Abstract Introduction. It is claimed that the COVID-19 pandemic has a negative impact on mental health. However, to date, prospective studies are lacking. Moreover, it is important to identify which factors modulate the stress response to the pandemic. Previously, sense of coherence (SOC) has emerged as a particularly important resistance factor. Objective. This prospective study aimed to assess the impact of the COVID-19 outbreak on mental health and to investigate the ability of pre-outbreak SOC levels to predict changes in psychopathological symptoms.Methods. The study assessed psychopathological symptoms and SOC before and after the COVID-19 outbreak as well as post-outbreak COVID-19-related traumatic distress in a German-speaking sample (N=1,591). Bivariate latent change score (BLCS) modelling was used to analyse pre-to-post outbreak changes in psychopathological symptoms and the ability of SOC to predict symptom changes.Results. Overall, there was no change in psychopathological symptoms. However, on individual-respondent level 10% experienced a clinically significant increase in psychopathological symptoms, and 15% met cut-off criteria for COVID-19-related traumatic distress. Using BLCS modelling, we identified a high-stress group experiencing an increase in psychopathological symptoms and a decrease in SOC and a low-stress group showing the reversed pattern. Changes in SOC and psychopathological symptoms were predicted by pre-outbreak SOC and psychopathological symptom levels. Conclusions. Although mental health was stable in most respondents, a relevant proportion of the sample experienced increased psychopathological symptoms due to COVID-19. Since higher SOC was predictive of smaller changes in symptom levels, SOC training might be a promising approach to enhance resistance to stressors.