptoms (d=0.42; 95% CI 0.30 to 0.54) and for depression (d=0.52; 95% CI 0.38 to 0.66). These results suggested that PD participants with non-tremor predominant motor symptoms or with depression had more or more severe cognitive impairments. Identification of different subtypes in PD is important for a better understanding of the cognitive symptoms associated with this disease. Better knowing the impact of different features of PD subgroups could help to design more appropriate treatments for patients with PD.

Reformulating psychological difficulties in people with Parkinson's disease: the potential of a social relational approach to disablism

Research investigating the psychological difficulties experienced by people with Parkinson's disease (PD) is dominated by individualistic neurobiological and psychological perspectives. Therefore, this opinion paper draws on a reformulation of the social model of disability, Thomas' (1999) and (2007) social relational approach to disablism, to offer an alternative way of conceptualising psychological difficulties experienced by people with PD. This opinion paper explores the ways in which socially imposed restrictions and stigma may contribute to psychological difficulties by using Thomas' (2007) concept of psychoemotional disablism. By using the lens of psychoemotional disablism, this paper demonstrates that people with PD can be exposed to stigmatising attitudes and interactions which could contribute to restrictions, feelings of shame, and psychological difficulties such as depression. Accordingly, it is argued that further attention to the link between psychological difficulties and social dimensions of disablism in PD is needed in both research arenas and clinical practice to broaden understandings and interventions for people with PD.

Depression in Parkinson's disease: identification and management

Depression is a common psychiatric comorbidity in Parkinson's disease (PD) and contributes to significant impairments in cognitive, functional, motor, and social performance. This results in reduced quality of life, higher levels of care dependency, and increased caregiver burden. When treating depression, it is important to ensure that the patient's response to treatment will be adequately monitored. This can be accomplished in neurology or primary care settings, or in clinical settings with interdisciplinary treatment teams. Mental health services should be engaged early as a component of ongoing comprehensive care. This article reviews a general approach to treating the pharmacotherapy of depression in PD. Ultimately, clinicians should rely on empiric assessments of known risks and putative benefits to guide treatment decisions and should include a targeted and individualized multimodal approach that utilizes psychotherapeutic interventions along with pharmacologic therapies.

Barriers to exercise in people with Parkinson disease

BACKGROUND

Exercise is known to reduce disability and improve quality of life in people with Parkinson disease (PD). Although barriers to exercise have been studied in older adults, barriers in people with chronic progressive neurological diseases, such as PD, are not well defined.

OBJECTIVE

The purpose of this study was to identify perceived barriers to exercise in people with PD.

DESIGN

The study had a cross-sectional design.

METHODS

People who had PD, dwelled in the community, and were at stage 2.4 on the Hoehn and Yahr scale participated in this cross-sectional study (N=260; mean age=67.7 years). Participants were divided into an exercise group (n=164) and a nonexercise group (n=96). Participants self-administered the barriers subscale of the Physical Fitness and Exercise Activity Levels of Older Adults Scale, endorsing or denying specific barriers to exercise participation. Multivariate logistic regression analysis was used to examine the contribution of each barrier to exercise behavior, and odds ratios were reported.

RESULTS

Three barriers were retained in the multivariate regression model. The nonexercise group had significantly greater odds of endorsing low outcome expectation (ie, the participants did not expect to derive benefit from exercise) (odds ratio [OR]=3.93, 95% confidence interval [CI]=2.08-7.42), lack of time (OR=3.36, 95% CI=1.55-7.29), and fear of falling (OR=2.35, 95% CI=1.17-4.71) than the exercise group.

LIMITATIONS

The cross-sectional nature of this study limited the ability to make causal inferences.

CONCLUSIONS

Low outcome expectation from exercise, lack of time to exercise, and fear of falling appear to be important perceived barriers to engaging in exercise in people who have PD, are ambulatory, and dwell in the community. These may be important issues for physical therapists to target in people who have PD and do not exercise regularly. The efficacy of intervention strategies to facilitate exercise adherence in people with PD requires further investigation.

Neurosteroid and neurotransmitter alterations in Parkinson's disease

Parkinson's disease (PD) is associated with a massive loss of dopaminergic cells in the substantia nigra leading to dopamine hypofunction and alteration of the basal ganglia circuitry. These neurons, are under the control, among others, of the excitatory glutamatergic and inhibitory γ-aminobutyric acid (GABA) systems. An imbalance between these systems may contribute to excitotoxicity and dopaminergic cell death. Neurosteroids, a group of steroid hormones synthesized in the brain, modulate the function of several neurotransmitter systems. The substantia nigra of the human brain expresses high concentrations of allopregnanolone (3α, 5αtetrahydroprogesterone), a neurosteroid that positively modulates the action of GABA at GABAA receptors and of 5α-dihydroprogesterone, a neurosteroid acting at the genomic level. This article reviews the roles of NS acting as neuroprotectants and as GABAA receptor agonists in the physiology and pathophysiology of the basal ganglia, their impact on dopaminergic cell activity and survival, and potential therapeutic application in PD.

Clinical aspects of palliative care in advanced Parkinson's disease

Parkinson's disease (PD) is one of the most common neurodegenerative disorders of the elderly population. Few therapeutic options are available for patients with PD requiring palliative care. Treatment of the early stages of PD is entirely different from later stages. During the later stages, the palliative care model is introduced to provide the patient with comfort and support. Early palliative care in PD requires minimization of dyskinesias and decreasing occurrence of motor and non-motor off times in an effort to maximize independent motor function. In the later stages, the focus of treatment shifts to treating the predominant non-motor symptoms and having a more supportive and palliative nature. The purpose of this review is to provide a summary of the palliative care management issues and palliative care management options of end-stage PD patients.