The interplay of subjective and objective evaluation of psychological distress

Psychological distress is a multidimensional and transdiagnostic construct that cuts across traditional diagnostic boundaries and reflects disruptions in affective, cognitive, behavioral, and somatic regulation. This PhD thesis adopts psychological distress as a central organizing framework and proposes an integrative model based on two complementary and interdependent axes of evaluation: a subjective axis, capturing lived experience and meaning-making, and an objective axis, indexing neurophysiological and autonomic dynamics. The overarching aim is to examine how psychological distress is experienced, expressed, and modulated across different populations and contexts, and how subjective changes relate to embodied physiological processes. Along the subjective axis, the thesis investigates key experiential dimensions of distress, including dissociation, self-hate, spirituality and meaning, and population-level emotional responses to prolonged stressors such as the COVID-19 pandemic and war-related trauma in healthcare workers. Validated self-report instruments and qualitative methods are used to delineate the phenomenology of distress, highlighting both its multidimensional structure and its transdiagnostic relevance. Particular attention is given to dissociation as a core and non-unitary marker of distress, and to the validation of the Italian version of the Multiscale Dissociation Inventory as a clinically meaningful assessment tool. Along the objective axis, psychological distress is examined through neurophysiological and autonomic indices, including EEG markers of cortical regulation and brain–heart interplay measures. Empirical studies focus on anorexia nervosa and cancer-related PTSD, assessing how psychological interventions modulate both subjective experience and physiological regulation. Overall, this work supports an integrative perspective in which subjective phenomenology and objective neurobiological dynamics are understood as interacting dimensions of the same regulatory system. The thesis underscores the clinical and theoretical value of multimodal, temporally sensitive approaches for advancing psychological science and improving the assessment and treatment of psychological distress.