Significance: The current study quantified the degree to which group data are able to describe individual participants. We utilized intensive repeated-measures data—data that have been collected many times, across many individuals—to compare the distributions of bivariate correlations calculated within subjects vs. those calculated between subjects. Because the vast majority of social and medical science research aggregates across subjects, we aimed to assess how closely such aggregations reflect their constituent individuals. We provide evidence that conclusions drawn from aggregated data may be worryingly imprecise. Specifically, the variance in individuals is up to four times larger than in groups. These data call for a focus on idiography and open science that may substantially alter best-practice guidelines in the medical and behavioral sciences.

Background: This meta-analysis seeks to quantify the prospective association between neuroticism and the common mental disorders (CMDs, including anxiety, depression, and substance abuse) as well as thought disorders (psychosis/schizophrenia) and non-specific mental distress. Data on the degree of confounding of the prospective association of neuroticism by baseline symptoms and psychiatric history, and the rate of decay of neuroticism's effect over time, can inform theories about the structure of psychopathology and role of neuroticism, in particular the vulnerability theory.Method: This meta-analysis included 59 longitudinal/prospective studies with 443 313 participants.Results: The results showed large unadjusted prospective associations between neuroticism and symptoms/diagnosis of anxiety, depression, and non-specific mental distress (d= 0.50–0.70). Adjustment for baseline symptoms and psychiatric history reduced the associations by half (d= 0.10–0.40). Unadjusted prospective associations for substance abuse and thought disorders/symptoms were considerably weaker (d= 0.03–0.20), but were not attenuated by adjustment for baseline problems.Unadjustedprospective associations were four times larger over short (<4 year) than long (⩾4 years) follow-up intervals, suggesting a substantial decay of the association with increasing time intervals.Adjustedeffects, however, were only slightly larger over shortv.long time intervals. This indicates that confounding by baseline symptoms and psychiatric history masks the long-term stability of the neuroticism vulnerability effect.Conclusion: High neuroticism indexes a risk constellation that existspriorto the development and onset of any CMD. The adjusted prospective neuroticism effect remains robust and hardly decays with time. Our results underscore the need to focus on the mechanisms underlying this prospective association.

High neuroticism predicts psychopathology and physical health problems. Nongenetic factors, including major life events and experiences, explain approximately half of the variance in neuroticism. Conversely, neuroticism also predicts these life experiences. In this study, we aimed to quantify the reciprocal causation between neuroticism and life experiences and to gauge the magnitude and persistence of these associations. This longitudinal cohort study included 5 assessment waves over 16 years in a random sample of 296 Dutch participants (47% women) with a mean age of 34 years (SD = 12, range 16-63 years). Neuroticism was assessed with the Amsterdam Biographic Questionnaire. The experiences measured included positive and negative life events, long-term difficulties (LTDs), and change in life quality, all assessed by contextual rating procedures adapted from the Life Event and Difficulties Schedule. We fit structural equation models in Mplus. Results showed that neuroticism consistently predicted negative experiences, decreased life quality, and LTDs (β = 0.15 to 0.39), whereas effects on positive experiences were variable (β = 0.14). LTDs and deteriorated life quality each predicted small but persistent increases in neuroticism (β = 0.18), whereas improved life quality predicted small but persistent decreases (β = -0.13). This suggests set point change in neuroticism. Life event aggregates showed no persistent effects on the neuroticism set point. Neuroticism and life experiences showed persistent, bidirectional associations. Experience-driven changes in neuroticism lasted over a decade. Results support the corresponsive principle (reciprocal causation), suggesting a mixed model of change in neuroticism that distinguishes temporary changes in neuroticism from persistent changes in an individual's neuroticism set point.

Aims.: For the past quarter of a century, Franket al.’s (1991) consensus-based definitions of major depressive disorder (MDD) episode, remission, recovery, relapse and recurrence have been the paramount driving forces for consistency in MDD research as well as in clinical practice. This study aims to review the evidence for the empirical validation of Franket al.’s proposed concept definitions and to discuss evidence-based modifications.Methods.: A literature search of Web of Science and PubMed from 1/1/1991 to 08/30/2017 identified all publications which referenced Franket al.’s request for definition validation. Publications with data relevant for validation were included and checked for referencing other studies providing such data.Results.: A total of 56 studies involving 39 315 subjects were included, mainly presenting data to validate the severity and duration thresholds for defining remission and recovery. Most studies indicated that the severity threshold for defining remission should decrease. Additionally, specific duration thresholds to separate remission from recovery did not add any predictive value to the notion that increased remission duration alleviates the risk of reoccurrence of depressive symptoms. Only limited data were available to validate the severity and duration criteria for defining a depressive episode.Conclusions.: Remission can best be defined as a less symptomatic state than previously assumed (Hamilton Rating Scale for Depression, 17-item version (HAMD-17) ⩽4 instead of ⩽7), without applying a duration criterion. Duration thresholds to separate remission from recovery are not meaningful. The minimal duration of depressive symptoms to define a depressive episode should be longer than 2 weeks, although further studies are required to recommend an exact duration threshold. These results are relevant for researchers and clinicians aiming to use evidence-based depression outcomes.

Theories on children and adolescent emotion dynamics were reviewed using data from 102 ecological momentary assessment studies with 19,928 participants and 689 estimates. We examined age-graded differences in emotional intensity, variability, instability, inertia, differentiation, and augmentation/blunting. Outcomes included positive versus negative affect scales, discrete emotions (anger, sadness, anxiety, and happiness), and we compared samples of youth with or without mental or physiological problems. Multilevel models showed more variable positive affect and sadness in adolescents compared with children, and more intense negative affect. Our additional descriptive review suggests a decrease in instability of positive and negative emotions from early to late adolescence. Mental health problems were associated with more variable and less intense positive affect, and more intense anxiety and heightened sadness variability. These results suggest systematic changes in emotion dynamics throughout childhood and adolescence, but the supporting literature proved to be limited, fragmented, and based on heterogeneous concepts and methodology. (PsycInfo Database Record (c) 2022 APA, all rights reserved).