Anxiety Symptoms in Australian Memory Clinic Attendees with Cognitive Impairment: Differences Between Self-, Carer-, and Clinician-Report Measures.

OBJECTIVES: To identify the prevalence of anxiety symptoms using a variety of instruments in an Australian memory clinic sample. METHODS: This is an exploratory cross-sectional study using a purposive consecutive series sample of 163 individuals and their carers who attended a Brisbane, Australia, memory clinic in 2012-2015. Descriptive statistics and correlation analyses were performed to explore different approaches to measuring anxiety in the sample, using clinician-rated, self-report and carer-report measures. RESULTS: The mean age of participants was 78 years, nearly 53% were females. Over 70% of participants with mild cognitive impairment (MCI) and dementia (n = 163) experienced mild to moderate anxiety per a clinician-rated measure (HAM-A), which moderately correlated with carer-report anxiety (IQAD; rs =.59, p < .001). Only weak correlations of these measures with self-report anxiety (GAI) were detected. CONCLUSIONS: Mild to moderate anxiety symptoms were frequent in memory clinic attendees diagnosed with MCI or dementia using the HAM-A, suggesting experiences of subclinical anxiety symptoms. CLINICAL IMPLICATIONS: Self- as well as carer-report screening tools should be used in memory clinics in addition to routinely administered neuropsychiatric assessments to support early identification of anxiety symptoms and mapping of available post-diagnostic care pathways for people diagnosed with cognitive impairment.

How Well Do Caregivers Detect Depression and Anxiety in Patients With Parkinson Disease?

Depression and anxiety are prevalent in Parkinson disease (PD) yet underrecognized in clinical practice. Caregiver reports are frequently utilized to aid in the assessment of neuropsychiatric symptoms but little is known about caregivers' ability to recognize them in patients with PD. This study sought to examine the accuracy of caregiver reports. Eighty patient-caregiver dyads were involved. Accuracy of caregiver recognition was assessed by examining the level of agreement between caregiver ratings on the Neuropsychiatric Inventory and patients' diagnosis of depression and anxiety on the Mini-International Neuropsychiatric Interview (MINI)-Plus. The agreement between caregiver report and MINI-Plus diagnosis was low for both depression (6.3%) and anxiety (17.5%). The presence of depression was overreported, while anxiety was largely underestimated by caregivers. Caregiver distress significantly predicted inaccurate caregiver identification of depression ( R2 = .51, P < .001) and anxiety ( R2 = .08, P < .05). Results indicate that caregivers may be poor at recognizing depression and anxiety in patients with PD. Utilization of caregiver report should take into account potential biases that affect caregiver judgment.

A Neurophysiological Study of Semantic Processing in Parkinson's Disease.

OBJECTIVES: Cognitive-linguistic impairments in Parkinson's disease (PD) have been well documented; however, few studies have explored the neurophysiological underpinnings of semantic deficits in PD. This study investigated semantic function in PD using event-related potentials. METHODS: Eighteen people with PD and 18 healthy controls performed a semantic judgement task on written word pairs that were either congruent or incongruent. RESULTS: The mean amplitude of the N400 for new incongruent word pairs was similar for both groups, however the onset latency was delayed in the PD group. Further analysis of the data revealed that both groups demonstrated attenuation of the N400 for repeated incongruent trials, as well as attenuation of the P600 component for repeated congruent trials. CONCLUSIONS: The presence of N400 congruity and N400 repetition effects in the PD group suggests that semantic processing is generally intact, but with a slower time course as evidenced by the delayed N400. Additional research will be required to determine whether N400 and P600 repetition effects are sensitive to further cognitive decline in PD. (JINS, 2017, 23, 78-89).

Cognitive Behavior Therapy for Anxiety in Parkinson's Disease: Outcomes for Patients and Caregivers.

OBJECTIVE: Anxiety negatively impacts the quality of life of Parkinson's disease (PD) patients and caregivers. Despite high prevalence, there is a paucity of trials investigating effective treatments for anxiety in PD. This uncontrolled study investigated the use of a manualized and tailored Cognitive Behavior Therapy (CBT) for anxiety in PD. METHODS: Participants completed 6 weekly CBT sessions. Pre-, post- and follow-up (3 and 6 months) assessments were made. Change in outcomes were analysed using t-tests and Reliability Change Index. Of 17 PD patients who agreed to CBT, 12 completed the intervention. RESULTS: This study showed a significant reduction in Hamilton Anxiety Rating Scale scores in PD immediately post CBT (t(11) = 3.59, p < .01), maintained at 3-month (t(8) = 2.83, p = .02) and 6-month (t(7) = 2.07, p = .04) follow-up. A reduction in caregiver burden (t(11) = 2.68, p = .03) was observed post intervention. Improvements in motor disability (t(11) = 2.41, p = .04) and cognitive scores (t(11) = -2.92, p = .01) were also observed post intervention and at follow-up. CONCLUSIONS: Tailored CBT can be used to treat anxiety in PD. CLINICAL IMPLICATIONS: This study provides preliminary evidence suggesting that tailored CBT reduces anxiety in PD with persisting benefits, and lowers caregiver burden.

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

OBJECTIVE: Prevalence rates of anxiety disorders in Parkinson's 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. METHODS: Using PubMed, we carried out a systematic literature search for studies reporting Diagnostic and Statistical Manual-defined anxiety disorders or clinically relevant anxiety symptoms assessed by an anxiety rating scale. RESULTS: A total of 49 articles were included and assessed for quality, and 45 articles fulfilled the quality criteria. The average point prevalence of anxiety disorders in PD was 31%, with nonepisodic anxiety being more prevalent than episodic anxiety. Generalized anxiety disorder was the most frequent in 14%, followed by social phobia (13.8%), anxiety not otherwise specified (13.3%), and specific phobia (13.0%). Panic disorder with or without phobia was present in 6.8% of PD patients. Of the patients, 31% fulfilled the criteria for current multiple anxiety disorders. Based on anxiety rating scale cutoff scores, clinically significant anxiety symptoms were present in a weighted average of 25.7%. CONCLUSION: This systematic review confirms that anxiety, although often unrecognized, is very common and highlights the need for efficient identification of anxiety in PD. © 2016 International Parkinson and Movement Disorder Society.

Adapting psychotherapy for older patients with Parkinson's disease.

BACKGROUND: Emotional distress associated with Parkinson's disease (PD) increases disease burden and decreases functioning. The literature supports the benefits of psychological interventions for amelioration of emotional distress in persons with PD. The objective of this study is to apply the Contextual Adult Lifespan Theory for Adapting Psychotherapy (CALTAP) to enhancing psychological treatment for persons with PD. METHODS: This paper uses case examples to demonstrate the usefulness of the CALTAP model in helping patients and clinicians separate disease symptoms from the aging process. The examples also illustrate how working in this way can be beneficial in reducing emotional distress in persons with PD. RESULTS: CALTAP contributes to helping persons with PD and persons treating them understand the effects of the disease, separate disease effects from aging processes, and think through the influences of social context, cohort effects, and cultural differences. CONCLUSIONS: The CALTAP model can guide adaptations to psychological interventions for emotional distress in PD and potentially improve their effects.

Disease-specific anxiety symptomatology in Parkinson's disease.

BACKGROUND: Symptoms of anxiety relating to Parkinson's 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.

Anxiety rating scales in Parkinson's disease: a critical review updating recent literature.

BACKGROUND: Assessing anxiety in Parkinson's disease (PD) has been a recent focus, and a number of studies have extensively investigated the validity of anxiety rating scales in PD. The present review aims to provide an overview of anxiety scales widely used and/or validated in PD, and to highlight recommendations for future research required in this area. METHODS: A literature search was performed using terms such as Parkinson* disease, psychiatric, depress*, anxiety, assessment, scales, and valid* in PsycInfo, PubMed, and Web of Science databases. Validation studies and reviews focussed on assessment of anxiety in PD were included. RESULTS: The literature search identified nine anxiety rating scales. The new Parkinson's Anxiety Scale (PAS) showed good psychometric properties. Having a simple design appropriate for older adults and items focussed on cognitive anxiety, the Geriatric Anxiety Inventory (GAI) also appeared promising for use in PD. The Beck Anxiety Inventory (BAI), Hospital Anxiety and Depression Scale, and Hamilton Anxiety Rating Scale (HAM-A) did not demonstrate satisfactory psychometric characteristics when used in PD, while other scales had limited or no evidence of validity or reliability to infer judgments. CONCLUSIONS: PAS and GAI are can be recommended for use in PD without dementia. Usefulness of these scales to assess anxiety in dementia should be examined in the future. Moreover, the complex symptomatology of anxiety relating to "off" PD medication states were not addressed in these scales. Further research is required to develop an anxiety scale tailored for PD.

Anxiety disorders in Parkinson's disease: prevalence and risk factors.

Anxiety disorders are common in Parkinson's disease (PD) patients, yet are poorly studied. We examined the prevalence of anxiety disorders in PD, investigated the association between anxiety, and presentation and progression of PD, and studied for the first time the contribution of putative risk factors for anxiety in PD. A case-series of 79 PD patients recruited from neurology out-patient clinics was examined for anxiety disorders using the DSM-IV criteria. The Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr Staging of PD were employed to understand the relationship between anxiety disorders, and the clinical presentation and severity of PD. A validated survey assessed putative risk factors for anxiety in PD. Twenty-five percent of PD patients were diagnosed with anxiety. Panic disorder, generalised anxiety disorder and social phobia were prevalent anxiety disorders. Comorbid depression with anxiety was observed (14%). The severity but not the duration of PD was positively related to anxiety. PD patients with postural instability and gait dysfunction symptom clustering were more likely to experience anxiety than tremor-dominant patients. While levodopa dosage had no relationship to anxiety, experience of dyskinesias or on/off fluctuations increased the risk. Lateralisation of PD had no association with anxiety. Anxiety disorders decreased with age and young onset PD patients were more likely to experience anxiety than the late onset subjects. Anxiety adds to the complexity of PD, lowering patients' quality of life. Future research can be directed to identify reactive and organic nature of anxiety in PD.

Unmasking neurobiological commonalities between addictive disorders and impulse control disorders in Parkinson's disease.

Changes in reward circuitry have been studied extensively in substance and behavioural addictions. However, comparatively little is known about the neurobiology underlying impulse control disorders (ICDs) in Parkinson's disease, which show roughly similar risk factors and behavioural presentations to both stimulant and behavioural addictions. ICDs occur in a subset of susceptible patients with Parkinson's disease (PD) following intake of dopamine replacement therapy (DRT). These behavioural disorders often have debilitating effects on a patient's quality of life and increase caregiver burden. This comprehensive review examined findings of 40 neuroimaging studies of ICDs in PD to determine (a) whether there are putative neurobiological commonalities between traditional substance and behavioural addictions and DRT-induced ICD in PD and (b) opportunities for future studies to advance current neurobiological understanding of the phenomenon. Results revealed that strikingly similar (a) deficits in dopaminergic receptor expression, (b) connectivity changes in corticostriatal circuitry and (c) neural responses to cue exposure are observed in both ICDs in PD and addictive disorders. These findings point to the value of adopting a transdiagnostic approach when studying addicted populations and pave the way for demystifying this peculiar, often-devastating phenomenon in PD that has so far proven extremely difficult to treat and predict with any precision.

Psychosocial factors and perceived tremor disability in essential tremor.

Growing evidence suggests that patients with essential tremor (ET) show impairment in psychosocial functions and subsequently increasing vulnerability to anxiety. Here we review evidence supporting a positive relationship between self-reported motor disability and psychological symptoms in ET and critically analyze evidence suggesting how psychosocial factors enhance tremor disability in ET. Theories related to motor competency, behavioral conditioning, and social anxiety have been proposed to relate self-concepts to self-reported tremor disability. We review these theories and then propose a new model in an effort to focus on the self-concepts among ET patients as a factor in tremor disability. Patients with ET exhibited cognitive abnormalities, depression, anxiety, and a higher prevalence of avoidant personality types. Although anxiety, depression and personality types may influence tremor disability in ET, self-concepts may better explain perceived tremor disability in social situations. We conclude by discussing a proposed biopsychosocial model and suggesting future research on ET specific assessment tools and intervention methods.

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 Parkinson's 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.

Source activity during emotion processing and its relationship to cognitive impairment in Parkinson's disease.

BACKGROUND: Neural mechanisms contributing to an underlying cognitive impairment in Parkinson's disease (PD) are poorly understood. An effective method to probe cognitive processing deficits in PD is the examination of brain activity during emotional processes, particularly in explicit language emotion recognition contexts. METHODS: The present study utilised cortical source imaging of event related potentials (ERP) from electroencephalography (EEG) to evaluate valence judgements on negative and neutral target words in an automatic affective priming paradigm. Fifty non-demented PD patients, unmedicated for depression or anxiety, completed affective priming tasks during EEG monitoring. Cognitive impairment was measured using the validated Parkinson's Disease-Cognitive Rating Scale (PD-CRS). RESULTS: Results reveal that compared to healthy age-matched controls, PD patients demonstrate a reduced N400 activation during affective priming tasks in bilateral regions of the middle frontal gyrus (MFG), inferior parietal lobule (IPL) and, notably, have a late wave ERP component (LPP) in left MFG, present between 600 and 800 ms, following family-wise error correction (pFWE < 0.05). LPP in PD patients were significantly associated with PD-CRS scores. LIMITATIONS: Although affective priming paradigms are an effective means for various domains of cognition, it is not a focused cognitive behavioural test for cognitive dysfunction. Our study is thus limited to a surrogate measure of cognitive dysfunction via examination of emotional word processing cues. CONCLUSIONS: These findings suggest that source imaging methods with ERP paradigms in PD are effective in identifying delayed cognitive processes in PD.

The CuePed Trial: How Does Environmental Complexity Impact Cue Effectiveness? A Comparison of Tonic and Phasic Visual Cueing in Simple and Complex Environments in a Parkinson's Disease Population with Freezing of Gait.

BACKGROUND: The optimal prescription of cueing for the treatment of freezing of gait (FoG) in Parkinson's disease (PD) is currently a difficult problem for clinicians due to the heterogeneity of cueing modalities, devices, and the limited comparative trial evidence. There has been a rise in the development of motion-sensitive, wearable cueing devices for the treatment of FoG in PD. These devices generally produce cues after signature gait or electroencephalographic antecedents of FoG episodes are detected (phasic cues). It is not known whether these devices offer benefit over simple (tonic) cueing devices. METHODS: We assembled 20 participants with PD and FoG and familiarized them with a belt-worn, laser-light cueing device (Agilitas™). The device was designed with 2 cueing modalities-gait-dependent or "phasic" cueing and gait-independent or "tonic" cueing. Participants used the device sequentially in the off, phasic, or tonic modes, across 2 tasks-a 2-minute walk and an obstacle course. RESULTS: A significant improvement in mean distance walked during the 2-minute walk test was observed for the tonic mode (127.3 m) compared with the off (111.4 m) and phasic (116.1 m) conditions. In contrast, there was a nonsignificant trend toward improvement in FoG frequency, duration, and course time when the device was switched from off to tonic and to phasic modes for the obstacle course. CONCLUSIONS: Parkinson's disease patients with FoG demonstrated an improvement in distance walked during the two-minute walk test when a cueing device was switched from off to phasic and to tonic modes of operation. However, this benefit was lost when patients negotiated an obstacle course.

Depression symptomatology correlates with event-related potentials in Parkinson's disease: An affective priming study.

BACKGROUND: Depression is a predominant non-motor symptom of Parkinson's disease (PD), which is often under recognised and undertreated. To improve identification of depression in PD it is imperative to examine objective brain-related markers. The present study addresses this gap by using electroencephalography (EEG) to evaluate the processing of emotionally valanced words in PD. METHODS: Fifty non-demented PD patients, unmedicated for depression or anxiety, completed an affective priming task while EEG was simultaneously recorded. Prime and target word pairs of negative or neutral valence were presented at a short 250 ms stimulus onset asynchrony. Participants were asked to evaluate the valence of the target word by button press. Depression was measured using an established rating scale. Repeated measures analysis of covariance and correlational analyses were performed to examine whether event-related potentials (ERP) varied as a function of depression scores. RESULTS: Key ERP findings reveal reduced responses in parietal midline P300, N400 and Late Positive Potential (LPP) difference waves between congruent and incongruent neutral targets in patients with higher depression scores. LIMITATIONS: Comparisons of ERPs were limited by insufficient classification of participants with and without clinical depression. A majority of PD patients who had high depression scores were excluded from the analysis as they were receiving antidepressant and/or anxiolytic medications which could interfere with ERP sensitivity. CONCLUSIONS: The present study suggests that the Pz-P300, N400 and LPP are ERP markers relates to emotional dysfunction in PD. These findings thus advance current knowledge regarding the neurophysiological markers of a common neuropsychiatric deficit in PD.

Lexical ambiguity resolution during sentence processing in Parkinson's disease: An event-related potential study.

Event-related potentials (ERPs) were recorded to investigate lexical ambiguity resolution during sentence processing in 16 people with Parkinson's disease (PD) and 16 healthy controls. Sentences were presented word-by-word on computer screen, and participants were required to decide if a subsequent target word was related to the meaning of the sentence. The task consisted of related, unrelated and ambiguous trials. For the ambiguous trials, the sentence ended with an ambiguous word and the target was related to one of the meanings of that word, but not the one captured by the sentence context (e.g., 'He dug with the spade', Target 'ACE'). Both groups demonstrated slower reaction times and lower accuracy for the ambiguous condition relative to the unrelated condition, however accuracy was impacted by the ambiguous condition to a larger extent in the PD group. These results suggested that PD patients experience increased difficulties with contextual ambiguity resolution. The ERP results did not reflect increased ambiguity resolution difficulties in PD, as a similar N400 effect was evident for the unrelated and ambiguous condition in both groups. However, the magnitude of the N400 for these conditions was correlated with a measure of inhibition in the PD group, but not the control group. The ERP results suggest that semantic processing may be more compromised in PD patients with increased response inhibition deficits.

N400 and emotional word processing in Parkinson's disease.

OBJECTIVE: Emotional and cognitive disturbances are common complications in Parkinson's disease (PD). N400 is an event related potential (ERP) strongly linked to lexical-semantic processing and has demonstrated alterations in amplitude and latency when PD patients performed semantic priming tasks. The present study investigated the role of N400 in an automatic affective priming paradigm in PD. Other ERP components relevant to emotion processing were also examined. METHOD: Twenty-two PD patients and 17 healthy adults performed an automatic affective priming task while ERPs were recorded using 128 channels. Prime-target word pairs of negative or neutral valence were presented at a stimulus onset asynchrony of 250 ms. Participants were asked to evaluate the valence of the target word by button press. RESULTS: A larger N400 amplitude for incongruent compared with congruent neutral targets was observed at right central and parietal regions and did not differ between PD and controls. PD and controls also displayed larger P300 and late positive potential (LPP) amplitudes for negative compared with neutral targets at central parietal and right frontal regions. In contrast, whereas controls showed a larger slow negative wave (SNW) for negative targets compared with neutral targets at left frontal and left central regions, PD group demonstrated a significant reduction in SNW amplitude difference at the left central region. CONCLUSION: N400 is intact in PD when processing evaluative judgments of emotional words. P300 and LPP were also intact in PD. The altered left central SNW in PD suggests an ERP marker for emotional dysfunction in PD. (PsycINFO Database Record

Anxiety is associated with cognitive impairment in newly-diagnosed Parkinson's disease.

INTRODUCTION: Anxiety and mild cognitive impairment (MCI) are prevalent non-motor manifestations of Parkinson's disease (PD). While few studies have demonstrated a possible link between cognitive dysfunction and anxiety in PD, to our knowledge, no studies have directly examined the association between them. This study investigated the association between anxiety and cognitive deficits in newly diagnosed PD patients. METHODS: Patients with newly diagnosed PD (N = 185) were recruited from community and outpatient clinics. Anxiety was assessed using the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) clinician rated anxiety item, which has previously been validated against a standardized criteria for the diagnosis of anxiety disorders in PD. Participants scoring ≥2 were classified as anxious. A threshold of 1 SD below normative values (obtained from controls) was used to define cognitive impairment. Impairments in specific cognitive domains were identified as being >1 SD below controls in ≥1 test per domain. RESULTS: After controlling for age, education and motor severity, patients with anxiety were three times more likely to have cognitive impairment compared to those without anxiety (OR = 3.0, 95% CI = 1.2-7.3, p < 0.05). Patients with anxiety were more than twice as likely to be classified as having cognitive impairment due to impairment in the memory domain compared with PD without anxiety (OR = 2.3, 95% CI = 1.0-5.1, p < 0.05), whilst no associations were found between anxiety and performance on other cognitive domains. CONCLUSION: This study shows an association between anxiety and cognitive impairment (specifically memory impairment). Examining the neural basis of this association warrants future research in this developing field.

Mindfulness for Motor and Nonmotor Dysfunctions in Parkinson's Disease.

Background. Motor and nonmotor symptoms negatively influence Parkinson's disease (PD) patients' quality of life. Mindfulness interventions have been a recent focus in PD. The present study explores effectiveness of a manualized group mindfulness intervention tailored for PD in improving both motor and neuropsychiatric deficits in PD. Methods. Fourteen PD patients completed an 8-week mindfulness intervention that included 6 sessions. The Five Facet Mindfulness Questionnaire (FFMQ), Geriatric Anxiety Inventory, Hamilton Depression Rating Scale, PD Cognitive Rating Scale, Unified PD Rating Scale, PD Quality of Life Questionnaire, and Outcome Questionnaire (OQ-45) were administered before and after the intervention. Participants also completed the FFMQ-15 at each session. Gains at postassessment and at 6-month follow-up were compared to baseline using paired t-tests and Wilcoxon nonparametric tests. Results. A significant increase in FFMQ-Observe subscale, a reduction in anxiety, depression, and OQ-45 symptom distress, an increase in PDCRS-Subcortical scores, and an improvement in postural instability, gait, and rigidity motor symptoms were observed at postassessment. Gains for the PDCRS were sustained at follow-up. Conclusion. The mindfulness intervention tailored for PD is associated with reduced anxiety and depression and improved cognitive and motor functioning. A randomised controlled trial using a large sample of PD patients is warranted.

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

Depression is a prominent non-motor symptom in Parkinson's 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.