Legally enforced quarantines during the COVID-19 pandemic significantly increased psychological distress, especially among individuals with pre-existing depression. A study within the Cologne Corona Counselling and Support project involved 10,033 participants and examined the mental health of infected individuals and their contacts. Results showed that those with depression reported much higher psychological distress compared to those without depression. Additionally, individuals with depression exhibited lower coping and resilience scores and utilized support systems about six times more frequently. Factors contributing to higher distress included being female, younger, more educated, having COVID-19, and having other chronic health conditions. The study highlights the importance of developing tailored interventions to enhance coping skills and resilience for both depressed and non-depressed individuals during quarantines. It emphasizes the necessity of providing adequate therapeutic services and support for those with depression to maintain good mental health during such challenging times.