Recent research in psychiatric genetics has led to a move away from simple diathesis-stress models to more complex models of psychopathology incorporating a focus on gene–environment interactions and epigenetics. Our increased understanding of the way biology encodes the impact of life events on organisms has also generated more sophisticated theoretical models concerning the molecular processes at the interface between “nature” and “nurture.” There is also increasing consensus that psychotherapy entails a specific type of learning in the context of an emotional relationship (i.e., the therapeutic relationship) that may also lead to epigenetic modifications across different therapeutic treatment modalities. This paper provides a systematic review of this emerging body of research. It is concluded that, although the evidence is still limited at this stage, extant research does indeed suggest that psychotherapy may be associated with epigenetic changes. Furthermore, it is argued that epigenetic studies may play a key role in the identification of biomarkers implicated in vulnerability for psychopathology, and thus may improve diagnosis and open up future research opportunities regarding the mechanism of action of psychotropic drugs as well as psychotherapy. We review evidence suggesting there may be important individual differences in susceptibility to environmental input, including psychotherapy. In addition, given that there is increasing evidence for the transgenerational transmission of epigenetic modifications in animals and humans exposed to trauma and adversity, epigenetic changes produced by psychotherapy may also potentially be passed on to the next generation, which opens up new perspective for prevention science. We conclude this paper stressing the limitations of current research and by proposing a set of recommendations for future research in this area.

Depressive symptomatology and psychological well-being among Chilean university students Background: Quality of life and psychological well-being are readily hampered by depression. The changes that students face during college life impact their psychological health and well-being, including the emergence of mental health problems like depression Aim: To determine the relationship between depressive symptoms, sociodemographic parameters and psychological well-being in undergraduate university students. Material and Methods: Five hundred eighty university students of both sexes, from the Metropolitan and IX Regions of Chile answered the Beck Depression Inventory (BDI-IA) and the Ryff's psychological well-being scale. Results: Twenty eight percent of respondents had clinically significant depressive symptoms, and these were more frequent in women. There was an inverse and statistically significant relationship between psychological well-being and depressive symptoms. This fact was especially marked in dimensions of autonomy, positive relationships with others and purpose in life. Conclusions: There is a high frequency of depressive symptoms among these students. We discuss whether psychological well-being and depressive symptomatology represent two extremes within a continuum or they are two independent dimensions that can account for differential causal mechanisms linked to mental health and illness.

L a depresión es una enfermedad recurrente, frecuentemente crónica y que requiere un tratamiento a largo plazo 1 . Su prevalencia en la población general se encuentra entre 8 y 12% 2 . Se estima que para el año 2030 ocupará el primer lugar en la medición de carga de enfermedad según los años de vida ajustados por discapacidad 3 . A pesar de esto, su diagnóstico aún continúa planteando múltiples desafíos tanto conceptuales como clínicos. Con el objeto de resolver los problemas de validez y confiabilidad de los criterios diagnósticos, en la actualidad se ha impuesto un modelo ateórico, (representado por el Diagnostic and Statistic Manual of Mental Disorders, DSM y la Clasificación Internacional de Enfermedades, CIE) cuya utilidad ha sido cuestionada, no encontrándose hasta el momento una solución definitiva 4 . Ante esta realidad clínica subyace un problema grave y complejo. La evidencia muestra que para los propios psiquiatras existen importantes dificultades al momento de plantear un diagnóstico que resulte adecuado para el cuidado de los pacientes depresivos 5 y no es de extrañar que el médico general tenga al menos las mismas dificultades. Así, se ha visto que en atención primaria de salud (APS), la depresión suele ser sobrediagnosticada, subdiagnosticada y tratada de manera insuficiente 6-8 .El objetivo de este trabajo es revisar el constructo de la depresión desde el punto de vista del diagnóstico psiquiátrico, considerando aspectos clínicos ("espectro afectivo"), socioculturales, etiopatogénicos y caracterológicos. La tesis que guía esta revisión es que la depresión debe comprenderse según una concepción de la relación mente-cerebro, entendida como un sistema complejo y que, por lo tanto, debe ser analizada desde múltiples perspectivas 9 . Para eso, plantearemos un modelo integrado que facilite al médico el buen desarrollo de su juicio clínico mientras trabaja con

Research on the potential role of gene–environment interactions (GxE) in explaining vulnerability to psychopathology in humans has witnessed a shift from a diathesis-stress perspective to differential susceptibility approaches. This paper critically reviews methodological issues and trends in this body of research. Databases were screened for studies of GxE in the prediction of personality traits, behavior, and mental health disorders in humans published between January 2002 and January 2015. In total, 315 papers were included. Results showed that 34 candidate genes have been included in GxE studies. Independent of the type of environment studied (early or recent life events, positive or negative environments), about 67–83% of studies have reported significant GxE interactions, which is consistent with a social susceptibility model. The percentage of positive results does not seem to differ depending on the gene studied, although publication bias might be involved. However, the number of positive findings differs depending on the population studied (i.e., young adults vs. older adults). Methodological considerations limit the ability to draw strong conclusions, particularly as almost 90% (n = 283/315) of published papers are based on samples from North America and Europe, and about 70% of published studies (219/315) are based on samples that were also used in other reports. At the same time, there are clear indications of methodological improvements over time, as is shown by a significant increase in longitudinal and experimental studies as well as in improved minimum genotyping. Recommendations for future research, such as minimum quality assessment of genes and environmental factors, specifying theoretical models guiding the study, and taking into account of cultural, ethnic, and lifetime perspectives, are formulated.