Key insights from studies on the stability of personality disorders in different age groups.

While for decades, temporal stability has been conceived as a defining feature of personality disorders (PDs), cumulative findings appear to question the stability of PDs and PD symptoms over time. However, stability itself is a complex notion and findings are highly heterogenous. Building upon a literature search from a systematic review and meta-analysis, this narrative review aims to capture key findings in order to provide critical implications, both for clinical practice and future research. Taken together, this narrative review revealed that unlike previous assumptions, stability estimates in adolescence are comparable to stability estimates in adulthood and PDs and PD symptoms are not that stable. The extent of stability itself depends yet on various conceptual, methodological, environmental, and genetic factors. While findings were thus highly heterogenous, they all seem to converge in a notable trend towards symptomatic remission, except for high-risk-samples. This challenges the current understanding of PDs in terms of disorders and symptoms and argues instead in favor of the AMPD and ICD-11 reintroducing the idea of self and interpersonal functioning as the core feature of PDs.

The stability of personality disorders and personality disorder criteria: A systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to investigate the diagnostic, the dimensional mean-level, and rank-order stability of personality disorders (PDs) and PD criteria over time. EMBASE, PsycInfo, PubMed, and Web of Science were searched for peer-reviewed studies published in either English, German, or French between the first publication of the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980 and December 20, 2022. Inclusion criteria were a prospective longitudinal study design, assessing the stability of PDs or PD criteria over at least two measurement occasions at least one month apart, and using the same assessment at baseline and follow-up. Effect sizes included proportion of enduring cases (i.e., diagnostic stability), test-retest correlations (i.e., dimensional rank-order stability), and within-group standardized mean differences (i.e., dimensional mean-level stability), based on the first and last available measurement occasion. From an initial pool of 1473 studies, 40 were included in our analyses, covering 38,432 participants. 56.7% maintained the diagnosis of any PD, and 45.2% maintained the diagnosis of borderline PD over time. Findings on the dimensional mean-level stability indicate that most PD criteria significantly decreased from baseline to follow-up, except for antisocial, obsessive-compulsive, and schizoid PD criteria. Findings on the dimensional rank-order stability suggested moderate estimates, except for antisocial PD criteria, which were found to be high. Findings indicated that both PDs and PD criteria were only moderately stable, although between study heterogeneity was high, and stability itself depended on several methodological factors.

Continuity and Stability of Child and Adolescent Depressive Symptoms in South Korea: A Meta-analysis of Longitudinal Studies.

Many adolescents in South Korea experience risk-level depressive symptoms due to stress caused by personal and environmental changes. Prior studies investigated various characteristics of depressive symptoms. However, it is unclear when the mean level of depression changes with the development of children and adolescents and whether it is stable relative to one another over time. Thus, it is necessary to closely understand the continuity and stability of depressive symptoms across developmental stages in children and adolescents. In this study, continuity refers to the consistency in a group's mean level of depressive symptoms over time; however, stability refers to the consistency in the relative placement of the levels of depressive symptoms of individuals within a group over time. To comprehensively understand previous studies, this meta-analysis compiled data from 95 South Korean longitudinal studies (N = 200,338; 49.7% females) published between 2000 and 2021. Data were analyzed using a three-level random effects model with a 1-year interval for each age group to integrate effect sizes, followed by a generalized additive mixed model integrating age as a continuous variable. The results indicate that the mean-level continuity of depressive symptoms was relatively high and the rank-order stability was low for the children in elementary school (including both upper and lower grades). Additionally, as the adolescents aged, the mean-level continuity of depressive symptoms slightly decreased while stability increased. When entering early adulthood, the continuity and stability of depressive symptoms converged without significant change. As a result of moderating effect, the female-only group indicated a high level of continuity and stability than the male-only or mixed group. The findings highlight that South Korean childhood is a period of relatively high continuity and low stability. Moreover, female students' depressive symptoms fluctuate more than those of males, suggesting the need for providing effective and appropriate help.

Stability and change in autobiographical reasoning: A 4-year longitudinal study of narrative identity development.

OBJECTIVE: Research on personality development has traditionally focused on rank-order stability and mean-level change in the context of personality traits. The present study expands this approach to the examination of change and stability at another level of personality-narrative identity-by focusing on autobiographical reasoning. Drawing from theory in personality and developmental science, we examine stability and change in exploratory processing and positive and negative self-event connections. METHOD: We take advantage of a longitudinal study of emerging adult personality and identity development, which includes four waves of data across 4 years, examining reasoning in two domains of identity, academics, and romance (n = 1520 narratives; n = 176-638 participants, depending on the analysis). RESULTS: We found moderate rank-order stability in autobiographical reasoning, but more so for exploratory processing than self-event connections. We found mean-level increases for exploratory processing in the context of romance and stability in the context of academics. For self-event connections, we saw a decrease for positive connections, and for negative connections about romance, with stability for negative connections about academics. CONCLUSIONS: Implications include developmental differences in types of reasoning as well as the sensitivity of narrative identity to revealing the contextual nature of personality development.

The degree of stability in motor performance in preschool children and its association with child-related variables.

Understanding the stability of individual differences in motor performance during the early years of life, despite normative age-related growth in motor performance, has important implications for identification of motor coordination difficulties and subsequently, early remediation. Therefore, the aims of the present study were to examine the degree of rank-order and individual-level stability in motor performance in young children with different levels of motor skill proficiency. Subsequently, we explored the influence of child variables (i.e., age, gender, and behavioural self-regulation) on different aspects of stability. In this longitudinal study, a community sample of 68 participants (49% girls) with a mean age of 3 years and 11 months (SD = 7 months) were assesses in three six-monthly waves. The total standard score of the Movement Assessment Battery for Children-2 (MABC-2) was used as the measure of motor performance. Rank-order stability was examined with zero-order Pearson correlations. Individual-level stability was examined by means of stability in classifications (at risk for motor coordination difficulties versus typically developing). In addition to examining stability in group classification, the Reliable Change Index (RCI) was calculated to examine if the difference in a child's scores over time exceeded (increased or decreased relative to) the expected change. The results showed moderate to high rank-order stability between time points. No significant differences in degree of rank-order stability were found between boys and girls and between 3-year old and 4-year old children. In terms of stability of classification, it was shown that for ~50% of the children with motor coordination difficulties and ~ 90% of typically developing the classification based on the cut-off score on the MABC-2 was stable. Based on the RCI, over 90% showed individual-level stability. The level of behavioural self-regulation at T1 (as measured with the Head-Toes-Knees-Shoulders task) was not significantly related to individual-level stability in motor performance. In conclusion, our findings highlight the importance of a careful choice of stability measures and a reflection on the implications of their results. More research is needed to understand which child and environmental variables impact on stability.

The Stability and Change of Loneliness Across the Life Span: A Meta-Analysis of Longitudinal Studies.

Individuals experience loneliness when they perceive a deficiency in the quality or quantity of their social relationships. In the present meta-analysis, we compiled data from 75 longitudinal studies conducted in Asia, Australia, Europe, and North America (N = 83, 679) to examine the rank-order and mean-level development of loneliness across the life span. Data were analyzed using two- and three-level meta-analyses and generalized additive mixed models. The results indicate that the rank order of loneliness is as stable as the rank order of personality traits and follows an inverted U-shaped trajectory across the life span. Regarding mean-level development, loneliness was found to decrease throughout childhood and to remain essentially stable from adolescence to oldest old age. Thus, in contrast to other personality characteristics, changes in loneliness are not generally related to age. Implications for theory are discussed.

Cognitive Impairment, Dementia, and Personality Stability Among Older Adults.

There is contrasting evidence on personality stability in advanced age, and limited knowledge on the impact of cognitive impairment and dementia on trait stability. Group- and individual-level longitudinal analyses of the five major dimensions of personality assessed twice over 4 years ( N = 9,935) suggest that rank-order stability was progressively lower with advancing age (from rtt = 0.68 for age 50 to 60 years to rtt = 0.58 for age >80 years). Stability was low in the dementia group ( rtt = 0.43), and this was not simply due to lower reliability given that internal consistency remained adequate in the dementia group. Among individuals with no cognitive impairment or dementia, there was no association between stability and age ( rtt = 0.70 even for age >80 years). These results suggest that the lower personality stability in older adults is not due to age but cognitive impairment and dementia.

The life story from age 26 to 32: Rank-order stability and mean-level change.

OBJECTIVE: In this longitudinal, mixed-methods project, the primary focus was to examine the rank-order stability and mean-level change in the life story during the period of emerging adulthood to young adulthood, while also investigating how the transition to parenthood may impact the life story. METHOD: Seventy-two participants described three key life story scenes at age 26 and again at 32 (28% attrition from age 26 to 32). The narratives were coded for a range of features, including motivational themes (agency, communion), affective themes (emotional tone), an integrative meaning theme (coherent positive resolution), and a structural property (narrative complexity). RESULTS: Overall, there was moderate temporal stability and mean-level increase in several features of narrative identity over this key period. Positive changes in communion levels and overall emotional tone of life story scenes were especially evident for new parents at age 32. CONCLUSIONS: These longitudinal results suggested that adopting new social roles, in this case becoming a parent, predicted how the life story was expressed, just as they seemed to influence other levels of personality, such as traits, following the social investment principle.