Originally, she read History at the University of Oxford, but after two years she was forced to cut her studies short due to illness.
Later, in 1931, Addis decided to go to the London School of Economics where she became interested in the idea of child guidance which led her to apply for their Mental Health Course.
Addis attended the University of Oxford to read History for two years before having to cease her studies due to illness.
After this period of time and upon deciding that she did not wish to continue working with manuscripts, Addis attended the London School of Economics with the idea of pursuing teaching and child psychology.
Due to credits from previous studies at LSE and practical experience before enrolling, Addis was able to skip the normal to year Social Science diploma that was expected from the course.