Visual vertical neglect in acquired brain injury: a systematic review.

Vertical neglect represents a visuospatial deficit occurring as a possible consequence of acquired brain injury (ABI). Differently from unilateral spatial neglect on horizontal space, vertical neglect is poorly studied in the literature and rarely assessed in clinical practice. In the available studies, the terms "radial," "vertical," and "altitudinal" neglect are often used interchangeably, although they do not describe the same spatial dimension. "Altitudinal" and "vertical" refer to the sagittal plane, whereas "radial" refers to the transverse plane. The term "vertical" is sometimes used interchangeably with respect to both axes. The aim of this systematic review was to identify the main characteristics of vertical neglect after ABI, the diagnostic tools used, and the treatment options. We also proposed a clarification of the manifestations and characteristics of vertical and radial neglect. The 23 articles reviewed, showed that the vertical neglect occurred more frequently on the lower space than on the upper space, that its presence was associated with horizontal neglect, and that it could also occur with compromise of the radial space, with the near radial being more common. The most frequent etiology associated with vertical neglect is vascular, particularly ischaemic. The lesions side are very heterogeneous and include both cortical and subcortical areas and all lobes, although the temporal lobe is most affected. With regard to the assessment tools, paper and pencil tasks are the most commonly used diagnostic tools to identify vertical neglect, although in recent years the use of computer-based tasks increased. Taken together, our results suggest that vertical neglect may be underestimated in patients with right hemisphere lesions and should always be assessed, especially in cases where the patient shows signs of horizontal neglect. The clinical assessment of vertical neglect is very important since it can lead to important functional limitations in everyday life, such as poor wheelchair handling, stumbling over unnoticed obstacles located below (or above), walking down stairs, taking off shoes.

Psychometrics and diagnostics of the Italian version of the Alternate Verbal Fluency Battery (AVFB) in non-demented Parkinson's disease patients.

BACKGROUND: Verbal fluency (VF) tasks are known as suitable for detecting cognitive impairment (CI) in Parkinson's disease (PD). This study thus aimed to evaluate the psychometrics and diagnostics of the Alternate Verbal Fluency Battery (AVFB) by Costa et al. (2014) in an Italian cohort of non-demented PD patients, as well as to derive disease-specific cut-offs for it. METHODS: N = 192 non-demented PD patients were screened with the Montreal Cognitive Assessment (MoCA) and underwent the AVFB-which includes phonemic, semantic and alternate VF tests (PVF; SVF; AVF), as well as a Composite Shifting Index (CSI) reflecting the "cost" of shifting from a single- to a double-cued VF task. Construct validity and diagnostics were assessed for each AVFB measure against the MoCA. Internal reliability and factorial validity were also tested. RESULTS: The MoCA proved to be strongly associated with PVF, SVF and AVF scores, whilst moderately with the CSI. The AVFB was internally consistent and underpinned by a single component; however, an improvement in both internal reliability and fit to its factorial structure was observed when dropping the CSI. Demographically adjusted scores on PVF, SVF and AVF tests were diagnostically sound in detecting MoCA-defined cognitive impairment, whilst this was not true for the CSI. Disease-specific cut-offs for PVF, SVF and AVF tests were derived. DISCUSSION: In conclusion, PVF, SVF and AVF tests are reliable, valid and diagnostically sound instruments to detect cognitive impairment in non-demented PD patients and are therefore recommended for use in clinical practice and research.

Family caregivers improve the diagnostic accuracy of disorders of consciousness: from remote to near-bed auditory stimulation.

BACKGROUND: Family caregivers (FC) contribute to reducing the misdiagnosis rate in patients with disorders of consciousness (DOC). Unfortunately, the recent pandemic of COVID-19 imposed drastic restrictions that limited the access of FC to the sensory/cognitive stimulation protocols. Telemedicine approaches have been implemented to avoid discontinuity in care pathways and to ensure caregivers involvement in rehabilitation programs. AIM: The aim was to investigate whether the presence of FC remotely connected might help clinicians in eliciting higher cortically mediated behavioral responses in patients with DOC. DESIGN: Cross-sectional study. SETTING: Post-acute Unit of Neurorehabilitation. POPULATION: DOC due to severe brain injury. METHODS: Consecutive patients with DOC were assessed by means of the Coma Recovery Scale-Revised (CRS-R) by two expert examiners. Each patient underwent to five assessments in two weeks in three different conditions: 1) by the examiner only (standard); 2) with the verbal stimulation given by the FC remotely connected by PC tablet (caregiver in remote); and 3) with the verbal stimulation given by the FC physically present (caregiver in presence). RESULTS: Thirty patients with DOC (VS/UWS=10; MCS=20; mean age: 51, range: 21-79; vascular: 16; anoxic: 6; TBI=8) and their FC were enrolled. Higher total scores of CRS-R were recorded both in "caregiver in remote" and in "caregiver in presence" than in standard condition (standard vs. remote, Z=2.942, P=0.003; standard vs. presence, Z=3.736, P<0.001). Furthermore, the administration of the CRS-R with a FC, elicited higher levels of behavioral responses in MCS patients, than CRS-R performed in standard condition. In particular, 2 patients out of 30 (6.66%) showed higher scores and better diagnosis when the CRS-R was administered with FC in remote. Similarly, 5 out of 30 patients (16.66%) showed better diagnoses when the CRS-R was administered with FC in presence. Five patients changed diagnosis between standard and presence conditions (3 MCS- were diagnosed as MCS+; 2 MCS+ were diagnosed as conscious). CONCLUSIONS: Our findings add new evidence regarding the beneficial role of family members in the diagnosis of DOC, even mediated by telemedicine approach. CLINICAL REHABILITATION IMPACT: In future guidelines, FC should have an active and supporting role in the diagnostic and rehabilitative process of DOC.

Anatomical correlates of apathy and impulsivity co-occurrence in early Parkinson's disease.

BACKGROUND: Although apathy and impulse control disorders (ICDs) are considered to represent opposite extremes of a continuum of motivated behavior (i.e., hypo- and hyperdopaminergic behaviors), they may also co-occur in Parkinson's disease (PD). OBJECTIVES: We aimed to explore the co-occurrence of ICDs and apathy and its neural correlates analyzing gray matter (GM) changes in early untreated PD patients. Moreover, we aimed to investigate the possible longitudinal relationship between ICDs and apathy and their putative impact on cognition during the first five years of PD. METHODS: We used the Parkinson's Progression Markers Initiative (PPMI) database to identify the co-occurrence of apathy and ICDs in 423 early drug-naïve PD patients at baseline and at 5-year follow-up. Baseline MRI volumes and gray matter changes were analyzed between groups using voxel-based morphometry. Multi-level models assessed the longitudinal relationship (across five years) between apathy and ICDs and cognitive functioning. RESULTS: At baseline, co-occurrence of apathy and ICDs was observed in 23 patients (5.4%). This finding was related to anatomical GM reduction along the cortical regions involved in the limbic circuit and cognitive control systems. Longitudinal analyses indicated that apathy and ICDs were related to each other as well as to the combined use of levodopa and dopamine agonists. Worse apathetic and ICDs states were associated with poorer executive functions. CONCLUSIONS: Apathy and ICDs are joint non-exclusive neuropsychiatric disorders also in the early stages of PD and their co-occurrence was associated with GM decrease in several cortical regions of the limbic circuit and cognitive control systems.

Vocabulary knowledge as a reliable proxy of cognitive reserve in multiple sclerosis: a validation study.

INTRODUCTION: The present study aimed to explore the suitability of the vocabulary knowledge (VOC) test as an accurate and reliable proxy of cognitive reserve (CR) by evaluating its psychometric properties and discrimination accuracy compared with other CR measures in multiple sclerosis (MS). METHODS: Sixty-eight consecutive people with multiple sclerosis (pwMS), followed at our MS outpatient clinic, completed a clinical evaluation and neuropsychological assessment including: VOC, Brief Repeatable Battery of Neuropsychological Tests (BRB-N), Cognitive Reserve Index Questionnaire (CRIq), Beck Depression Inventory-II, and State-Trait Anxiety Inventory. Reliability, convergent and divergent validity, and discrimination accuracy of the VOC were assessed using educational level as reference standard. The possible effects of sociodemographic and clinical factors on VOC and their role in predicting global cognitive status were also explored. RESULTS: VOC demonstrated good internal consistency (Cronbach's α = 0.894) and adequate construct validity. It showed an acceptable level of discrimination between pwMS with high and low CR, comparable to the CRIq score. Education strongly affected VOC scores, which in turn were independent of MS features. VOC emerged as an independent predictor of global cognitive status together with MS-related disability. CONCLUSION: We demonstrated the validity of VOC as a reliable CR measure in pwMS. Thus, CR may also be estimated using fixed objective measures, independent of brain pathology and clinical features. Early CR estimation may help clinicians identify pwMS at a higher risk of cognitive decline and plan strict neuropsychological monitoring and cognitive interventions.

The relation between cognitive functioning and activities of daily living in normal aging, mild cognitive impairment, and dementia: a meta-analysis.

Literature suggests that dementia and, more generally, cognitive impairment affect the capacity to carry out activities of daily living (ADL) in aging. However, it is important to decipher the weight of specific cognitive domains and neurodegenerative profiles mainly related to ADL difficulties. A meta-analysis was conducted to investigate the nature and strength of the association between cognitive functioning and ADL in healthy older adults, mild cognitive impairment (MCI), and dementia. A comprehensive search of the PubMed, PsycINFO (PROQUEST), and Scopus databases for cross-sectional or longitudinal studies up until December 2022. Our meta-analytic results revealed that: overall, instrumental ADL (IADL) showed a significant association with executive functioning, in particular, abstraction ability/concept formation, set-shifting, and processing speed/complex attention/working memory, regardless of type of participants (i.e., healthy older adults, MCI, and dementia); whereas ADL (both basic ADL, BADL, and IADL) significantly correlated with global cognitive functioning and long-term verbal memory, with a moderator effect of clinical condition (e.g., increasing ES based on the level of cognitive impairment). Moreover, visuospatial and language abilities significantly correlated with ADL, mainly when performance-based tasks were used for ADL assessment. These findings emphasize the importance of neuropsychological assessment in aging to early identify people most at risk of functional decline and shed light on the need to consider specific cognitive abilities in rehabilitation programs.

Validation of the Italian version of the Parkinson's Disease- Cognitive Functional Rating Scale.

A key distinguishing factor between mild cognitive impairment (MCI) and dementia in Parkinson's disease (PD) lies in the notable decrease in functioning due to cognitive impairment. The Parkinson's Disease-Cognitive Functional Rating Scale (PD-CRFS) was developed to assess functional limitations caused by cognitive impairment, while reducing the influence of motor impairment. The aim of this multicenter study was to (i) validate the Italian version of the PD-CFRS in PD, (ii) determine optimal cut-off scores for detecting MCI and dementia in PD, (iii) compare its performances with the most established functional assessment tool (IADL). Six hundred and sixty nine PD participants were recruited from 4 Italian Movement Disorders centers (Venice, Milan, Gravedona, and Salerno). They underwent Level-II cognitive evaluation, which resulted in 282 PD-NC, 310 PD-MCI, and 77 PDD. The PD-CFRS's psychometric and clinimetric properties, applicability, and responsiveness were analyzed. The PD-CFRS showed high acceptability. Floor and ceiling effects were acceptable. It also displayed strong internal consistency (Cronbach's α = 0.738), and test-retest reliability (ICC = .854). The PD-CFRS demonstrated higher coefficient of variation to detect dysfunction in PD-MCI patients in comparison to the IADL scale (PD-CFRS 96% vs IADL 22.5%). Convergent validity with the IADL was r = - 0.638 and - 0.527 in males and females, respectively. PD-CFRS total score negatively correlated with global cognition (MoCA corrected score r = - 0.61; p < 0.001). A cut-off score > 6.5 identified PDD with a sensitivity of 90% and specificity of 88% (AUC = .959). A cut-off value of > 1 detected PD-MCI with a sensitivity of 68% and specificity of 69% (AUC = .695). The Italian version of the PD-CFRS demonstrated to be an easy, valid and reliable tool that properly captures functional impairment due to cognitive decline in PD. It also proved to be particularly effective in the advanced stages of PD, and would be a useful support for the diagnosis of PD-MCI and PDD.

Validation of the Italian version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) in an Italian Parkinson's disease cohort.

INTRODUCTION: Impulse control disorders (ICDs) frequently occur in Parkinson's disease (PD), and an early identification is essential to prevent severe psychosocial consequences. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) has been developed to evaluate the severity of ICDs along with a range of impulsive-compulsive behaviors (ICBs) in PD; however, its Italian version has not yet been validated. METHODS: One hundred consecutive outpatients with PD were administered an Italian version of the QUIP-RS and a brief neuropsychological assessment to evaluate global cognitive status and scales to measure depression, apathy and impulsive disorders. We evaluated the internal consistency, convergent and divergent validity, and factorial structure of QUIP-RS. We also explored the possible association between QUIP-RS scores and clinical factors and dopaminergic medication. RESULTS: Subsyndromal ICDs manifestations were observed in 54% of the patients, and one in four (22%) reported two or more ICDs or related behaviors. The QUIP-RS demonstrated good internal consistency (Cronbach's alpha = 0.806) and construct validity, and its factorial structure reflected different ICDs and ICBs domains. No association emerged between QUIP-RS scores and the clinical aspects of PD and dopaminergic medication. CONCLUSION: We provided, for the first time, an Italian translation of the QUIP-RS and demonstrated its feasibility in clinical and research settings. Severity of ICDs was independent of clinical factors and dopaminergic medication, underlining the need to adopt a broader perspective on their etiopathology in PD.

The relationship between depression and cognitive performance in multiple sclerosis: A meta-analysis.

Objective: Studies on the relationship between depression and cognition on patients with multiple sclerosis (MS) are inconsistent and it is not clear whether higher depression levels are associated with impairment of specific cognitive domains or processes. This meta-analytic study aimed at evaluating the possible association between depressive symptomatology and performance on cognitive tests assessing several cognitive domains (global cognition, attention, processing speed, verbal, spatial and working memory, verbal fluency, inhibitory control, set-shifting) in individuals living with MS. Method: The literature search on three electronic databases yielded 5402 studies (4333 after the duplicates removal); after the evaluation of titles, abstracts full-text articles, 37 studies were included in the meta-analytic study. A random-effect model meta-analysis was performed and mean weighted effect sizes (ESs) were calculated using Hedges' g. Results: Small ESs were found for the relationship between depression and verbal memory (g = 0.25, p < 0.001), spatial memory (g = 0.23, p < 0.001), verbal fluency (g = 0.26, p < 0.001), and inhibitory control (g = 0.32, p = 0.003). Medium ESs were found for the relationship between depression and global cognition (g = 0.46, p < 0.001), attention (g = 0.43, p < 0.001), processing speed (g = 0.47, p < 0.001) and working memory (g = 0.38, p = 0.037). The relationship between set-shifting abilities and depression was not significant (g = 0.39, p = 0.095). Conclusions: Results suggest that patients with MS and higher levels of depressive symptomatology may also show more difficulties in several aspects of cognition, especially those needed to retain, respond, and process information in one's environment, and to those needed be adequately stimulated in processing relevant information.

Theory of mind in mild cognitive impairment and Parkinson's disease: The role of memory impairment.

BACKGROUND: Social cognition is impaired in Parkinson's disease (PD). Whether social cognitive impairment (iSC) is a by-product of the underlying cognitive deficits in PD or a process independent of cognitive status is unknown. To this end, the present study was designed to investigate the weight of specific cognitive deficits in social cognition, considering different mild cognitive impairment subtypes of PD (PD-MCI). METHODS: Fifty-eight PD patients underwent a neuropsychological battery assessing executive functions, memory, language, and visuospatial domains, together with social cognitive tests focused on theory of mind (ToM). Patients were divided into subgroups according to their clinical cognitive status: amnestic PD-MCI (PD-aMCI, n = 18), non-amnestic PD-MCI (PD-naMCI, n = 16), and cognitively unimpaired (PD-CU, n = 24). Composite scores for cognitive and social domains were computed to perform mediation analyses. RESULTS: Memory and language impairments mediated the effect of executive functioning in social cognitive deficits in PD patients. Dividing by MCI subgroups, iSC occurred more frequently in PD-aMCI (77.8%) than in PD-naMCI (18.8%) and PD-CU (8.3%). Moreover, PD-aMCI performed worse than PD-CU in all social cognitive measures, whereas PD-naMCI performed worse than PD-CU in only one subtype of the affective and cognitive ToM tests. CONCLUSIONS: Our findings suggest that ToM impairment in PD can be explained by memory dysfunction that mediates executive control. ToM downsides in the amnesic forms of PD-MCI may suggest that subtle changes in social cognition could partly explain future transitions into dementia. Hence, the evaluation of social cognition in PD is critical to characterize a possible behavioral marker of cognitive decline.

Measuring mindreading in preschoolers: The perspective battery (PERBAT).

OBJECTIVE: The capacity to take another person's visual perspective is pivotal for solving mindreading tests, such as Theory of Mind (ToM) tasks, but most of them heavily rely on domain-general abilities (e.g., language, executive functions). Here we present a novel battery of visual perspective-taking tests for child neuropsychological assessment, the Perspective Battery (PERBAT), which poses a limited load on domain-general abilities. METHODS: The battery includes four tests: i) Block Building; ii) Hide and Seek; iii) Deceptive Figures; iv) Double-Sided Shelf. We administered the PERBAT to 126 typically developing preschoolers (65 males; 3-6-year-old); the participants also performed classical tests of social cognition, language, and nonverbal abstract reasoning. RESULTS: The scores of all the PERBAT tests were significantly and positively related with age and scores of the classical social cognition tests, but not with scores of the language and nonverbal abstract reasoning tests. CONCLUSIONS: The PERBAT could represent a useful neuropsychological tool providing a comprehensive assessment of visual perspective-taking skills in preschool children. Future investigation is needed to examine the validity of the PERBAT with neurotypical samples across countries, race, ethnicity, and language as well as with clinical populations. Longitudinal studies are also encouraged to examine whether early visual perspective-taking weaknesses are associated with later development of mindreading skills.

Prevalence and clinical aspects of obstructive sleep apnea in Parkinson disease: A meta-analysis.

BACKGROUND AND PURPOSE: Obstructive sleep apnea (OSA) frequently occurs in Parkinson Disease (PD), probably caused by upper airway dysfunctions or shared pathogenetic mechanisms. OSA may precede PD diagnosis or worsen throughout its course, but its relationship with clinical features and dopaminergic medication remains unclear. This meta-analysis aimed to provide a reliable estimate of OSA prevalence in the PD population (PD-OSA) and to clarify its clinical associated factors to help clinicians in understanding the underlying pathophysiological mechanisms. METHODS: A systematic literature search was performed up to April 2023 using the PubMed, Scopus, and PsycINFO databases. Articles were included if they provided data on PD patients with and without OSA. Pooled prevalence for PD-OSA was calculated using the proportions of PD participants diagnosed with OSA. Demographic and clinical features associated with PD-OSA were explored by comparing PD patients with and without OSA. RESULTS: Seventeen studies were included in the meta-analysis. Pooled OSA prevalence was 45% of a total sample of 1448 PD patients and was associated with older age, male sex, higher body mass index (BMI), more severe motor disturbances and periodic limb movements, reduced risk of rapid eye movement sleep behavior disorder, intake of dopamine agonists, and worse excessive daytime sleepiness. No relationship emerged with cognitive functioning and neuropsychiatric manifestations. CONCLUSIONS: OSA affects nearly half of PD patients as a secondary outcome of predisposing factors such as older age and higher BMI in addition to PD-related motor impairment. Future studies should focus on determining the impact of both clinical features and dopaminergic medication on the development of PD-OSA.

The efficacy of telephone-delivered cognitive behavioral therapy in people with chronic illnesses and mental diseases: A meta-analysis.

COVID-19 pandemic led to an increase of remote treatments, such as telephone-delivery cognitive behavioral therapy (T-CBT). To our knowledge, no meta-analyses studied the effect of T-CBT in chronic and/or mental illnesses on multiple psychological outcomes. Therefore, our study aims to evaluating the efficacy of T-CBT compared to other interventions (treatment as usual, TAU, or face-to-face CBT). Each effect size (ES) was calculated in Hedges' g and pooled together to produce a mean ES for each outcome (depression, anxiety, mental and physical QoL, worry, coping, and sleep disturbances). The meta-analysis included 33 studies with a randomized controlled trial design. A large ES was found when comparing the efficacy of T-CBT against TAU on depression (g = 0.84, p < 0.001), whereas a moderate ES was found on anxiety (g = 0.57; p < 0.001), and a small effect on mental quality of life (g = 0.33, p < 0.001), sleep disturbances (g = 0.37, p = 0.042), coping (g = 0.20, p = 0.016) and worry (g = 0.43, p = 0.001). The meta-analysis comparing the efficacy of T-CBT and CBT on depression revealed a not significant pooled ES (g = 0.06, p = 0.466). The results provided evidence that T-CBT could be to be more effective than TAU conditions in multiple psychological outcomes, and as efficient as face-to-face CBT in treating depression.

Psychometric properties and normative data of the Italian version of the Cognitive Function at Work Questionnaire: a screening tool for detecting subjective cognitive complaints at work.

INTRODUCTION: Considering the extension of working life due to socioeconomic and political factors, many people may experience cognitive complaints (CC) at their workplace, with severe consequences on their quality of life. The identification of workers reporting significative SCC is crucial to eventually address them to an objective neuropsychological evaluation and implement cognitive interventions to guarantee workers' well-being. Since no Italian questionnaires for detecting CC were designed for occupational settings, the aim of the study was to validate the Italian version of the Cognitive Function at Work Questionnaire (CFWQ) and to provide its normative data. MATERIALS AND METHODS: Internal consistency, convergent and divergent validity, and factorial structure of the CFWQ were evaluated. A regression-based procedure served to compute percentiles of CFWQ and its subscales. RESULTS: Four hundred twenty-one participants without psychiatric and/or neurological disorders completed the survey. We found that the Italian CFWQ included 26 items, with a good internal consistency (Cronbach's alpha = 0.897) and a six-factor structure (memory, language, processing speed, abstract thinking/behavioral control, behavioral inertia, planning ability). CFWQ score did not correlate with empathy but correlated strongly with memory scores and moderately with anxiety and depression scores. CONCLUSIONS: The Italian CFWQ showed good psychometric properties, in analogy with the original English scale. Therefore, it can be successfully employed in organizational contexts to possibly identify workers with CC and therefore with possible co-occurrent psychological, behavioral, and cognitive consequences.

The Efficacy of Cognitive Training on Neuropsychological Outcomes in Mild Cognitive Impairment: A Meta-Analysis.

Mild cognitive impairment (MCI) or mild neurocognitive disorder is an intermediate stage of cognitive impairment between normal cognitive aging and dementia. Given the absence of effective pharmacological treatments for MCI, increasing numbers of studies are attempting to understand how cognitive training (CT) could benefit MCI. This meta-analysis aims to update and assess the efficacy of CT on specific neuropsychological test performance (global cognitive functioning, short-term verbal memory, long-term verbal memory, generativity, working memory, and visuospatial abilities) in individuals diagnosed with MCI, as compared to MCI control groups. After searching electronic databases for randomized controlled trials, 31 studies were found including 2496 participants. Results showed that CT significantly improved global cognitive functioning, short-term and long-term verbal memory, generativity, working memory, and visuospatial abilities. However, no significant effects were observed for shifting, abstraction ability/concept formation, processing speed, and language. The mode of CT had a moderating effect on abstraction ability/concept formation. The findings provide specific insights into the cognitive functions influenced by CT and guide the development of tailored interventions for MCI. While CT holds promise, further research is needed to address certain cognitive deficits and assess long-term effects on dementia progression.

Early Detection of Depression in Parkinson's Disease: Psychometrics and Diagnostics of the Spanish Version of the Beck Depression Inventory.

OBJECTIVE: Depression is one of the most disabling non-motor symptoms in Parkinson's disease (PD) and requires proper diagnosis as it negatively impacts patients' and their relatives quality of life. The present study aimed to examine the psychometric and diagnostic properties of the Beck Depression Inventory-I (BDI-I) in a Spanish PD cohort. METHOD: Consecutive PD outpatients completed the Spanish version of the BDI-I and other questionnaires assessing anxiety and apathy. Patients' caregivers completed the depression/dysphoria domain of the Neuropsychiatric Inventory (NPI-D). The internal consistency, convergent and divergent validity and the factorial structure of BDI-I were evaluated, and an optimal cut-off was defined by means of the Youden index. RESULTS: The BDI-I proved to have a good internal consistency and was underpinned by a mono-component structure. Regarding construct validity, the BDI-I was substantially related to anxiety and apathy measures in PD. Furthermore, the BDI-I overall showed good accuracy with adequate sensitivity and specificity. The optimal cut-off point was defined at 10. CONCLUSIONS: We provided evidence of the psychometric and diagnostic properties of the Spanish version of the BDI-I as a screening tool for depression in Spanish speaking PD patients, suggesting its usefulness in clinical research and practice.