Understanding personality pathology in a clinical sample of youth: study protocol for the longitudinal research project 'APOLO'.

Introduction: We propose that a dimensional, multilayered perspective is well suited to study maladaptive personality development in youth. Such a perspective can help understand pathways to personality pathology and contribute to its early detection. The research project 'APOLO' (a Dutch language acronym for Adolescents and their Personality Development: a Longitudinal Study) is designed based on McAdams' integrative three-layered model of personality development and assesses the interaction between dispositional traits, characteristic adaptations, the narrative identity and functioning.