Objective: The COVID-19 pandemic has constituted an unprecedented challenge to society and science and it has provided an unexpected opportunity to explore the effects of a positive intervention in times of adversity and confinement. The goal was to evaluate the effects of a theory driven group intervention to cultivate mental health and flourishing. Design: A pre post design with three groups (151 individuals) was conducted, including an experimental group that received the intervention during the pandemic, a pre-COVID intervention group, and a COVID control group. Main Outcome Measures: Based on Keyes' concept of positive mental health, measures of subjective, psychological and social well-being were obtained, as well as an indicator of psychological distress (GHQ12). Results: Intervention groups showed an increase in well-being and the COVID control group a decrease. Change scores revealed significant differences. Overall percentage of individuals at risk of ill health in baseline was 25.2%, but after the intervention, the COVID control group reached 64.1%. Conclusions: Despite the limitations, the present findings suggest that interventions to sustain and improve mental health in times of crisis and adversity can be an effective approach.The COVID-19 pandemic constitutes an unprecedented challenge to society and science. For psychology and other health professionals, researchers, and academicians, it is a trial to test our ability to fulfil our core mission: "to improve the condition of both the individual and society" (European Federation of Psychologist Associations (EFPA), 2005), and/or to "benefit society and improve people's lives" (American Psychological Association (APA), 2012). In the so-called "normal times", psychology's quest for

The past two decades have witnessed a proliferation of positive psychological interventions for clinical and non-clinical populations, and recent research, including meta-analyses, is providing evidence of its effectiveness. Most interventions have focused on increasing life satisfaction, positive affect, and psychological well-being. Manualized, multi-component interventions based on a comprehensive theory are scarce. Keyes’ concept of mental health and flourishing (subjective, psychological, and social well-being) is an overarching theoretical framework to guide the design of a multi-component psychological intervention to cultivate well-being and personal development. Therefore, the purpose of this study was to design a theory-driven positive intervention and to pilot test the intervention. The manual presents an 8-week group program that includes homework activities. A sample of 56 young adults completed the intervention. Participants were assessed at base line, after termination, and at a 6-month follow-up session. Standardized instruments were used to assess the dimensions of mental health proposed by Keyes. Pre- and post-test measures of subjective, psychological, and social well-being showed significant differences, as did the total mental health scores. At 6-month follow-up, differences remained in subjective and psychological well-being and in positive mental health, with smaller effect sizes. Limitations of these preliminary findings as well as future lines of research and improvements in this manualized intervention are proposed in the light of current research on positive interventions.

Introduction Psychological interventions to cultivate mental health in older adults are scarce and tend to focus on and use a limited number of activities. Objective The aim of this study was to test the effects of an intervention based on Keyes’ concept of positive mental health. Methods The intervention was conducted with 24 self-selected participants, while 34 were part of the control group. Positive mental health and distress outcomes were measured at baseline and at the end of the intervention. ANCOVA analysis and effect sizes were calculated. Results Results showed that the intervention increased mental health (F= 18.22, p<0.001, η 2 = 0.334, d = 1.45, power 0.986) and decreased psychiatric symptomatology in the experimental group versus the control group (F= 7.07, p= 0.011, η 2 = 0.16, d = 0.87, power= 0.736), which showed no change. Discussion Despite study limitations, the intervention effectively promoted older people’s well-being. Future research, should evaluate the long-term effects of the intervention with varied older adult populations.