Alcohol milestones and internalizing, externalizing, and executive function: longitudinal and polygenic score associations.

BACKGROUND: Although the link between alcohol involvement and behavioral phenotypes (e.g. impulsivity, negative affect, executive function [EF]) is well-established, the directionality of these associations, specificity to stages of alcohol involvement, and extent of shared genetic liability remain unclear. We estimate longitudinal associations between transitions among alcohol milestones, behavioral phenotypes, and indices of genetic risk. METHODS: Data came from the Collaborative Study on the Genetics of Alcoholism (n = 3681; ages 11-36). Alcohol transitions (first: drink, intoxication, alcohol use disorder [AUD] symptom, AUD diagnosis), internalizing, and externalizing phenotypes came from the Semi-Structured Assessment for the Genetics of Alcoholism. EF was measured with the Tower of London and Visual Span Tasks. Polygenic scores (PGS) were computed for alcohol-related and behavioral phenotypes. Cox models estimated associations among PGS, behavior, and alcohol milestones. RESULTS: Externalizing phenotypes (e.g. conduct disorder symptoms) were associated with future initiation and drinking problems (hazard ratio (HR)⩾1.16). Internalizing (e.g. social anxiety) was associated with hazards for progression from first drink to severe AUD (HR⩾1.55). Initiation and AUD were associated with increased hazards for later depressive symptoms and suicidal ideation (HR⩾1.38), and initiation was associated with increased hazards for future conduct symptoms (HR = 1.60). EF was not associated with alcohol transitions. Drinks per week PGS was linked with increased hazards for alcohol transitions (HR⩾1.06). Problematic alcohol use PGS increased hazards for suicidal ideation (HR = 1.20). CONCLUSIONS: Behavioral markers of addiction vulnerability precede and follow alcohol transitions, highlighting dynamic, bidirectional relationships between behavior and emerging addiction.

Antecedents of mind wandering states in healthy aging and mild cognitive impairment.

OBJECTIVE: Mind wandering refers to periods of internally directed attention and comprises up to 30% or more of our waking thoughts. Frequent mind wandering can be detrimental to ongoing task performance. We aim to determine whether rates of mind wandering change in healthy aging and mild cognitive impairment and how differences in mind wandering contribute to differences in attention and working memory. METHOD: We administered a standard behavioral task, the Sustained Attention to Response Test, to measure mind wandering in healthy younger adults (N = 66), healthy older adults (N = 51), and adults with cognitive impairment (N = 38), that was completed daily for 3 weeks. The N-back test was also administered at a reduced frequency as a measure of working memory performance. RESULTS: Generally speaking, averaged across 3 weeks of testing, relative to healthy older adults, mind wandering was higher in younger adults and in cognitive impairment, although the specific patterns varied across mind wandering states. Multiple states of mind wandering also predicted working memory performance; however, reaction time variability tended to be the best predictor based on model comparisons. Each state was also modestly associated with different dispositional factors including mood and Agreeableness. CONCLUSIONS: Patterns of mind wandering change across healthy aging and cognitive impairment and are related to individual differences in multiple dispositional factors and also working memory performance. These results suggest that different states of mind wandering should be measured and accounted for when modeling cognitive change in healthy and pathological aging. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Relationships between hourly cognitive variability and risk of Alzheimer's disease revealed with mixed-effects location scale models.

OBJECTIVE: Observational studies on aging and Alzheimer's disease (AD) typically focus on mean-level changes in cognitive performance over relatively long periods of time (years or decades). Additionally, some studies have examined how trial-level fluctuations in speeded reaction time are related to both age and AD. The aim of the current project was to describe patterns of variability across repeated days of testing as a function of AD risk in cognitively normal older adults. METHOD: The current project examined the performance of the Ambulatory Research in Cognition (ARC) smartphone application, a high-frequency remote cognitive assessment paradigm, that administers brief tests of episodic memory, spatial working memory, and processing speed. Bayesian mixed-effects location scale models were used to explore differences in mean cognitive performance and intraindividual variability across 28 repeated sessions over a 1-week assessment interval as function of age and genetic risk of AD, specifically the presence of at least one apolipoprotein E (APOE) ε4 allele. RESULTS: Mean performance on processing speed and working memory was negatively related to age and APOE status. More importantly, e4 carriers exhibited increased session-level variability on a test of processing speed compared to noncarriers. Age and education did not consistently relate to cognitive variability, contrary to expectations. CONCLUSION: Preclinical AD risk, defined as possessing at least one APOE ε4 allele, is not only associated with mean-level performance differences, but also with increases in variability across repeated testing occasions particularly on a test of processing speed. Thus, cognitive variability may serve as an additional and important indicator of AD risk. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Behavioral and psychiatric correlates of brain responses to social feedback.

Maladaptive responses to peer acceptance and rejection arise in numerous psychiatric disorders in adolescence; yet, homogeneity and heterogeneity across disorders suggest common and unique mechanisms of impaired social function. We tested the hypothesis that social feedback is processed similarly to other forms of feedback (e.g., monetary) by examining the correspondence between the brain's response to social acceptance and rejection and behavioral performance on a separate reward and loss task. We also examined the relationship between these brain responses and depression and social anxiety severity. The sample consisted of one hundred and thirteen 16-21-year olds who received virtual peer acceptance/rejection feedback in an event-related potential (ERP) task. We used temporospatial principal component analysis and identified a component consistent with the reward positivity (RewP) or feedback negativity (FN). RewP to social acceptance was not significantly related to reward bias or the FN to social rejection related to loss avoidance. The relationship between RewP and depression severity, while nonsignificant, was of a similar magnitude to prior studies. Exploratory analyses yielded a significant relationship between lower socioeconomic status (SES) and blunted RewP and between lower SES and heightened loss avoidance and blunted reward bias. These findings build on prior work to improve our understanding of the function of the brain's response to social feedback, while also suggesting a pathway for further study, whereby poverty leads to depression via social and reward learning mechanisms.

Do changes in personality predict life outcomes?

The Big Five personality traits predict many important life outcomes. These traits, although relatively stable, are also open to change across time. However, whether these changes likewise predict a wide range of life outcomes has yet to be rigorously tested. This has implications for the types of processes linking trait levels and changes with future outcomes: distal, cumulative processes versus more immediate, proximal processes, respectively. The present study used seven longitudinal data sets (N = 81,980) to comprehensively examine the unique relationship that changes in the Big Five traits have with static levels and changes in numerous outcomes in the domains of health, education, career, finance, relationships, and civic engagement. Meta-analytic estimates were calculated and study-level variables were examined as potential moderators of these pooled effects. Results indicated that changes in personality traits are sometimes prospectively related to static outcomes-such as health status, degree attainment, unemployment, and volunteering-above and beyond associations due to static trait levels. Moreover, changes in personality more frequently predicted changes in these outcomes, with associations for new outcomes emerging as well (e.g., marriage, divorce). Across all meta-analytic models, the magnitude of effects for changes in traits was never larger than that of static levels and there were fewer change associations. Study-level moderators (e.g., average age, number of Big Five waves, internal consistency estimates) were rarely associated with effects. Our study suggests personality change can play a valuable role in one's development and highlights that both cumulative and proximal processes matter for some trait-outcome associations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Are some people more consistent? Examining the stability and underlying processes of personality profile consistency.

Personality traits are relatively consistent across time, as indicated by test-retest correlations. However, ipsative consistency approaches suggest there are individual differences in this consistency. Despite this, it is unknown whether these differences are due to person-level characteristics (i.e., some people are just more consistent) or exogenous forces (i.e., lack of consistency is due to environmental changes). Moreover, it is unclear whether the processes promoting long-term consistency are the same across people. We examine these two questions using item-level profile correlations across four to nine waves of data with four data sets (N = 21,616) with multilevel asymptotic growth models. Results indicated that there were, on average, high levels of profile consistency. However, there were notable individual differences in initial profile correlation values as well as in changes in levels of consistency across time, indicating that some people are more stably consistent than others. Moreover, the directions of people's trajectories across increasing time intervals suggest that the mechanisms responsible for reinforcing personality consistency vary across people. These effects were typically moderated by age at 30 years old, maturity-related traits, and education level. Overall, findings indicate some people are more consistent than others, such that this stable level of (in)consistency is a dispositional factor. Additionally, individual differences in profile consistency are shaped by different levels of three processes. On average, stochastic factors are not impactful for most individuals, and transactional processes have an important role in increasing consistency for a sizable amount of people-nuances not previously revealed when focusing on rank-order stability. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The associations between life events and person-centered personality consistency.

OBJECTIVE: Few environments reliably influence mean-level and rank-order changes in personality-perhaps because personality development needs to be examined through an individualized, person-centered lens. METHODS: The current study used Bayesian multilevel linear models to examine the association between 16 life events and changes in person-centered, Big Five personality consistency across 4 to 10 waves of data using four datasets (N = 24,491). RESULTS: Selection effects were found for events such as marriage, (un)employment, retirement, and volunteering, whereas between-person effects for slopes were found for events such as beginning formal education, employment, and retirement. Within-person changes were often small and emerged inconsistently across datasets but, when present, were brief and negative in direction, suggesting life events can serve as a short-term disruption to the personality system. However, there were many individual differences around event-related trajectories. CONCLUSION: Our results highlight that the effects of life events depend on how personality and its changes are quantified-with these findings underscoring the utility of a person-centered approach as it can capture the full range of these idiosyncrasies. Overall, these findings suggest that life events are associated with a range of idiosyncratic effects and can serve as a short-term, destabilizing shock to one's personality system.

Working memory capacity preferentially enhances implementation of proactive control.

Previous research has linked working memory capacity (WMC) with enhanced proactive control. However, it remains unclear the extent to which this relationship reflects the influence of WMC on the tendency to engage proactive control, or rather, the ability to implement it. The current study sought to clarify this ambiguity by leveraging the Dual Mechanisms of Cognitive Control (DMCC) version of the AX-CPT task, in which the mode of cognitive control is experimentally manipulated across distinct testing sessions. To adjudicate between competing hypotheses, Bayesian mixed modeling was used to conduct sequential analyses involving two separate data sets. Posterior parameter estimates obtained from the initial analysis were entered as informed priors during the replication analysis to evaluate the influence of new data on previous estimates. Results yielded strong evidence demonstrating that the influence of WMC on proactive control is most robust under experimentally controlled conditions, during which use of proactive control is standardized across participants via explicit training and instruction. Critically, the observed pattern of findings suggests that the relationship between WMC and proactive control may be better characterized as individual differences in the ability to implement proactive control, rather than a more generalized tendency to engage it. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Personalized Prediction of Behaviors and Experiences: An Idiographic Person-Situation Test.

A longstanding goal of psychology is to predict the things that people do and feel, but tools to accurately predict future behaviors and experiences remain elusive. In the present study, we used intensive longitudinal data (N = 104 college-age adults at a midwestern university; total assessments = 5,971) and three machine-learning approaches to investigate the degree to which three future behaviors and experiences-loneliness, procrastination, and studying-could be predicted from past psychological (i.e., personality and affective states), situational (i.e., objective situations and psychological situation cues), and time (i.e., trends, diurnal cycles, time of day, and day of the week) phenomena from an idiographic, person-specific perspective. Rather than pitting persons against situations, such an approach allows psychological phenomena, situations, and time to jointly predict future behaviors and experiences. We found (a) a striking degree of prediction accuracy across participants, (b) that a majority of participants' future behaviors are predicted by both person and situation features, and (c) that the most important features vary greatly across people.

Social motivation in infancy is associated with familial recurrence of ASD.

Pre-diagnostic deficits in social motivation are hypothesized to contribute to autism spectrum disorder (ASD), a heritable neurodevelopmental condition. We evaluated psychometric properties of a social motivation index (SMI) using parent-report item-level data from 597 participants in a prospective cohort of infant siblings at high and low familial risk for ASD. We tested whether lower SMI scores at 6, 12, and 24 months were associated with a 24-month ASD diagnosis and whether social motivation's course differed relative to familial ASD liability. The SMI displayed good internal consistency and temporal stability. Children diagnosed with ASD displayed lower mean SMI T-scores at all ages and a decrease in mean T-scores across age. Lower group-level 6-month scores corresponded with higher familial ASD liability. Among high-risk infants, strong decline in SMI T-scores was associated with 10-fold odds of diagnosis. Infant social motivation is quantifiable by parental report, differentiates children with versus without later ASD by age 6 months, and tracks with familial ASD liability, consistent with a diagnostic and susceptibility marker of ASD. Early decrements and decline in social motivation indicate increased likelihood of ASD, highlighting social motivation's importance to risk assessment and clarification of the ontogeny of ASD.

Childhood temperament and adulthood personality differentially predict life outcomes.

Debate has long surrounded whether temperament and personality are distinct sets of individual differences or are rather two sides of the same coin. To the extent that there are differences, it could indicate important developmental insights concerning the mechanisms responsible for linking traits with outcomes. One way to test this is to examine the joint and incremental predictive validity of temperament and personality in the same individuals across time. Using a longitudinal sample spanning 3 decades starting at infancy and followed up to 37 years old (N = 7081), we ran a series of Bayesian generalized linear models with measures of childhood temperament and adult-based personality to predict outcomes in several life domains. Results indicated that while each set of individual differences were often related to the same outcomes, there were instances in which temperament provided incremental validity above adult personality, ranging from 2 to 10% additional variance explained. Personality in childhood explained the most variance for outcomes such as cognitive ability and educational attainment whereas personality performed best for outcomes such as health status, substance use, and most internalizing outcomes. These findings indicate childhood and adulthood assessments of personality are not redundant and that a lifespan approach is needed to understand fully understand life outcomes.

Proteinopathy and Longitudinal Cognitive Decline in Parkinson Disease.

BACKGROUND AND OBJECTIVES: People with Parkinson disease (PD) commonly experience cognitive decline, which may relate to increased α-synuclein, tau, and ß-amyloid accumulation. This study examines whether the different proteins predict longitudinal cognitive decline in PD. METHODS: All participants (PD n = 152, controls n = 52) were part of a longitudinal study and completed a lumbar puncture for CSF protein analysis (α-synuclein, total tau [tau], and ß-amyloid42 [ß-amyloid]), a ß-amyloid PET scan, and/or provided a blood sample for APOE genotype (ε4+, ε4-), which is a risk factor for ß-amyloid accumulation. Participants also had comprehensive, longitudinal clinical assessments of overall cognitive function and dementia status, as well as cognitive testing of attention, language, memory, and visuospatial and executive function. We used hierarchical linear growth models to examine whether the different protein metrics predict cognitive change and multivariate Cox proportional hazard models to predict time to dementia conversion. Akaike information criterion was used to compare models for best fit. RESULTS: Baseline measures of CSF ß-amyloid predicted decline for memory (p = 0.04) and overall cognitive function (p = 0.01). APOE genotypes showed a significant group (ε4+, ε4-) effect such that ε4+ individuals declined faster than ε4- individuals in visuospatial function (p = 0.03). Baseline ß-amyloid PET significantly predicted decline in all cognitive measures (all p ≤ 0.004). Neither baseline CSF α-synuclein nor tau predicted cognitive decline. All 3 ß-amyloid--related metrics (CSF, PET, APOE) also predicted time to dementia. Models with ß-amyloid PET as a predictor fit the data the best. DISCUSSION: Presence or risk of ß-amyloid accumulation consistently predicted cognitive decline and time to dementia in PD. This suggests that ß-amyloid has high potential as a prognostic indicator and biomarker for cognitive changes in PD.

Prospective self- and informant-personality associations with inflammation, health behaviors, and health indicators.

OBJECTIVE: Personality influences many aspects of the health process. It is unclear to what extent self- and informant-reports of the Big Five offer incremental validity for the prediction of inflammatory biomarkers and whether inflammation provides a unique pathway between personality and indicators of physical health, independent of health behaviors. METHOD: Using data from older adults (N = 1,630) enrolled in the St. Louis Personality and Aging Network study, we tested whether self- and informant-reported Big Five traits show unique associations with inflammation (IL-6, CRP, TNF-α). Further, we tested whether inflammation and health behaviors indirectly link personality to health-related quality of life, body mass index, and chronic disease burden using longitudinal mediation in a structural equation modeling framework. RESULTS: Self-reports, informant-reports, and general trait factors of personality predicted future inflammatory biomarker levels (unstandardized regression coefficients ranged -.08 to .07 for self, -.13 to -.10 for informants, and -.16 to -.11 for general). Additionally, all assessment methods of personality were associated with the indicators of physical health through biomarker and health behavior pathways. Effects were primarily found for conscientiousness and neuroticism; IL-6 and CRP were the biomarkers with the most indirect effects; and indirect paths overall emerged more frequently through health behaviors, but this varied by outcome. CONCLUSIONS: Self- and informant-reports provided unique predictive validity of inflammatory biomarkers. Findings highlight the benefits of using of multiple assessments of personality and the importance of examining multiple, distinct pathways by which personality might influence health to understand the mechanisms underlying this relationship more fully. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A mega-analysis of personality prediction: Robustness and boundary conditions.

Decades of studies identify personality traits as prospectively associated with life outcomes. However, previous investigations of personality characteristic-outcome associations have not taken a principled approach to covariate use or other sampling strategies to ensure the robustness of personality-outcome associations. The result is that it is unclear (a) whether personality characteristics are associated with important outcomes after accounting for a range of background variables, (b) for whom and when personality-outcome associations hold, and (c) that background variables are most important to account for. The present study examines the robustness and boundary conditions of personality-outcome associations using prospective Big Five associations with 14 health, social, education/work, and societal outcomes across eight different person- and study-level moderators using individual participant data from 171,395 individuals across 10 longitudinal panel studies in a mega-analytic framework. Robustness and boundary conditions were systematically tested using two approaches: propensity score matching and specification curve analysis. Three findings emerged: First, personality characteristics remain robustly associated with later life outcomes. Second, the effects generalize, as there are few moderators of personality-outcome associations. Third, robustness was differential across covariate choice in nearly half of the tested models, with the inclusion or exclusion of some of these flipping the direction of association. In summary, personality characteristics are robustly associated with later life outcomes with few moderated associations. However, researchers still need to be careful in their choices of covariates. We discuss how these findings can inform studies of personality-outcome associations, as well as recommendations for covariate inclusion. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Detecting Idiographic Personality Change.

Personality changes across the lifespan, but strong evidence regarding the mechanisms responsible for personality change remains elusive. Studies of personality change and life events, for example, suggest that personality is difficult to change. But there are two key issues with assessing personality change. First, most change models optimize population-level, not individual-level, effects, which ignores heterogeneity in patterns of change. Second, optimizing change as mean-levels of self-reports fails to incorporate methods for assessing personality dynamics, such as using changes in variances of and correlations in multivariate time series data that often proceed changes in mean-levels, making variance change detection a promising technique for the study of change. Using a sample of N = 388 participants (total N = 21,790) assessed weekly over 60 weeks, we test a permutation-based approach for detecting individual-level personality changes in multivariate time series and compare the results to event-based methods for assessing change. We find that a non-trivial number of participants show change over the course of the year but that there was little association between these change points and life events they experienced. We conclude by highlighting the importance in idiographic and dynamic investigations of change.

Early Childhood Socioeconomic Status and Cognitive and Adaptive Outcomes at the Transition to Adulthood: The Mediating Role of Gray Matter Development Across Five Scan Waves.

BACKGROUND: Early low socioeconomic status (SES) is associated with poor outcomes in childhood, many of which endure into adulthood. It is critical to determine how early low SES relates to trajectories of brain development and whether these mediate relationships to poor outcomes. We use data from a unique 17-year longitudinal study with five waves of structural brain imaging to prospectively examine relationships between preschool SES and cognitive, social, academic, and psychiatric outcomes in early adulthood. METHODS: Children (n = 216, 50% female, 47.2% non-White) were recruited from a study of early onset depression and followed approximately annually. Family income-to-needs ratios (SES) were assessed when children were ages 3 to 5 years. Volumes of cortical gray and white matter and subcortical gray matter collected across five scan waves were processed using the FreeSurfer Longitudinal pipeline. When youth were ages 16+ years, cognitive function was assessed using the NIH Toolbox, and psychiatric diagnoses, high-risk behaviors, educational function, and social function were assessed using clinician administered and parent/youth report measures. RESULTS: Lower preschool SES related to worse cognitive, high-risk, educational, and social outcomes (|standardized B| = 0.20-0.31, p values < .003). Lower SES was associated with overall lower cortical (standardized B = 0.12, p < .0001) and subcortical gray matter (standardized B = 0.17, p < .0001) volumes, as well as a shallower slope of subcortical gray matter growth over time (standardized B = 0.04, p = .012). Subcortical gray matter mediated the relationship of preschool SES to cognition and high-risk behaviors. CONCLUSIONS: These novel longitudinal data underscore the key role of brain development in understanding the long-lasting relations of early low SES to outcomes in children.

Do correctional facilities correct our youth?: Effects of incarceration and court-ordered community service on personality development.

Millions of individuals are currently incarcerated in the United States. However, little is known about the effects of incarceration on personality development, particularly during the critical life stage of adolescence. In a large longitudinal sample, adolescents and young adults (N = 7,736) regularly completed personality measures and assessments of court-ordered punishments over more than 10 years. Using propensity score weighting and multilevel growth curve modeling, we found that personality prospectively predicted the likelihood of incarceration and court-ordered community service. Specifically, individuals who were higher in sensation seeking, impulsivity, and depressive symptoms were more likely to be incarcerated-results for community service youth mostly mirrored these findings. Mixed evidence was found for patterns of trait change. Incarcerated, community service, and nonoffending youth were similar in several ways-all increased on sensation seeking and self-esteem and decreased on impulsivity over the 10-year period. However, between-person models found that incarcerated youth evidenced a greater decrease in depressive symptoms and a slower decrease in impulsivity, and youth assigned community service increased more quickly on sensation seeking than their nonoffending peers. Within-person analyses also suggested personality differences; for example, sensation seeking was lower after incarceration while impulsivity was higher compared with before. Overall, this work highlights that personality predicts incarceration and court-ordered community service in youth and that personality changes linked with these experiences do not have a uniformly "corrective" pattern of change, with few effects observed overall and some in seemingly unfavorable directions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Bivariate latent change score analysis of peer relations from early childhood to adolescence: Leading or lagging indicators of psychopathology.

Understanding longitudinal associations between problematic peer relations and psychopathology are needed to inform public health. Three models have been proposed: poor peer relations i) lead or are a risk factor for psychopathology; ii) lag or are a consequence of psychopathology; iii) both lead and lag psychopathology. Another model is that poor peer relations lead or lag psychopathology depending upon the developmental period. To test these models, youth's peer relations and clinical symptoms were assessed up to 6 times between ages 3-11 in 306 children. Bivariate latent change score models tested leading/lagging longitudinal relationships between children's peer relations (peer victimization/rejection, peer-directed aggression, social withdrawal, prosocial behavior) and psychopathology (depression, anxiety, and externalizing symptoms). Peer victimization/rejection was a leading indicator of depression from early childhood into preadolescence. Peer-directed aggression was a leading indicator of externalizing symptoms (in late childhood).

Distinct progression patterns across Parkinson disease clinical subtypes.

OBJECTIVE: To examine specific symptom progression patterns and possible disease staging in Parkinson disease clinical subtypes. METHODS: We recently identified Parkinson disease clinical subtypes based on comprehensive behavioral evaluations, "Motor Only," "Psychiatric & Motor," and "Cognitive & Motor," which differed in dementia and mortality rates. Parkinson disease participants ("Motor Only": n = 61, "Psychiatric & Motor": n = 17, "Cognitive & Motor": n = 70) and controls (n = 55) completed longitudinal, comprehensive motor, cognitive, and psychiatric evaluations (average follow-up = 4.6 years). Hierarchical linear modeling examined group differences in symptom progression. A three-way interaction among time, group, and symptom duration (or baseline age, separately) was incorporated to examine disease stages. RESULTS: All three subtypes increased in motor dysfunction compared to controls. The "Motor Only" subtype did not show significant cognitive or psychiatric changes compared to the other two subtypes. The "Cognitive & Motor" subtype's cognitive dysfunction at baseline further declined compared to the other two subtypes, while also increasing in psychiatric symptoms. The "Psychiatric & Motor" subtype's elevated psychiatric symptoms at baseline remained steady or improved over time, with mild, steady decline in cognition. The pattern of behavioral changes and analyses for disease staging yielded no evidence for sequential disease stages. INTERPRETATION: Parkinson disease clinical subtypes progress in clear, temporally distinct patterns from one another, particularly in cognitive and psychiatric features. This highlights the importance of comprehensive clinical examinations as the order of symptom presentation impacts clinical prognosis.

Using idiographic models to distinguish personality and psychopathology.

OBJECTIVE: While the overlap between personality and psychopathology is well documented, few studies examine how the two overlap at a lower, moment-to-moment level. We took an idiographic approach to examine personality and psychopathology processes at the individual level. Doing so offers a unique perspective by incorporating both dynamic time and structural analysis, two components that are traditionally examined separately when investigating the overlap between personality and psychopathology. METHOD: Two experience sample studies measured personality states and personality problems up to four-times a day over a two-week period (Study 1 N = 349, observations = 11,124; Study 2 N = 161, observations = 8,261). RESULTS: For some, personality states and personality problems are deeply intertwined, mirroring existing between-person findings. But for others the two are separate, indicating it is possible to separate personality (states) from a person's problems. Between-person differences in levels of depression had no association with the idiographic structure, indicating that between-person constructs operate separately from within-person processes. Finally, situations that are more likely to bring out personality problems did not alter the association between personality states and personality problems. CONCLUSIONS: This method provides a novel conceptualization of personality-psychopathology overlap, bringing the focus beyond mostly static, between-person models to more dynamic, individual-level models.