A Study to Test Different Doses of BI 1569912 in People With Depression Who Take Anti-depressive Medicine

This study is open to adults between 18 and 65 with a type of depression (major depressive disorder) for whom previous treatments for depression did not work. The purpose of the study is to find out whether a medicine called BI 1569912 helps people with depression. Participants continue their standard therapy throughout the study. Participants are put into 4 groups by chance. 3 of the 4 groups take different doses of BI 1569912. 1 group takes placebo. Placebo tablets looks like BI 1569912 but do not contain any medicine. Participants take the tablets once a day for 6 weeks. Participants are in the study for about 2 to 4 and a half months. During this time, they visit the study site at least 6 times. At the visits, doctors ask participants about their symptoms. The participants answer questions about their depression symptoms. The results are compared between the groups. The doctors also regularly check the general health of participants.