Defense of the doctoral thesis of Maria Valeria Lavín Gutiérrez

On September 9th, 2026, predoctoral researcher Valeria Lavín Gutiérrez defended her doctoral thesis, entitled «Testing Novel Models of Gene–Environment Interaction Across the Transdiagnostic Mental Health Spectrum». The thesis received the highest possible grade from the examination committee.

The defense was originally scheduled to take place in person in the Sala de Graus at the Faculty of Psychology. However, last-minute heavy-rain alerts and the preventive restrictions introduced in the region of Vallès Occidental meant that the event had to be moved online. Despite this unexpected change, the session proceeded normally.

The thesis, supervised and tutored by Professor Neus Vidal Barrantes, Professor in the Department of Clinical and Health Psychology, examines how genetic factors and environmental experiences interact across different manifestations of mental health. The research adopts a transdiagnostic perspective, which investigates processes shared across different psychological problems beyond traditional diagnostic categories.

One of the central themes of the research is the differential susceptibility model. According to this model, certain genetic characteristics do not simply entail greater vulnerability to adversity; they may also contribute to more positive outcomes when individuals develop in supportive environments.From this perspective, greater sensitivity to the environment is not necessarily a risk factor. Rather, it may increase vulnerability in adverse contexts while also promoting better adaptation and greater well-being in positive and supportive environments.

The thesis comprises six studies and contributes conceptual and methodological innovations to research on gene–environment interaction. Among other aspects, it incorporates the assessment of positive environmental experiences, distinguishes between the influence of maternal figures, paternal figures and peers, and proposes statistical procedures to analyze these interactions with greater precision.

The results, obtained from two independent samples of adolescents and young adults, provide support for the differential susceptibility model across several indicators of mental health, well-being and psychological functioning.

The thesis also proposes studying sensitivity to context in everyday life using ecological momentary assessment methodology. This method makes it possible to collect information through mobile devices several times a day over a period of several days while individuals are in their usual environments. This allows researchers to analyze in greater detail how everyday experiences interact with individual characteristics.

The conclusions of the thesis challenge deterministic interpretations of genetic risk. In other words, having a particular genetic predisposition does not necessarily mean that a person will develop a mental health problem. The findings also highlight the importance of considering both adverse and positive experiences. This perspective may contribute to the design of preventive and therapeutic interventions that focus not only on reducing risk factors, but also on strengthening protective environments, well-being and individuals’ capacity to adapt.

The examination committee was composed of Beatriz Olaya Guzmán, lecturer in the Department of Clinical and Health Psychology at the UAB; Richard Bentall, Professor of Clinical Psychology at the University of Sheffield and a recognized researcher in the study of psychosis and its psychological and social determinants; and Maria del Mar Ariza González, lecturer in the Psychobiology Area of the Department of Clinical Psychology and Psychobiology at the University of Barcelona.

The Department of Clinical and Health Psychology congratulates Valeria Lavín on the quality of her research, on achieving the highest possible grade, and on her ability to adapt to the exceptional circumstances under which the defense had to take place.