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Intrinsic motivation deficits are a prominent feature of schizophrenia that substantially impacts functional outcome. This study used cluster analysis of innate real-world behaviours captured during two open-field tasks to dimensionally examine heterogeneity in intrinsic motivation in schizophrenia patients (SZ) and healthy controls (HC). Wireless motion capture quantified participants’ behaviours aligning with distinct aspects of intrinsic motivation: exploratory behaviour and effortful activity in the absence of external incentive. Cluster analysis of task-derived measures identified behaviourally differentiable subgroups, which were compared across standard clinical measures of general amotivation, cognition, and community functioning. Among 45 SZ and 47 HC participants, three clusters with characteristically different behavioural phenotypes emerged: low exploration (20 SZ, 19 HC), low activity (15 SZ, 8 HC), and high exploration/activity (10 SZ, 20 HC). Low performance in either dimension corresponded with similar increased amotivation. Within-cluster discrepancies emerged for amotivation (SZ > HC) within the low exploration and high performance clusters, and for functioning (SZ

The ability to use feedback to guide optimal decision-making is essential for goal-directed behaviour. While impairments in feedback-driven decision-making have been associated with schizophrenia and depression, this has been examined primarily in the context of binary probabilistic choice paradigms. In real-world decision-making, however, individuals must make choices when there are more than two competing options that vary in the frequency and magnitude of potential rewards and losses. Thus, the current study examined win-stay/lose-shift (WSLS) behaviour on the Iowa Gambling Task (IGT) in order to evaluate the influence of immediate rewards and losses in guiding real-world decision-making in patients with schizophrenia and major depressive disorder. Fifty-one patients with schizophrenia, 43 patients with major depressive disorder, and 51 healthy controls completed the IGT, as well as a series of clinical and cognitive measures. WSLS was assessed by quantifying trial-by-trial behaviour following rewards and losses on the IGT. Multivariate analyses of variance revealed that patients with schizophrenia demonstrated intact lose-shift behaviour, but significantly reduced win-stay rates compared to healthy controls. In contrast, no WSLS impairments emerged in the depressed group. Win-stay impairments in the schizophrenia group were significantly related to deficits in motivation and cognition. Patients with schizophrenia exhibit impaired reward-driven decision-making in the context of multiple choices with concurrent rewards and losses, and this appears to be driven by a reduced propensity for advantageous win-stay behaviour. With the importance of reward learning and decision-making in generating goal-directed behaviour, these findings suggest a potential mechanism contributing to the motivation deficits seen in schizophrenia.

Background Previous studies have suggested that, despite marked functional impairments, remitted first episode patients with schizophrenia report levels of well-being that are comparable to healthy controls. The aim of the current study was to specifically evaluate self-reported happiness, life satisfaction and success in individuals with schizophrenia beyond their first-episode of psychosis, and to investigate the impact of symptoms and functioning on these subjective experiences. Methods Fifty-one schizophrenia patients and 56 matched healthy controls participated in the study. Factor scores were computed to compare happiness and life satisfaction and success (LSS) between groups. Hierarchical multiple regression analyses were conducted to investigate the predictive value of symptoms and functional impairments on patients' subjective reports of happiness and LSS. Results Schizophrenia participants endorsed lower levels of LSS compared to healthy controls, with no significant group differences in self-reported happiness. For patients with schizophrenia, motivation deficits and depressive symptoms predicted reductions in both happiness and LSS. Conclusions Patients with schizophrenia do not report significant reductions in their subjective experience of happiness, but do endorse lower levels of life satisfaction and success. Further, the absence of a robust link between poor functioning and lower happiness or LSS serves to reaffirm the notion that functional status does not dictate whether an individual with schizophrenia experiences a sense of happiness, satisfaction or success in life.

Background Intrinsic motivation (IM) deficits are a prominent feature of schizophrenia that substantially impacts functional outcome. Previous investigations have primarily assessed IM as a general construct or towards specific activities, but multifaceted examination of IM using objective and ecologically valid means has been lacking. The current study aimed to determine whether IM-driven real-world behaviours of individuals with and without schizophrenia reveal distinct behavioural phenotypes that predict differential clinical and functional profiles. Methods Forty-five stable adult outpatients with schizophrenia or schizoaffective disorder (SZ) and 47 healthy controls (HC), group-matched for age and sex, completed the study. Wireless motion capture was used to quantify participants’ behaviour (during two previously validated 15-minute open-field tasks) aligning with distinct aspects of IM: exploratory behaviour (in an unfamiliar setting that contained common and uncommon objects) and unincentivized activity engagement (under provision of explicit choice between active versus passive engagement options). Sparse k-means clustering was applied to task-derived indices of locomotion and object exploration, and activity duration, intensity, and persistence to identify behaviourally differentiable subgroups. Clusters were compared across standard clinical measures of general amotivation, cognition, and community functioning. Diagnostic group by cluster assignment interaction effects were evaluated to identify potential discrepancies in within-cluster SZ versus HC differences across clusters. Results Three clusters emerged: medium activity and low exploration (20 SZ and 19 HC), low activity and medium exploration (15 SZ and 8 HC), and high activity and exploration (10 SZ and 20 HC). Cluster assignment did not significantly predict diagnostic group (Fisher’s exact p=0.067) but indicated increased odds of diminished exploration or activity in SZ (odds ratio=2.57, p=0.047). General amotivation differed across clusters (F(2,89)=6.31, p=0.003) due to significantly elevated scores in the low exploration and low activity clusters versus the high performance cluster. Evaluation of the diagnostic group by cluster assignment interaction effect for amotivation (F(2,86)=3.12, p=0.062) revealed significantly higher scores in SZ versus HC within the low exploration and high performance clusters, but not the low activity cluster. Evaluation of the interaction effect for community functioning (F(2,86)=4.86, p=0.007) revealed significantly lower scores in SZ versus HC within all clusters, with the discrepancy increasing from high performance to low activity to low exploration. Discussion Multidimensional characterization of IM stands to provide valuable insights into motivation and functioning deficits in schizophrenia that behaviourally manifest differently across individuals. Impairment in IM-driven behaviour may be substantially detrimental particularly for individuals with schizophrenia, as SZ participants demonstrated clinically observable deficits even compared to within-cluster HC counterparts. The current lack of objective standards to measure IM underscores the benefit of behaviour-based characterization. Further, as IM has been deemed a valuable psychosocial intervention target in schizophrenia, multidimensional behavioural phenotyping may help guide personalized therapy by differentiating between IM impairments demanding amelioration versus unimpaired tendencies that may be leveraged to facilitate remediation.

BACKGROUND: Motivation deficits have been linked to poor functional outcomes in schizophrenia (SZ) and major depressive disorder (MDD) and represent an unmet therapeutic need. Recent conceptualizations of the motivation system have outlined five inter-related reward processes, whereby (1) reward responsiveness (i.e. “liking”) and (2) reward prediction (i.e. “wanting”, established through appropriate reward learning) converge to inform both (3) reward valuation and (4) effort valuation which is associated with a cost-benefit analysis, followed by (5) the development and execution of an action plan to achieve the desired outcome. The inclusion of approach motivation within the RDoC Positive Valence System further underscores its importance as a pervasive symptom that cuts across traditional diagnostic boundaries. Previous investigations, however, have typically only focused on isolated reward processes, often within single diagnostic groups. Thus, in line with emerging dimensional approaches to examining psychopathology, the present study sought to utilize a cluster-analytic approach to objectively evaluate the multiple facets of the motivation system concurrently across SZ, MDD, and healthy control (HC) participants. METHODS: The study sample consisted of 39 SZ, 38 MDD, and 39 HC participants. Participants were administered a series of assessments to evaluate symptom severity and cognitive functioning. Discrete facets of the motivation system were measured using an extensive battery of objective computerized tasks. Variables of interest were extracted from each task and entered into a principal components analysis in order to explore the factor structure of the motivation framework. Factor scores were subsequently applied to K-means cluster analysis to identify subgroups of individuals with similar motivation profiles. RESULTS: Principal components analysis revealed five distinct motivation factors: hedonic capacity, reward expectancy and learning, cost-benefit decision-making, goal-directed decision-making, and effort expenditure. K-means clustering identified two distinct subgroups of individuals based on their motivation task performance. The first cluster demonstrated impaired hedonic capacity (t(114)=-3.7, p

BACKGROUND: Motivation deficits and reduced goal-directed behaviour are prominent in schizophrenia (SZ), and significantly contribute to poor functional and treatment outcomes. One of the critical components of the multi-faceted motivation system is effort valuation, which refers to the mental processes involved in computing how much effort one is willing to exert in order to obtain a desired outcome. These effort-cost computations are typically measured using effort-based decision-making (EBDM) paradigms, where individuals must choose between performing low- or high-effort tasks for varying reward magnitudes. Rather than demonstrating an overall unwillingness to expend effort, however, studies have shown that individuals with SZ inefficiently allocate effort across different probability and reward conditions. Thus, in order to better understand the underlying computations involved in effort-based decision-making, the present study sought to model the predictors of choice behaviour in SZ and healthy control (HC) participants. METHODS: Fifty-one SZ patients and 51 demographically-matched HC participants completed the Effort Expenditure for Rewards Task (EEfRT) as a measure of EBDM. In addition, all participants underwent characterization of clinical amotivation severity and cognitive functioning using the Apathy Evaluation Scale (AES) and Brief Assessment of Cognition in Schizophrenia (BACS), respectively. Generalized Estimating Equations (GEE) were subsequently applied to the EEfRT data with a binary logistic distribution used to model the likelihood of choosing hard tasks. A number of models were tested with independent variables including reward magnitude, probability, expected value (EV), diagnostic group, AES, and BACS. RESULTS: GEE models revealed significant main effects for reward magnitude (b = .54, p < .001), probability (b = .02, p < .001), and EV (b = .46, p < .001), but no main effect of group. However, significant interaction terms were found between group and reward (b = -.33, p < .001), group and probability (b = -.01, p = .007), and group and EV (b = -.58, p = .001). While there were no AES or BACS main effects, there were significant AES x reward (b = -.02, p < .001) and AES x EV (b = -.02, p = .01) interactions, as well as BACS x reward (b = .11, p < .001), BACS x probability (b = .01, p < .001), and BACS x EV (b = .31, p < .001) interactions. DISCUSSION: While SZ and HC participants are similarly willing to exert effort in pursuit of a reward, patients with SZ are less likely to utilize important information regarding the magnitude, probability, and expected value associated with that reward in driving their effort-based decision-making. Moreover, reward magnitude and EV are less predictive of effortful choices for individuals with greater motivation and cognitive impairments, regardless of their diagnostic status. Taken together, these findings suggest a direct link between amotivation, cognition, and inefficient utilization of reward and probability information in the context of choice behaviour and effort-cost computations.

Background Although many comprehensive batteries exist to evaluate the nature and degree of cognitive impairments in patients with schizophrenia, short batteries hold promise for rapidly screening and estimating deficits in global cognition. Recently, the Brief Neurocognitive Assessment (BNA) was established and has been shown to have similar validity and utility to a more comprehensive battery of cognitive tests in evaluating global cognitive impairments in patients with schizophrenia. The present study sought to further establish the validity of the BNA by comparing it with the MATRICS Consensus Cognitive Battery (MCCB). Methods One-hundred seventy-six patients with schizophrenia and 300 healthy volunteers participated in the present study. Global cognition was evaluated using the MCCB composite score and estimated using the BNA. To examine practice effects and test–retest reliability, patients were re-assessed after 4 weeks. Results The BNA was highly correlated with global cognition as evaluated by the MCCB in both the schizophrenia ( r = 0.82) and healthy control samples ( r = 0.75). Both instruments were similarly sensitive to deficits in global cognition in patients with schizophrenia relative to healthy controls. The BNA also demonstrated high test–retest reliability in patients with schizophrenia ( r = 0.87), comparable to the level observed with the MCCB ( r = 0.91). In addition, both the BNA and MCCB showed a similar level of practice effects (both Cohen's d = 0.11), and both instruments demonstrated equivalent sensitivities to longitudinal change. Furthermore, scores from the BNA and MCCB were related to symptom severity and functional capacity to a similar degree. Conclusions The BNA provides clinicians and researchers with an efficient and reliable means by which to evaluate global neurocognitive impairments in patients with schizophrenia by allowing estimation of performance on a more comprehensive standardized battery.

Amotivation and reduced goal-directed activity engagement are prominent features of schizophrenia. Previous investigations of patients' activities have relied on accounts of daily living activities, rather than objective measures. This study used wireless motion capture to objectively evaluate activity preference when individuals are provided an explicit choice between an active versus passive engagement option. Twenty outpatients with schizophrenia and twenty matched healthy controls completed the Activity Preference Task, in which participants play a motion-based game (active) or watch a film (passive), and were administered clinical and cognitive assessments. Schizophrenia participants' duration, intensity, and persistence of active engagement were associated with apathy and community functioning. No group differences emerged from comparisons of task measures; however, exploratory cluster analysis identified a distinct subgroup of schizophrenia patients with reduced engagement and increased apathy compared to other patients and controls. The Task provides a means of quantifying activity engagement, which may be particularly valuable given the lack of objective measures for intrinsically motivated behaviours. Our initial findings suggest that schizophrenia patients as a group are equally inclined as healthy individuals towards actively engaging activities when presented an explicit choice, but such provision may be insufficient for initiation and maintenance of functional behaviours among amotivated patients.

Background: Motivation deficits have emerged as a critical determinant of functional disability in schizophrenia. Effective therapeutic strategies for motivation deficits, however, remain elusive. This has ultimately hindered our ability to promote recovery for affected individuals. To address this unmet therapeutic need, this open-label pilot study investigated a novel virtual reality-based (VR) training strategy for the treatment of motivation deficits in schizophrenia over the course of 8 weeks of training, along with concomitant effects on community functioning and brain structure and function.

Background: Anhedonia has long been associated with schizophrenia (SZ); however, the true nature of this deficit remains elusive. Given the role of hedonic capacity within the larger motivational framework, we sought to examine reward responsiveness (RR) and reward expectancy (RE) across a spectrum of motivation deficits in SZ (Study 1). Further, we sought to better understand the relationship between hedonic capacity and specific facets of the motivational system (Study 2).

Background: Evidence from probabilistic reinforcement learning tasks have revealed impaired reward-driven learning in schizophrenia. This has been examined exclusively in the context of binary probabilistic choice paradigms. In real-world decision-making, however, individuals must also make choices when there are more than 2 competing options that vary in the frequency and magnitude of potential rewards and losses. To advance our understanding of decision-making in schizophrenia, it is important to examine how patients manage choices in the face of concurrent rewards and losses—especially when the immediately rewarding choice is not necessarily the advantageous option in the long run. Thus, the current study examined Win-Stay/Lose-Shift (WSLS) behavior on the Iowa Gambling Task (IGT) in order to examine the influence of immediate rewards and losses in guiding real-world decision-making in schizophrenia.

Anhedonia has traditionally been considered a characteristic feature of schizophrenia, but the true nature of this deficit remains elusive. This study sought to investigate consummatory and anticipatory pleasure as it relates to motivation deficits. Eighty-four outpatients with schizophrenia and 81 healthy controls were administered the Temporal Experience of Pleasure Scale (TEPS), as well as a battery of clinical and cognitive assessments. Multivariate analyses of variance were used to examine the experience of pleasure as a function of diagnosis, and across levels of motivation deficits (i.e. low vs. moderate. vs. high) in schizophrenia. Hierarchical regression analyses were also conducted to evaluate the predictive value of amotivation in relation to the TEPS. There were no significant differences between schizophrenia and healthy control groups for either consummatory or anticipatory pleasure. Within the schizophrenia patients, only those with high levels of amotivation were significantly impaired in consummatory and anticipatory pleasure compared to low and moderate groups, and compared to healthy controls. Further, our results revealed that amotivation significantly predicts both consummatory and anticipatory pleasure, with no independent contribution of group. Utilizing study samples with a wide range of motivation deficits and incorporating objective paradigms may provide a more comprehensive understanding of hedonic deficits.

Background Amotivation and reduced engagement in goal-directed activities are prominent features of schizophrenia. Previous investigations of patients’ engagement in activities have largely relied on accounts of daily living activities rather than objective task-based measures. The current study used wireless motion capture in an open-field setting to evaluate activity preference when individuals are provided an explicit choice between an active engagement option versus a passive engagement option. Methods Twenty stable adult outpatients with schizophrenia and twenty matched healthy controls completed the Activity Preference Task, in which participants play a physical motion-based video game (active engagement) or watch a film (passive engagement) for fifteen minutes. No incentive was associated with either activity, and participants could engage in either activity at any time. Duration of engagement on the active option and number of switches between activity options were computed as the primary task outcome measures using objective motion data. Participants’ behaviour during active engagement was further quantified by computation of physical intensity (average hand speed) and persistence (tendency for sustained continuous engagement). Clinical assessments of positive and negative symptoms, apathy, cognition, depression, medication side-effects, motor ability, and community functioning were also administered. Results Schizophrenia participants’ duration, intensity, and persistence of active engagement were correlated with apathy (|ρ|=0.72–0.79, p

Pain is a common problem faced by Parkinson's disease (PD) patients. Despite its impact and disabling effects pain is still frequently overlooked. In this study we analyze a representative sample of peer reviewed literature for the prevalence and types of pain in PD, the impact and significance of pain in the quality of life of the PD patient and the challenges inherent in the diagnosis and management of pain in PD patients. We compared and analyzed the findings of articles indexed in the PubMed database which looked at symptoms reported by large cohorts of PD patients. These articles all reported the incidence, nature and quality of pain in these patients and described the effects of pain on quality of life and generally were cross-sectional, retrospective or case-control studies, though a major pharmacoepidemiological design study was also analyzed. Results of our analysis showed that the pain was prevalent in 59.77% of PD patients. Five different types of pain were reported by PD patients--dystonia, musculoskeletal pain, nerve/nerve root pain, primary/central pain and according to some, akathisia. Patients who reported pain symptoms were also significantly more likely to report associated depression and a decreased quality of life. Many PD patients also reported poor management of pain and lower analgesic use than would be expected. We further discuss some of the possible approaches toward the development of a treatment algorithm regarding the management of pain in PD. We conclude that pain in is an under-recognized and under treated symptom in PD patients. Effective management of pain in PD patients would significantly improve their quality of life. Our analysis is in line with current thinking that identifies PD is much more of a multisystem disease with non-motor symptoms than previously thought.

Aim While much research has been conducted towards understanding the basis of visual hallucinations in Parkinson's disease, little has focused on characterizing the content and patients' emotional experience. These factors are likely very influential on a patient's decision to seek treatment, a critical aspect of any symptom from the clinical perspective. Methods A retrospective chart analysis was performed on Parkinson's disease patients seen in a community-based Parkinson's Disease and Movement Disorder Clinic between 2005 and 2010. Results The study consisted of 334 patients with Parkinson's disease, among whom 10.5% had visual hallucinations. Hoehn and Yahr disease stage (P = 0.001), concurrent presence of dementia (P = 0.001),and sex (P = 0.031) were significant onset predictors. The most significant determinant of treatment-seeking was emotional reaction, namely whether hallucinations were bothersome (P = 0.008). However, the specific type of content during hallucinations was sometimes more influential and contradicted emotional response. Conclusion Although treatment-seeking can be predicted by how individuals feel about hallucinations, a patient's decision may not be logically consistent. We suggest that clinicians offer treatment based on patients' recollections and opinions.

Young onset Parkinson's disease patients, typically aged 21 to between 40 and 55, have symptomatology similar to regular onset patients. Despite this, we suspect that physicians take longer to diagnose young onset patients since Parkinson's disease is ruled out due to the younger age. The history prior to diagnosis of 14 young onset patients (within 21 to 45 years of age) was compared with an equivalent number of regular onset patients matched by gender, tremor presence, and Hoehn and Yahr stage. Indeed, a longer period of time was taken to diagnose younger patients with an average of additional 15 months (p

Background Despite being an important non-motor symptom of PD, pain remains largely understudied in PD patients. Experiencing symptoms of pain is highly disruptive of general functioning, as it may hinder both physical prowess and psychological well-being. Although pain is prevalent in the otherwise healthy geriatric population, its increased presence in PD, and the difficulty it poses when combined with other hallmark motor symptoms necessitates further investigation. An improved understanding of factors that aggravate pain, and methods that alleviate discomfort may provide significant insight on the basis of pain in PD. Such information may ultimately allow healthcare professionals to achieve the goal of improved PD patient management. Objective To study the associations between various factors and pain in a Parkinson's disease (PD) patient population. Methods This study investigated 121 PD patients, of which 80 reported to have pain in at least one area of the body. Exclusion criteria included patients suffering from external causes of pain, such as trauma and patients with cognitive impairment whose accounts may not have been reliable. Further inquiry determined the etiology of pain, as well as aggravating and alleviating factors. The efficacies of pharmacological or non-pharmacological therapies were assessed through additional questioning. Individuals were also asked whether their pain was unintentionally affected by other measures, such as prescribed PD medications. Results Multiple linear regression analysis with a Wald test value of 4.070 (p = 0.044) demonstrated a statistically significant relationship between the administration of analgesics in patients with high reported pain and their pain relief. However, patients who experienced moderate pain did not exhibit any statistically significant levels of pain relief with the use of analgesics (Wald = 2.097, p = 0.148). Similarly, non-pharmacological therapies, PD medicine, and comorbidities showed no statistically significant correlations with pain relief. Conclusions Physicians should be aware of the physiological and psychological factors that form major components of pain relief, and that patient education and support are critical to successful treatment programs.

Video games are now a ubiquitous form of entertainment that has occasionally attracted negative attention. Video games have also been used to test cognitive function, as therapeutic interventions for neuropsychiatric disorders, and to explore mechanisms of experience-dependent structural brain changes. Here, we review current research on video games published from January 2011 to April 2014 with a focus on studies relating to mental health, cognition, and brain imaging. Overall, there is evidence that specific types of video games can alter brain structure or improve certain aspects of cognitive functioning. Video games can also be useful as neuropsychological assessment tools. While research in this area is still at a very early stage, there are interesting results that encourage further work in this field, and hold promise for utilizing this technology as a powerful therapeutic and experimental tool.

Schizophrenia is a heterogeneous disorder characterized by numerous diverse signs and symptoms. Individuals with prominent, persistent, and idiopathic negative symptoms are thought to encompass a distinct subtype of schizophrenia. Previous work, including studies involving neuropsychological evaluations, has supported this position. The present study sought to further examine whether deficit patients are cognitively distinct from non-deficit patients with schizophrenia. A comprehensive neurocognitive battery including tests of verbal memory, vigilance, processing speed, reasoning, and working memory was administered to 657 patients with schizophrenia. Of these, 144 (22 %) patients were classified as deficit patients using a proxy identification method based on severity, persistence over time, and possible secondary sources (e.g., depression) of negative symptoms. Deficit patients with schizophrenia performed worse on all tests of cognition relative to non-deficit patients. These patients were characterized by a generalized cognitive impairment on the order of about 0.4 standard deviations below that of non-deficit patients. However, when comparing deficit patients to non-deficit patients who also present with negative symptoms, albeit not enduring or primary, no group differences in cognitive performance were found. Furthermore, a discriminant function analysis classifying patients into deficit/non-deficit groups based on cognitive scores demonstrated only 62.3 % accuracy, meaning over one-third of individuals were misclassified. The deficit subtype of schizophrenia is not markedly distinct from non-deficit schizophrenia in terms of neurocognitive performance. While deficit patients tend to have poorer performance on cognitive tests, the magnitude of this effect is relatively modest, translating to over 70 % overlap in scores between groups.

Among the constellation of symptoms that characterize schizophrenia, negative symptoms have emerged as a critical feature linked to the functional impairment experienced by affected individuals. Despite advances in our understanding of the role of negative symptoms in the illness, effective treatments for these debilitating symptoms have remained elusive. In this review we explore the contemporary conceptualization of negative symptoms in schizophrenia, including the identification of two key subdomains of diminished expression and amotivation, and clarifications around hedonic capacity. We then explore strategies for clinical assessments of negative symptoms, followed by findings using objective paradigms for evaluating discrete aspects of these negative symptoms in clinical populations and animal models, both for symptoms of diminished expression and within the multifaceted motivation system. We conclude with a consideration of current strategies for drug development for these negative symptoms, the role of heterogeneity in the clinical presentation of symptoms in schizophrenia and opportunities for personalized assessment and treatment approaches, as well as a commentary on current clinical drug trial design and the role of environmental opportunities for novel treatments to effect change and improve outcomes for affected individuals.

Background: Deficits in attention are an enduring feature of schizophrenia that deters cognitive capacity and ultimately functional outcome. Existing tasks of attention are typically abstract, with limited relevance to everyday life. We evaluated attention in a virtual factory setting, where participants act as quality inspectors to identify defective objects on moving conveyor belts. Further, to examine the neurobiological underpinnings of attention in this simulated real-world setting, we evaluated associations between task performance and structural brain connectivity using diffusion tensor imaging (DTI).

The uncertain relationship between negative symptoms, and specifically motivational deficits, with cognitive dysfunction in schizophrenia is in need of further elucidation as it pertains to the interpretation of cognitive test results. Findings to date have suggested a possible mediating role of motivational deficits on cognitive test measures, although findings from formal examinations of effort using performance validity measures have been inconsistent. The aim of this study was to examine the relationships between motivation, effort exerted during cognitive testing, and cognitive performance in schizophrenia. Sixty-nine outpatients with schizophrenia or schizoaffective disorder were evaluated for psychopathology, severity of motivational deficits, effort exerted during cognitive testing, and cognitive performance. Motivation and degree of effort exerted during cognitive testing were significantly related to cognitive performance, specifically verbal fluency, verbal and working memory, attention and processing speed, and reasoning and problem solving. Further, effort accounted for 15% of the variance in cognitive performance, and partially mediated the relationship between motivation and cognitive performance. Examining cognitive performance profiles for individuals exerting normal or reduced effort revealed significant differences in global cognition, as well as attention/processing speed and reasoning and problem solving. These findings suggest that cognitive domains may be differentially affected by impairments in motivation and effort, and highlight the importance of understanding the interplay between motivation and cognitive performance deficits, which may guide the appropriate selection of symptom targets for promoting recovery in patients.

The Heinrichs-Carpenter Quality of Life Scale (QLS) is the most extensively used real-world community functioning scale in schizophrenia research. However, the extensive time required to administer it and the inclusion of items that overlap conceptually with negative symptoms limit its use across studies. The present study examined the validity and utility of two abbreviated QLS measures against the full QLS excluding negative symptom items.The sample included 1427 patients with schizophrenia who completed the baseline visit in the CATIE study. The validity of two abbreviated QLS measures (7-item and 4-item) were examined with the full QLS, excluding the intrapsychic foundations subscale, using correlation analysis. The utility of the abbreviated measures was explored by examining associations between the functioning scales and clinical variables and longitudinal change.Both abbreviated QLS measures were highly predictive of the full QLS (both r=0.91, p0.001), with no difference in predictive value between the abridged measures. Functional status was significantly associated with symptoms and cognition. Importantly, the strength of these associations was similar between the abbreviated and full QLS. Finally, multiple regression models examining the explanatory power of amotivation/apathy in predicting functioning scores after other symptoms and neurocognition had been accounted for were essentially identical irrespective of the QLS instrument used as the dependent measure. Longitudinal change was also similar across the three scales.The 7-item abbreviated QLS is recommended as a brief measure of community functioning for individuals with schizophrenia, especially when assessment of functional outcome is not the focus.

Action tremor (AT) and resting tremor (RT) have been widely cited in many studies with Parkinson's disease (PD) patients, but studies looking at the association between the two tremor types are few and show inconsistent results. This study will look at the prevalence and association of AT and RT in a large sample of idiopathic PD patients, and will put the results into context with the literature.A retrospective chart review analysis of 332 patients with idiopathic PD was performed. Prevalence rates of particular tremor types were noted. The presence of AT was analyzed relative to the presence and severity of RT.Nearly all individuals with AT also had RT. The concurrence of the two tremor types was found to be highly significant by statistical analysis (P0.0001). The severity of RT, measured by its laterality, may also be of importance, albeit to a much smaller extent if at all. Neither presence of tremor nor type of tremor present was influenced by patient gender, age, or Hoehn and Yahr stage of PD.The results indicate that AT has extensive presence in PD. This and its seemingly close relationship to RT suggest that AT may be considered a variant of RT, particularly in PD patients. The degree of association between RT and AT needs to be further analyzed in PD, as well as in essential tremor (ET) and ET-PD.

Parkinson's disease (PD) is a neurodegenerative illness characterized by various non-motor symptoms that may contribute to disability, impaired quality of life and shortened life expectancy. The aim of present study was to determine the relative prevalence of common non-motor symptoms in various ethnic groups. A retrospective chart analysis was performed on Parkinson's disease patients where a total of 314 PD patients from six ethnic categories were examined for the occurrence of anxiety, visual hallucinations, nocturia, drooling and dementia. Our results show that anxiety in PD patients was correlated with their ethnicity classification. Interesting trends were observed with respect to nocturia and dementia symptoms and no significant differences were found between ethnic groups for visual hallucinations and drooling. Our study shows that non-motor symptoms of Parkinson's disease are prevalent across all ethnic groups, and except anxiety there may not be any impact of ethnicity on dementia, nocturia, drooling, and visual hallucinations.

Many patients with restless legs syndrome (RLS) and Parkinson's disease (PD) report having pain, however, the impact of the combination of PD and RLS on pain has not been analyzed extensively. The objective of this study was to explore the potential relationship between RLS and pain in individuals with and without PD, the prevalence of RLS in PD, the prevalence and severity of pain in PD and RLS, and how these measures are related to PD patients and controls.The study included 127 PD patients and an equal number of non-PD patients who were assessed for pain and RLS-like symptoms by using RLS diagnostic survey, RLS rating scale and Brief Pain Inventory.The results showed that 21.3% of PD patients had RLS, compared to only 4.7% in the control group, representing a highly significant difference (p0.005). The frequency of reporting pain was also significantly higher among PD patients with RLS (p0.005), but not in control group. However, the mean difference in average pain severity was not significantly different between the PD with RLS and non-PD with RLS, nor was the pain level and severity significantly correlated with RLS severity for either group.The presence of pain in PD patients may be exacerbated by RLS or in RLS patients, having PD may exacerbate pain.

While much research has been conducted towards understanding the basis of visual hallucinations in Parkinson's disease, little has focused on characterizing the content and patients' emotional experience. These factors are likely very influential on a patient's decision to seek treatment, a critical aspect of any symptom from the clinical perspective.A retrospective chart analysis was performed on Parkinson's disease patients seen in a community-based Parkinson's Disease and Movement Disorder Clinic between 2005 and 2010.The study consisted of 334 patients with Parkinson's disease, among whom 10.5% had visual hallucinations. Hoehn and Yahr disease stage (P = 0.001), concurrent presence of dementia (P = 0.001),and sex (P = 0.031) were significant onset predictors. The most significant determinant of treatment-seeking was emotional reaction, namely whether hallucinations were bothersome (P = 0.008). However, the specific type of content during hallucinations was sometimes more influential and contradicted emotional response.Although treatment-seeking can be predicted by how individuals feel about hallucinations, a patient's decision may not be logically consistent. We suggest that clinicians offer treatment based on patients' recollections and opinions.

Corticobasal degeneration is a progressive neurodegenerative disease involving the cerebral cortex and basal ganglia and leads primarily to motor symptoms and cognitive dysfunction. Unilateral arm dystonia is a common presenting symptom in many patients with corticobasal degeneration. This study attempts to determine if a relationship exists between arm dystonia in corticobasal degeneration and the handedness of the patient. A chart review of 12 right-handed patients (six males and six females) diagnosed with corticobasal degeneration seen in a Parkinson’s disease clinic was conducted. With the exception of a single individual who was afflicted in her dominant arm, all had dystonia in their left arm. The ages of the female patients were substantially lower than their male counterparts. Although the sample size of the patient population is small, the results raise an interesting question: is arm dystonia in corticobasal degeneration more commonly seen on the contralateral side of the dominant hand. Further observation is needed to establish a correlation.