Psychotherapy Change Evaluation: The Self’s Nonlinear Change. A New Mixed Research Method.

The study of psychotherapy and the Self requires a methodology suitable for their complexity, especially when investigating their change. However, quantitative research often creates models based on unrealistic assumptions, such as linearity and homogeneity in how individuals change. These assumptions contribute to a gap between research and clinical practice. Furthermore, most studies assess psychotherapy processes and changes in the Self, relying on a pre-post test logic and losing information about the nature of the change process over time. Consequently, this thesis aims to study the nature of change in psychotherapy and the Self, addressing their complexity. The first chapter describes the ordinary methodology of studying change in psychotherapy. Additionally, it addresses the definition of the Self, its conceptualization as a complex system, and the study of changes in the Self during psychotherapy. The flaws in ordinary methodologies are highlighted, and a contrasting framework is proposed based on idiography, mixed methodology, time series analysis (TSA), ecological momentary assessment (EMA), and dynamic systems theory (DST). Three studies follow. Study 1 (see Chapter 2) aims to investigate the experience of change of psychotherapists. Eight testimonies from expert psychoanalytically oriented psychotherapists were collected and analyzed through a phenomenological approach. The results reveal three categories: common factors across various psychotherapies, specific factors of the psychoanalytic approach, and the processual nature of change. The results show that each individual is unique, so the psychoanalysis must be based on the patient’s characteristics. Therefore, it is impossible to organize therapy into distinct phases, and change takes on an essentially nonlinear process, in contrast to the usual assumptions of linearity and homogeneity of change. Study 2 (see Chapter 3) aims to validate a brief clinical questionnaire for assessing the Self’s dimensions called Self Questionnaire (SQ). Rather than using many self-reports that assess a single facet, which would be burdensome in the case of repeated assessments as is common in EMA studies in psychotherapy, SQ consists of 11 items, each measuring a different facet. Dimensionality assessment was carried out on 515 participants in Italy, and the factorial structure was identified through exploratory graph analysis (EGA). The questionnaire shows good consistency for the two dimensions or communities, Self-Knowledge and Regulation (SKR) and Self-Satisfaction (SS), and a good structure of items and network loadings. Convergent and divergent validity are also acceptable. Study 2 serves as a validation of the SQ, which is used in Study 3. Study 3 (see Chapter 4) proposes a new mixed method for studying changes in the Self in psychotherapy through a single-case pilot study using EMA, TSA, and DST frameworks. Specifically, five participants were recruited and interviewed using the Narrative Assessment Interview (NAI) at the study's beginning and end. From the qualitative analysis, two person-specific items were extracted for each participant. The two person-specific items and the 11 from the SQ were administered weekly through the SEMA3 app at least 30 times, generating time series that were analyzed according to DST and TSA. The feasibility of the method and its informativeness were evaluated. One participant dropped out of the study, and one was removed for compliance lower than 50%. The results show that the trends are linear and nonlinear, and the series are stationary and non-stationary. Moreover, participants can have ARIMA models of different orders for the same SQ item, demonstrating how each person changes differently from others. The signs of the autoregressive (AR) and moving average (MA) components are primarily negative, showing that when the Self deviates from equilibrium, it stabilizes in the next period, confirming its conceptualization as a dynamic system. From the comparison of cross-recurrence quantification analysis (CRQA) between the original and disturbed versions, SKR and SS influence each other bidirectionally, and the parameters are robust to noise. While the method is informative about the course of change of the Self over psychotherapy, feasibility is affected by the available resources, as the project requires economic and time-related investments. Finally, the fifth chapter is the epilogue of the thesis, where general conclusions are drawn based on the studies' results.