Too puzzled to progress: Identity formation as a key developmental process and a central issue within personality pathology in community and clinical samples

Identity formation is a key developmental process that unfolds across the lifespan. Especially during adolescence and emerging adulthood, young individuals search for a (new) sense of coherence and continuity, which enables them to move through life with purpose, and experience feelings of personal meaning and well-being. Problems associated with identity formation are considered a core symptom of personality pathology. Consequently, the current dissertation aims to improve our understanding of identity formation and how it relates to personality pathology. Specifically, we first investigated normative identity formation in adolescence and emerging adulthood (Part I; Chapter 2-3). Second, in an attempt to cover both normative and pathological identity functioning, we evaluated the psychometric properties of the Dutch Self-Concept and Identity Measure (SCIM), a self-report instrument designed to assess the full spectrum of identity functioning (Part II; Chapter 4-5-6). Finally, we investigated whether identity disturbance represents a transdiagnostic symptom of all personality disorders and other forms of psychopathology (i.e., depression and anxiety; Part III; Chapter 7-8). The results of the seven empirical chapters are summarized below.In Chapter 2, we investigated gender-moderated age trends in identity synthesis and confusion, and associations with depressive symptoms among 12-to 25-year-old community individuals. We found that, over time, young individuals' sense of identity developed towards a predominantly synthesized sense of identity, and that girls took a longer time to arrive at a sense of identity synthesis than boys. Among early, mid-, and late adolescents, identity confusion was positively associated with depressive symptoms.In Chapter 3, we investigated the directionality of between- and within-person effects linking identity synthesis and confusion to processes of exploration and commitment among community adolescents. At both the between- and within-person level, identity synthesis positively predicted proactive identity exploration. Only at the between-person level, a bidirectional effect emerged: identity synthesis positively predicted identification with commitment, whereas identification with commitment negatively predicted identity confusion.In Chapters 4, 5, and 6, we evaluated the psychometric properties of the Dutch SCIM among community adolescents, community adults, and inpatients with personality disorders. Across all samples, the factor structure, reliability, and convergent validity of the Dutch SCIM could be established. Furthermore, SCIM scales indicative of a disturbed identity and a lack of identity were positively associated with symptoms of all personality disorders, depression, and anxiety.In Chapters 7 and 8, we established identity disturbance as a transdiagnostic symptom of all personality disorders. We found that low levels of commitment and high levels of ruminative exploration, disturbed identity, and lack of identity were positively associated with symptoms of all personality disorders among community (emerging) adults.In summary, this dissertation demonstrates that the development of a synthesized sense of identity is a process that takes time and allows individuals to proactively explore future orientations. When identity development is derailed or disrupted, individuals seem to be at risk of experiencing (symptoms of) personality disorders, depression, and anxiety. As identity disturbance can be considered a transdiagnostic symptom that cuts across traditional diagnostic boundaries, we should attend to it within the treatment of individuals with psychiatric disorders.

Jaar van publicatie:2022

Toegankelijkheid:Embargoed