The gut microbiome and cognition in Parkinson's disease: a systematic review.

BACKGROUND: The pathology underlying cognitive changes in people with Parkinson's disease (PD) is not well understood. In healthy older adults, gut microbiome composition has been associated with cognitive function. In people with PD, preliminary evidence suggests that cortical spreading of abnormal alpha-synuclein aggregates may be associated with cognitive impairment. As changes in the gut have been linked to PD onset and associated Lewy body pathology, an investigation of the gut microbiome and cognition in PD is warranted. OBJECTIVE: To synthesise existing evidence on the relationship between the gut microbiome and cognitive function in PD. METHODS: A systematic review was conducted to search for peer-reviewed articles and grey literature published to July 2021 across seven electronic databases (MEDLINE, EMBASE, PsycINFO, Scopus, Cochrane Library, ProQuest, and ProQuest Dissertations and Theses). English language articles reporting the relationship between cognition and the gut microbiome in human participants with PD were considered for inclusion. Results were qualitatively synthesised and evidence quality was assessed using the QualSyst tool for quantitative studies. RESULTS: Five cross-sectional studies reporting the association between the gut microbiome and cognition in 395 participants with PD were included. Studies provided preliminary evidence of a relationship between cognition and gut microbiota within the Bacteroidetes and Firmicutes phyla, however, associations with specific genera were inconsistent across studies. CONCLUSIONS: Some species of short-chain fatty acid-producing bacteria (e.g. acetate, butyrate, and propionate producers) appear to be reduced in participants with PD with cognitive impairment. More research with larger samples and more consistent methodology is needed to substantiate these findings.

Cognitive profile and mild cognitive impairment in people with chronic lower back pain.

A growing body of evidence suggests Chronic Lower Back Pain (CLBP) is associated with cognitive dysfunction. Little is known, however, about the extent of cognitive impairment in CLBP. The present study explored the cognitive profile of people with CLBP and sought to determine the extent of Mild Cognitive Impairment (MCI) according to the DSM-V and the Movement Disorders Society criteria for MCI. Thirty-one participants with CLBP and 27 age and gender matched healthy controls completed a full neuropsychological battery, consisting of two tasks for each of the five cognitive domains (Executive Function, Attention/Working Memory, Memory, Language, and Visuospatial). Participants with CLBP performed worse, compared to controls, on measures of Attention/Working Memory, Memory, Language, and Visuospatial performance. Cognitive performance in CLBP was also compared to equivalent normative data to determine cognitive impairment. Sixteen CLBP participants were impaired on at least one cognitive measure, with 5 participants meeting criteria for MCI. MCI was not associated with pain-related experience, or psychological health. The present study supports and extends previous findings that CLBP is associated with cognitive dysfunction and some people with CLBP meet criteria for MCI. These findings support that rehabilitation in people with CLBP requires a multidisciplinary approach.

Modified Mindfulness-Based Cognitive Therapy for Depressive Symptoms in Parkinson's Disease: a Pilot Trial.

BACKGROUND: Mindfulness-based cognitive therapy (MBCT) has evidence of efficacy in a range of populations, but few studies to date have reported on MBCT for treatment of anxious and depressive symptoms in Parkinson's disease (PD). AIMS: The aim of this study was to examine the efficacy of modified MBCT in reducing symptoms of anxiety and depression and improving quality of life in PD. METHOD: Thirty-six individuals with PD were randomly assigned to either modified MBCT or a waitlist control. Changes in symptoms of anxiety, depression and quality of life were compared at group level using generalized linear mixed models and at individual level using reliable change analysis. RESULTS: At post-treatment, there was a significant reduction in depressive symptoms for people undertaking modified MBCT at both group and individual levels compared with controls. There was no significant effect on anxiety or quality of life at the group level, although significantly more people had reliable improvement in anxiety after modified MBCT than after waitlist. Significantly more waitlist participants had reliable deterioration in symptoms of anxiety and depression than those completing modified MBCT. Most participants stayed engaged in modified MBCT, with only three drop-outs. DISCUSSION: This proof-of-concept study demonstrates the potential efficacy of modified MBCT as a treatment for depressive symptoms in Parkinson's disease and suggests further research is warranted.

Retrospective assessment of movement disorder society criteria for mild cognitive impairment in Parkinson's disease.

A Movement Disorder Society (MDS) taskforce recently proposed diagnostic criteria for Parkinson's disease with features of mild cognitive impairment (PD-MCI). This study first examined the prevalence and nature of PD-MCI in a non-demented cohort using the MDS criteria. Using the generic Monte Carlo simulation method developed by Crawford and colleagues (2007), this study then estimated the base rate of the representative population who would demonstrate PD-MCI due to chance alone. A total of 104 participants with idiopathic PD underwent extensive motor and neuropsychological testing at baseline and 2 years later. The Unified Parkinson's Disease Rating Scale (UPDRS) was used to assess motor symptoms of PD and a range of established neuropsychological tests was used to assess PD-MCI in accord with MDS criteria. In accord with MDS criteria, 38% of this cohort demonstrated PD-MCI at baseline and 48% at follow-up. Of the 36 participants in the multiple-domain PD-MCI subtype at time-1, 9 (25%) demonstrated no PD-MCI at follow up. Analysis revealed that approximately 13% of the representative population would demonstrate abnormally low scores for 2 of the 9 tests used, thereby meeting MDS criteria for PD-MCI. Clinicians and researchers need to approach a single diagnosis (i.e., based on one assessment) of PD-MCI with considerable caution.

Patterns and predictors of mental health service utilization in people with Parkinson's disease.

BACKGROUND: Comorbid psychiatric complications are a common occurrence in Parkinson's disease (PD). However, the majority of people with PD experiencing mental health problems do not receive any professional treatment. METHOD: A total of 327 Australian adults with PD completed a cross-sectional survey examining patterns of mental health service utilization and predictors of willingness to seek future mental health treatment. RESULTS: Only 8% of participants were currently engaged in mental health treatment despite elevated levels of depressive and anxiety symptoms. The lifetime service use rate was also low at 24%. Logistic regression analysis showed that, second to prior treatment experience (odds ratio [OR] = 3.28, 95% confidence interval [CI] = 1.46-7.35), having had a discussion about psychological symptoms with a primary PD neurologist was the next most important predictor and tripled the likelihood of an individual being willing to seek future treatment, (OR = 3.01, 95% CI = 1.72-5.27). CONCLUSION: This study highlights the integral role of the PD neurologist in facilitating awareness and treatment of mental health problems for individuals with PD.

A waitlist-controlled trial of group cognitive behavioural therapy for depression and anxiety in Parkinson's disease.

BACKGROUND: The aim of this study was to evaluate the efficacy of a group Cognitive Behavioural Therapy (CBT) treatment for depression and anxiety in Parkinson's disease (PD). METHODS: A waitlist-controlled trial design was used. Eighteen adults with PD and a comorbid DSM-IV-TR diagnosis of depression and/or anxiety were randomised to either Intervention (8-week group CBT treatment) or Waitlist (8-week clinical monitoring preceding treatment). The Depression, Anxiety, Stress Scale-21 (DASS-21) was the primary outcome. Assessments were completed at Time 1 (pretreatment), Time 2 (posttreatment/post-waitlist) and 1-month and 6-month follow-ups. RESULTS: At Time 2, participants who received CBT reported greater reductions in depression (M(change) = -2.45) than Waitlist participants (M(change) = .29) and this effect was large, d = 1.12, p = .011. Large secondary effects on anxiety were also observed for CBT participants, d = .89, p = .025. All treatment gains were maintained and continued to improve during the follow-up period. At 6-month follow-up, significant and large effects were observed for both depression (d = 2.07) and anxiety (d = 2.26). CONCLUSIONS: Group CBT appears to be an efficacious treatment approach for depression and anxiety in PD however further controlled trials with larger numbers of participants are required. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12610000455066).

Experiences of parents of trans young people accessing Australian health services for their child: Findings from Trans Pathways.

Background: Many trans young people seek mental health support and gender-affirming medical interventions including puberty suppression, gender-affirming hormones and/or surgeries. Trans young people and their parents face multiple barriers in accessing gender-affirming care and mental health support, however little is known about the parent perspective on accessing services for their trans child. Aims: This study aimed to understand the experiences of parents accessing medical and mental health services with and for their trans children within Australia. Methods: Using data from Trans Pathways, a large mixed-methods cross-sectional study, we examined the experiences of parents (N = 194) in Australia accessing primary care, psychiatry, therapy/counseling, mental health inpatient, and gender-affirming medical services with/for their trans children (aged 25 years or younger). Qualitative data on service experiences were thematically analyzed. Quantitative analyses included frequency of access to services, wait times, service satisfaction, and mental health diagnoses of the parents' trans child. Results: Services were mostly first accessed when the young person was between 12 and 17 years of age, with primary care physicians being the most accessed service. Parents reported that some practitioners were respectful and knowledgeable about gender-affirming care, and others lacked experience in trans health. Across all services, common barriers included long wait times, complicated pathways to navigate to access support, as well as systemic barriers such as sparsity of gender speciality services. Across services, parents reported feeling as though they do not have the necessary tools to best support their child in their gender affirmation. Discussion: This study highlights the crucial need for systemic changes in the processes of accessing gender-affirming care and mental health support to enable access to appropriate and timely care. These findings also indicate the importance of improving individual practitioner knowledge around trans health, to enhance the support provided to trans young people and their parents.

Anodal-TDCS over Left-DLPFC Modulates Motor Cortex Excitability in Chronic Lower Back Pain.

Chronic pain is associated with abnormal cortical excitability and increased pain intensity. Research investigating the potential for transcranial direct current stimulation (tDCS) to modulate motor cortex excitability and reduce pain in individuals with chronic lower back pain (CLBP) yield mixed results. The present randomised, placebo-controlled study examined the impact of anodal-tDCS over left-dorsolateral prefrontal cortex (left-DLPFC) on motor cortex excitability and pain in those with CLBP. Nineteen participants with CLBP (Mage = 53.16 years, SDage = 14.80 years) received 20-min of sham or anodal tDCS, twice weekly, for 4 weeks. Short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were assessed using paired-pulse Transcranial Magnetic Stimulation prior to and immediately following the tDCS intervention. Linear Mixed Models revealed no significant effect of tDCS group or time, on SICI or ICF. The interactions between tDCS group and time on SICI and ICF only approached significance. Bayesian analyses revealed the anodal-tDCS group demonstrated higher ICF and SICI following the intervention compared to the sham-tDCS group. The anodal-tDCS group also demonstrated a reduction in pain intensity and self-reported disability compared to the sham-tDCS group. These findings provide preliminary support for anodal-tDCS over left-DLPFC to modulate cortical excitability and reduce pain in CLBP.

Measuring General Expectations of Advanced Stage Treatment Outcomes in Parkinson's Disease.

BACKGROUND: Recent research suggests that a significant number of those who receive advanced treatments for Parkinson's disease (PD) do not report improvements for some symptoms, which may relate to their pre-treatment expectations. It is important that expectations of treatment are measured and discussed prior to advanced treatment. OBJECTIVE: The primary aim of this study was to develop a measure of treatment expectations of two advanced-stage treatments in PD, deep brain stimulation (DBS), and Levodopa/Carbidopa Intestinal Gel (LCIG). A secondary aim was to explore potential predictors of treatment expectations. METHODS: The questionnaire-based measure was developed by researchers in conjunction with a highly experienced clinician, and evaluated treatment expectations in 189 people aged 46-91 years (M = 71.35, SD = 8.73; 61% male) with idiopathic PD. RESULTS: The overall measure demonstrated excellent internal consistency (α= 0.96). Exploratory factor analysis suggested the scale was unidimensional for both DBS and LCIG. Participant expectations of the two treatments differed significantly, with expectations being higher for DBS. Perceived symptom severity was the strongest predictor of treatment expectations. CONCLUSION: This scale has potential to inform clinicians about client expectations prior to advanced stage therapy for PD, with a view to the management of these expectations. Further evaluation of the scale is required across different treatment contexts.

Cognitive Reserve, Executive Function, and Memory in Parkinson's Disease.

Cognitive impairment is acknowledged as a feature of Parkinson's disease (PD), and the most common cognitive declines are in executive function (EF) and memory. Cognitive reserve (CR) may offer some protection against cognitive dysfunction in PD. The present study used two proxies of CR (years of education, premorbid IQ) to examine the relationship between CR and (i) EF (ii) memory in a large PD sample (n = 334). Two aspects of EF were examined, including verbal fluency and planning skills. Two aspects of verbal memory were examined, including immediate recall and delayed recall. For EF, both CR proxies significantly predicted verbal fluency, but only years of education predicted planning skills. Years of education significantly predicted immediate recall, but premorbid IQ did not. Neither CR proxy predicted delayed recall. These findings suggest that CR, in particular years of education, may contribute to EF and memory function in those with PD. A key finding of this study is the varying contribution of CR proxies to different aspects of the same cognitive domain. The findings indicate that using only one proxy has the potential to be misleading and suggest that when testing the relationship between CR and cognition, studies should include tasks that measure different aspects of the cognitive domain(s) of interest.

Hearing Loss and Depression in Older Adults: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: Studies reporting an association between hearing loss and depression in older adults are conflicting and warrant a systematic review and meta-analysis of the evidence. RESEARCH DESIGN AND METHODS: A search of academic databases (e.g., MEDLINE) and gray literature (e.g., OpenGrey) identified relevant articles published up to July 17, 2018. Cross-sectional or cohort designs were included. Outcome effects were computed as odds ratios (ORs) and pooled using random-effects meta-analysis (PROSPERO: CRD42018084494). RESULTS: A total of 147,148 participants from 35 studies met inclusion criteria. Twenty-four studies were cross-sectional and 11 were cohort designs. Overall, hearing loss was associated with statistically significantly greater odds of depression in older adults (OR = 1.47, 95% confidence interval [CI] = 1.31-1.65). When studies were stratified by design, hearing loss was associated with greater odds of depression in cross-sectional studies (OR = 1.54, 95% CI = 1.31-1.80) and cohort studies (OR = 1.39, 95% CI = 1.16 - 1.67), and there was no difference between cross-sectional or cohort effect estimates (Q = 0.64, p = .42). There was no effect of moderator variables (i.e., hearing aid use) on the association between hearing loss and depression, but these findings must be interpreted with caution. There was no presence of publication bias but certainty in the estimation of the overall effect was classified as "low." DISCUSSION AND IMPLICATIONS: Older adults may experience increased odds of depression associated with hearing loss, and this association may not be influenced by study or participant characteristics.

The role of early fine and gross motor development on later motor and cognitive ability.

The aim of this study was to determine whether information obtained from measures of motor performance taken from birth to 4 years of age predicted motor and cognitive performance of children once they reached school age. Participants included 33 children aged from 6 years to 11 years and 6 months who had been assessed at ages 4 months to 4 years using the ages and stages questionnaires (ASQ: [Squires, J. K., Potter, L., & Bricker, D. (1995). The ages and stages questionnaire users guide. Baltimore: Brookes]). These scores were used to obtain trajectory information consisting of the age of asymptote, maximum or minimum score, and the variance of ASQ scores. At school age, both motor and cognitive ability were assessed using the McCarron Assessment of Neuromuscular Development (MAND: [McCarron, L. (1997). McCarron assessment of neuromuscular development: Fine and gross motor abilities (revised ed.). Dallas, TX: Common Market Press.]), and the Wechsler Intelligence Scale for Children-Version IV (WISC-IV: [Wechsler, D. (2004). WISC-IV integrated technical and interpretive manual. San Antonio, Texas: Harcourt Assessment]). In contrast to previous research, results demonstrated that, although socio-economic status (SES) predicted fine motor performance and three of four cognitive domains at school age, gestational age was not a significant predictor of later development. This may have been due to the low-risk nature of the sample. After controlling for SES, fine motor trajectory information did not account for a significant proportion of the variance in school aged fine motor performance or cognitive performance. The ASQ gross motor trajectory set of predictors accounted for a significant proportion of the variance for cognitive performance once SES was controlled for. Further analysis showed a significant predictive relationship for gross motor trajectory information and the subtests of working memory and processing speed. These results provide evidence for detecting children at risk of developmental delays or disorders with a parent report questionnaire prior to school age. The findings also add to recent investigations into the relationship between early motor development and later cognitive function, and support the need for ongoing research into a potential etiological relationship.

Cognitive Training and Transcranial Direct Current Stimulation for Mild Cognitive Impairment in Parkinson's Disease: A Randomized Controlled Trial.

This study examined whether standard cognitive training, tailored cognitive training, transcranial direct current stimulation (tDCS), standard cognitive training + tDCS, or tailored cognitive training + tDCS improved cognitive function and functional outcomes in participants with PD and mild cognitive impairment (PD-MCI). Forty-two participants with PD-MCI were randomized to one of six groups: (1) standard cognitive training, (2) tailored cognitive training, (3) tDCS, (4) standard cognitive training + tDCS, (5) tailored cognitive training + tDCS, or (6) a control group. Interventions lasted 4 weeks, with cognitive and functional outcomes measured at baseline, post-intervention, and follow-up. The trial was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR: 12614001039673). While controlling for moderator variables, Generalized Linear Mixed Models (GLMMs) showed that when compared to the control group, the intervention groups demonstrated variable statistically significant improvements across executive function, attention/working memory, memory, language, activities of daily living (ADL), and quality of life (QOL; Hedge's g range = 0.01 to 1.75). More outcomes improved for the groups that received standard or tailored cognitive training combined with tDCS. Participants with PD-MCI receiving cognitive training (standard or tailored) or tDCS demonstrated significant improvements on cognitive and functional outcomes, and combining these interventions provided greater therapeutic effects.

Beyond factor analysis: Multidimensionality and the Parkinson's Disease Sleep Scale-Revised.

Many studies have sought to describe the relationship between sleep disturbance and cognition in Parkinson's disease (PD). The Parkinson's Disease Sleep Scale (PDSS) and its variants (the Parkinson's disease Sleep Scale-Revised; PDSS-R, and the Parkinson's Disease Sleep Scale-2; PDSS-2) quantify a range of symptoms impacting sleep in only 15 items. However, data from these scales may be problematic as included items have considerable conceptual breadth, and there may be overlap in the constructs assessed. Multidimensional measurement models, accounting for the tendency for items to measure multiple constructs, may be useful more accurately to model variance than traditional confirmatory factor analysis. In the present study, we tested the hypothesis that a multidimensional model (a bifactor model) is more appropriate than traditional factor analysis for data generated by these types of scales, using data collected using the PDSS-R as an exemplar. 166 participants diagnosed with idiopathic PD participated in this study. Using PDSS-R data, we compared three models: a unidimensional model; a 3-factor model consisting of sub-factors measuring insomnia, motor symptoms and obstructive sleep apnoea (OSA) and REM sleep behaviour disorder (RBD) symptoms; and, a confirmatory bifactor model with both a general factor and the same three sub-factors. Only the confirmatory bifactor model achieved satisfactory model fit, suggesting that PDSS-R data are multidimensional. There were differential associations between factor scores and patient characteristics, suggesting that some PDSS-R items, but not others, are influenced by mood and personality in addition to sleep symptoms. Multidimensional measurement models may also be a helpful tool in the PDSS and the PDSS-2 scales and may improve the sensitivity of these instruments.

Factor Structure of the Ways of Coping Questionnaire in Parkinson's Disease.

The Ways of Coping Questionnaire (WCQ) is used extensively in health research, but the measurement properties and suitability of the WCQ for people with Parkinson's disease (PD) have not been psychometrically assessed. If the WCQ does not align with its original 8-factor structure in a PD population, the use of the WCQ subscales may not be appropriate. The present study used confirmatory factor analysis (CFA), exploratory factor analysis (EFA), and multiple-group EFA to determine the ideal factor structure of the WCQ in a PD sample. The original 8 factors of the WCQ were not reproduced. EFA revealed a 6-factor structure, including Distancing, Faith, Avoidance, Seeking Social Support, Planful Problem Solving, and Confrontive coping. As motor symptom severity may impact coping, the stability of the 6-factor structure was examined across motor symptom severity (mild and moderate), remaining consistent. Higher levels of overall motor severity were associated with increased use of faith and avoidance style coping. These findings suggest that the 6-factor structure of the WCQ may be more appropriate for assessing coping styles in PD.

Cognitive Training and Noninvasive Brain Stimulation for Cognition in Parkinson's Disease: A Meta-analysis.

BACKGROUND: Many people with Parkinson's disease (PD) experience cognitive decline. It is not known whether cognitive training or noninvasive brain stimulation are effective at alleviating cognitive deficits in PD. OBJECTIVE: To examine cognitive training and non-invasive brain stimulation interventions for cognition in PD. METHODS: An extensive search was conducted of published and unpublished studies in online databases. Studies were selected if they were controlled trials examining standard (not individualized) or tailored (individualized) cognitive training, repetitive transcranial magnetic stimulation (rTMS), or transcranial direct current stimulation (tDCS) in PD, with outcomes measured by standardized neuropsychological tests. RESULTS: Fourteen controlled trials met inclusion criteria. For executive function, the pooled effect size (Hedges' g) for cognitive training (standard and tailored combined) was small ( g = 0.42) but statistically significant (95% CI 0.15-0.68). The pooled effect for standard cognitive training (alone) was medium ( g = 0.51) and significant (95% CI 0.16-0.85). For attention/working memory, small pooled effect sizes were found when combining standard and tailored cognitive training ( g = 0.23; 95% CI 0.02-0.44) and for standard cognitive training alone ( g = 0.29; 95% CI 0.04-0.53), both significant. For memory, small but significant pooled effect sizes were also found when combining standard and tailored cognitive training and for standard cognitive training alone. CONCLUSIONS: The results suggest that standard and tailored cognitive training may improve executive function, attention/working memory, and memory in PD. Future studies must adopt randomized controlled trial designs to explore the therapeutic potential of these interventions.

The relationship between executive function and fine motor control in young and older adults.

The present study examined the relationship between executive function (EF) and fine motor control in young and older healthy adults. Participants completed 3 measures of executive function; a spatial working memory (SWM) task, the Stockings of Cambridge task (planning), and the Intra-Dimensional Extra-Dimensional Set-Shift task (set-shifting). Fine motor control was assessed using 3 subtests of the Purdue Pegboard (unimanual, bimanual, sequencing). For the younger adults, there were no significant correlations between measures of EF and fine motor control. For the older adults, all EFs significantly correlated with all measures of fine motor control. Three separate regressions examined whether planning, SWM and set-shifting independently predicted unimanual, bimanual, and sequencing scores for the older adults. Planning was the primary predictor of performance on all three Purdue subtests. A multiple-groups mediation model examined whether planning predicted fine motor control scores independent of participants' age, suggesting that preservation of planning ability may support fine motor control in older adults. Planning remained a significant predictor of unimanual performance in the older age group, but not bimanual or sequencing performance. The findings are discussed in terms of compensation theory, whereby planning is a key compensatory resource for fine motor control in older adults.

Prevalence and Subtypes of Mild Cognitive Impairment in Parkinson's Disease.

The current study examined the prevalence and subtypes of Mild Cognitive Impairment (MCI) in an Australian sample of people with Parkinson's Disease (PD). Seventy participants with PD completed neuropsychological assessments of their cognitive performance, using MDS Task Force Level II diagnostic criteria for PD-MCI. A cut-off score of less than one standard deviation (SD) below normative data determined impaired performance on a neuropsychological test. Of 70 participants, 45 (64%) met Level II diagnostic criteria for PD-MCI. Among those with PD-MCI, 42 (93%) were identified as having multiple domain impairment (28 as amnestic multiple domain and 14 as nonamnestic multiple domain). Single domain impairment was less frequent (2 amnestic/1 nonamnestic). Significant differences were found between the PD-MCI and Normal Cognition groups, across all cognitive domains. Multiple domain cognitive impairment was more frequent than single domain impairment in an Australian sample of people with PD. However, PD-MCI is heterogeneous and current prevalence and subtyping statistics may be an artifact of variable application methods of the criteria (e.g., cut off scores and number of tests). Future longitudinal studies refining the criteria will assist with subtyping the progression of PD-MCI, while identifying individuals who may benefit from pharmacological and nonpharmacological interventions.

Psychological Literacy Weakly Differentiates Students by Discipline and Year of Enrolment.

Psychological literacy, a construct developed to reflect the types of skills graduates of a psychology degree should possess and be capable of demonstrating, has recently been scrutinized in terms of its measurement adequacy. The recent development of a multi-item measure encompassing the facets of psychological literacy has provided the potential for improved validity in measuring the construct. We investigated the known-groups validity of this multi-item measure of psychological literacy to examine whether psychological literacy could predict (a) students' course of enrolment and (b) students' year of enrolment. Five hundred and fifteen undergraduate psychology students, 87 psychology/human resource management students, and 83 speech pathology students provided data. In the first year cohort, the reflective processes (RPs) factor significantly predicted psychology and psychology/human resource management course enrolment, although no facets significantly differentiated between psychology and speech pathology enrolment. Within the second year cohort, generic graduate attributes (GGAs) and RPs differentiated psychology and speech pathology course enrolment. GGAs differentiated first-year and second-year psychology students, with second-year students more likely to have higher scores on this factor. Due to weak support for known-groups validity, further measurement refinements are recommended to improve the construct's utility.

Motor Subtype as a Predictor of Future Working Memory Performance in Idiopathic Parkinson's Disease.

Parkinson's disease is a progressive neurodegenerative disorder associated with reduced spatial and verbal working memory ability. There are two established motor subtypes of PD, tremor dominant (TD) and postural instability and gait difficulty (PIGD). This study used structural equation modelling to explore the longitudinal relationship between the two subtypes and working memory assessed at a 2-year follow-up. The study comprised 84 males and 30 females (N = 114), aged between 39 and 85 (M = 64.82, SD = 9.23) with confirmed PD. There was no significant relationship between motor subtype at Time 1 and working memory at Time 2. Postural symptom severity at Time 1 predicted Time 2 spatial working memory for the PIGD subtype (p = .011) but not the TD subtype. Tremor symptoms were not associated with Time 2 working memory in either subtype. Predictive significance of Time 1 postural symptoms only in the PIGD subtype suggests an interaction between symptom dominance (subtype) and symptom severity that future subtyping should consider. This study demonstrates a predictive relationship between postural difficulties and working memory performance assessed at a 2-year follow-up. Establishing physical symptoms as predictors of cognitive change could have significant clinical importance.