In all cases you will receive advice and help from the responsible youth welfare office and the addiction counseling centers.
Youth welfare office, Office for Social Services in Bremen https://www.service.bremen.de/de/dienststelle/bremen2010.c.14213581.de
Child and youth protection telephone (Kinder- und Jugendschutztelefon): Under phone number 0421-699 11 33 you can reach experienced professionals who help in crisis situations.
Addiction counseling centers:
Health Department Bremen https://www.gesundheitsamt.bremen.de/detail.php?gsid=bremen125.c.1839.de
Caritas Bremen: https://www.caritas-bremen.de/beratung-hilfe/bei-sucht/sucht
Outpatient addiction help: https://ash-bremen.de/