N. Dissanayaka

The clinical spectrum of anxiety in Parkinson's disease

Anxiety is common in Parkinsons disease (PD), and contributes to increased disability and poorer quality of life. In spite of its significant impact, the symptomatology, chronology, and neurobiology of anxiety in PD are all poorly understood, and this hinders accurate diagnosis and development of effective treatment strategies. This review investigates and updates literature related to the clinical spectrum of anxiety in PD. The reported prevalence of anxiety in PD varies considerably, with emerging interest in the frequency of the DSM‐IV residual category of “Anxiety disorder, not otherwise specified” (Anxiety disorder NOS), which is observed in up to 25% of PD patients. By design, there are no standardized diagnostic criteria for Anxiety disorder NOS, because this is the category applied to individuals who do not meet diagnostic criteria for any other current anxiety disorder. Anxiety rating scales incompletely capture anxiety symptoms that relate specifically to PD symptoms and the complications arising from PD therapy. Consequently, these scales have been deemed inappropriate for use in PD, and there remains a need for the development of a new PD‐specific anxiety scale. Research establishing accurate symptom profiles of anxiety in PD is sparse, although characterizing such symptomatology would likely improve clinical diagnosis and facilitate targeted treatment strategies. Research into the neurobiological and psychological underpinnings of anxiety in PD remains inconclusive. Anxiety can precede the onset of PD motor symptoms or can develop after a diagnosis of PD. Further investigations focused on the chronology of anxiety and its relationship to PD diagnosis are required.

Prevalence of anxiety in Parkinson's disease: A systematic review and meta-analysis.

Prevalence rates of anxiety disorders in Parkinsons disease (PD) vary widely, ranging from 6% up to 55%. The aim of this systematic review was to calculate the average point prevalence of anxiety disorders and clinically relevant anxiety symptoms in PD.

Depression rating scales in Parkinson's disease: A critical review updating recent literature

Depression is a prominent non-motor symptom in Parkinsons disease (PD). Assessing depression in PD remains a challenge due to the overlap of somatic symptoms between depression and PD. Other neuropsychiatric manifestations associated with PD, such as cognitive decline, also complicate assessment of depression. Therefore it is critical to investigate the validity of depression rating scales for use in PD. This will allow evaluation of observer- and self-report instruments to be administered in neurologically ill geriatric populations such as PD, and identification of appropriate scales to use in cognitively challenged PD patients. The present review includes all studies examining the validity of depression rating scales in PD. It discusses the usefulness of 13 depression rating scales in PD. The clinician-rated and widely used HAMD-17 and the self-report GDS scales are recommended for screening and measuring severity of depression in PD. The GDS-15 may be a preferred choice due to its brevity and ease of use design for older adults. Other valid and reliable instruments to use in PD include self-rated scales, such as the HADS-D, HDI, and the BDI, and the observer-report, MADRS. The CSDD displayed satisfactory validity and reliability for identification of PD patients with and without dementia. The PHQ-2, PHQ-10, SDS, CES-D, UPDRS-Depression item, IDS-SR, and IDS-C each showed some evidence of validity or reliability, however further research on the psychometric properties of these scales when used in a PD population are required.

Clinical issues in the treatment of anxiety and depression in older adults with Parkinson’s disease

A significant proportion of persons affected by Parkinsons disease (PD) are over age 65 years. Mental health issues are often less a focus of treatment in this population than physical manifestations of the illness. Anxiety or depression alone, as well as comorbid depression and anxiety, are underrecognized in patients with PD and are associated with deleterious effects on physical and interpersonal functioning, negatively impacting quality of life and well‐being. We offer a brief overview of salient clinical points with respect to assessment and treatment approaches to enhance efficacy of the treatment of mental health symptoms in older adults with PD. Cognitive behavior therapy involves the patient learning to overcome behavioral avoidance associated with anxiety and challenge unhelpful negative cognitions. It is suggested that cognitive behavior therapy is an effective approach to treatment of anxiety and depression in PD and should be offered as a treatment to patients.

Validity and reliability of the Geriatric Anxiety Inventory in Parkinson's disease

Aim:  To examine the psychometric properties of a novel anxiety rating scale, the Geriatric Anxiety Inventory (GAI) in Parkinsons disease (PD).

Validity of Hamilton Depression Inventory in Parkinson's Disease

Studies investigating the assessment of depression in Parkinsons disease (PD) are limited. We examined the concurrent validity and the internal consistency of the Hamilton Depression Inventory (HDI) and compared it to the Hamilton and Geriatric Depression Scales. PD patients (n = 79) were recruited from neurology clinics. Diagnosis of depressive disorder was made according to DSM‐IV criteria. Receiver operating characteristic curves were used to calculate sensitivity, specificity, and positive and negative predictive values. The HDI exhibited an optimal cutoff for discriminating between depressed and nondepressed PD patients of 13.5/14.0 and is a valid instrument to use in the setting of PD.

Assessment methods and factors associated with depression in Parkinson's disease

Depression is a common problem experienced by patients with Parkinsons disease (PD). Identifying depression in PD is difficult and the determinants of depression in PD are complex and debatable. Here we review our recent studies which have (i) examined the validity of current depression rating scales in PD, (ii) introduced a self-reported and validated strategy to identify a lifetime history of depression in PD, and (iii) investigated genetic and non-genetic factors associated with depression in the context of PD. Our research showed PD-specific cut-off values suitable to use for the Hamilton Depression Scales (HAMD and HDI) and the Geriatric Depression Scale (GDS-15) when dichotomising patients with and without a current depression. Using the GDS-15 specific cut-off scores and a number of self-reported questions that screen for a lifetime history of depression, we developed a novel method to dichotomise PD patients according to current depression or a past history of depression. This method was applied in a large-scale study examining the factors associated with depression in PD. We clarified that the severity of PD is positively related to depression. We also showed that a number of other clinical factors including a longer duration of PD, a younger PD onset age, frequent falls, a history of anxiety disorder and memory problems were associated with depression in PD. In addition to these clinical factors, we observed associations between depression, and lower education levels, a history of smoking and a regular use of non-aspirin bases NSAIDs or analgesics. No associations were found between depression in PD and common genetic variations examined across the serotonin and dopamine transporter genes. Our studies provide a focus for future intervention strategies.

Serotonin and dopamine transporter genes do not influence depression in Parkinson's disease

Altered levels of the neurotransmitters dopamine and serotonin are observed in both Parkinsons disease (PD) and depression. Therefore, the neurotransmitter transporter genes, SLC6A3 (dopamine) and SLC6A4 (serotonin) are candidates for depression in PD. We genotyped 24 tagging SNPs together with VNTRs and the SLC6A4 LPR polymorphism in 190 PD patients categorised according to lifetime history of depression. Log‐additive, dominant and recessive statistical models were constructed. No significant genotype or haplotype associations were observed suggesting that common genetic variables around the dopamine and serotonin transporter genes do not play a significant role in the etiology of depression in PD.

Compulsive use of dopamine replacement therapy: a model for stimulant drug addiction?

The compulsive use of dopamine replacement therapy (DRT) or dopamine dysregulation syndrome (DDS) is one of the behavioural disturbances reported in some patients with Parkinsons disease (PD) and other disorders who are receiving DRT. We draw this phenomenon to the attention of the addiction field as a topic deserving of more systematic study. We outline: the clinical features, epidemiology and clinical correlates of the disorder; the unresolved issues in its definition and diagnosis; and its potential relevance to neurobiological models of psychostimulant addiction. We argue that compulsive DRT use may provide a useful model for drug addiction, while advancing our understanding of the neurobiology of addiction and improving the management of PD patients with the disorder.

Disease-specific anxiety symptomatology in Parkinson's disease

BACKGROUND Symptoms of anxiety relating to Parkinsons disease (PD) occur commonly and include symptomatology associated with motor disability and complications arising from PD medication. However, there have been relatively few attempts to profile such disease-specific anxiety symptoms in PD. Consequently, anxiety in PD is underdiagnosed and undertreated. The present study characterizes PD-related anxiety symptoms to assist with the more accurate assessment and treatment of anxiety in PD. METHODS Ninety non-demented PD patients underwent a semi-structured diagnostic assessment targeting anxiety symptoms using relevant sections of the Mini International Neuropsychiatric Interview (MINI-plus). In addition, they were assessed for the presence of 30 PD-related anxiety symptoms derived from the literature, the clinical experience of an expert panel and the PD Anxiety-Motor Complications Questionnaire (PDAMCQ). The onset of anxiety in relation to the diagnosis of PD was determined. RESULTS Frequent (>25%) PD-specific anxiety symptoms included distress, worry, fear, agitation, embarrassment, and social withdrawal due to motor symptoms and PD medication complications, and were experienced more commonly in patients meeting DSM-IV criteria for an anxiety disorder. The onset of common anxiety disorders was observed equally before and after a diagnosis of PD. Patients in a residual group of Anxiety Not Otherwise Specified had an onset of anxiety after a diagnosis of PD. CONCLUSION Careful characterization of PD-specific anxiety symptomatology provides a basis for conceptualizing anxiety and assists with the development of a new PD-specific measure to accurately assess anxiety in PD.