Background <p>People affected by mental illness were particularly affected by the burden caused by measures to fight the COVID-19 pandemic. The simultaneous reduction in professional support services resulted in bottlenecks. The study examines how families with members suffering from mental health problems and professionals specializing in psychosocial care, perceived the pandemic and the associated restrictions. The focus is on the functionality of institutions and professional support, the consequences of care deficits and potential approaches to improve psychosocial care in crisis situations.</p> Methods <p>Qualitative analysis based on 12&#xa0;guided interviews (adults and families affected by mental illness) as well as 2&#xa0;focus group interviews with mental health care professionals.</p> Results <p>Adults suffering from mental health problems who had continuous access to institutional care during the pandemic reported relatively high levels of satisfaction with the support systems. The loss of educational and childcare services (such as kindergarten, school and after school care), in particular, was not compensated by healthcare services and the child and youth welfare system. Families affected by mental illness, already under significant stress, were particularly overburdened by school closures, which were identified as a&#xa0;key stress factor.</p> Conclusion <p>The closure of schools and the loss of childcare services have the potential to cause substantial harm to vulnerable families. It is recommended that future measures be implemented, consisting of low-threshold, crisis-proof and interconnected support services. To ensure the provision of mandatory care in times of crisis, it is essential that psychosocial service providers have knowledge of the vulnerable populations under their care. The enhancement of networking among support systems is imperative to ensure the provision of needs-based assistance.</p>