Background
depression, anxiety
POSITIVE, DISORDERS
 Mental disorders affect millions of people worldwide, causing suffering and various negative consequences. According to the World Health Organization (WHO), the lifetime prevalence ranges from 18.1 to 36.1% [Several studies highlight the psychological burden of the COVID-19 pandemic and related restrictions [For a long time, psychology focused on curing existing psychopathologies. Positive psychology has shifted the focus from dealing only with the negative aspects of life to further improving positive qualities [However, most studies so far have examined individual exercises, but rarely entire holistic training programs. Mostly, such training programs were designed for specific target groups. The first training program of this kind was developed to increase happiness and life satisfaction in college students. It extended over six weeks and was able to significantly increase happiness of the participants [Overall, the literature supports the effectiveness of positive psychology training programs. However, as described above, research so far has focused on testing the effectiveness of such trainings in specific target groups or individual exercises, but not as a holistic training program in the general population. To contribute to closing this research gap, we developed the Positive Emotions Training (PoET) which refers to the promotion of several positive psychology constructs and the improvement of mental health. The development of PoET was based on existing literature on positive psychology treatments as well as long-term discussions among the research group about how to promote respective constructs. For the training, an online format was chosen so that it could be conducted in larger groups despite the prevailing COVID-19 pandemic.We decided to test PoET as an intervention and the methodical approach in a feasibility study. The main goal of this study was to evaluate the practicability of PoET and examine whether it might be an effective intervention to promote mental health. First, we hypothesized that participants receiving PoET would show a significant increase in positive mental health factors one month after the second training day (Hypothesis 1). Second, we expected to find a significant decrease in depression, anxiety, and stress symptoms one month after the second training day (Hypothesis 2). Third, we hypothesized participants in the control group not to show any significant changes in this regard (Hypothesis 3). In addition, we examined whether there might be a significant increase in optimism, gratitude, happiness, resilience, and self-efficacy for participants of PoET in comparison to the control group.