Young people with chronic illnesses including type 1 diabetes mellitus (T1DM) are at increased risk of developing psychological problems during adolescence. The aim of the present study was to explore whether a relationship exists between developmental challenges of adolescence (eating attitudes, family support and fear of negative evaluation) and psychopathology in adolescents with T1DM, and the nature of such a relationship. Sixty-one adolescents with T1DM completed a series of questionnaires assessing illness beliefs, eating attitudes, family support, Fear of Negative Evaluation (FNE) and psychopathology. The study was of a correlational design, and also included a seven-day diabetes management diary in order to collect blood glucose levels over this time. Results demonstrated the relevance of all three developmental challenges. In multiple regression analyses, FNE and eating attitudes independently predicted current levels of depressive symptomatology. Current levels of anxiety were predicted by FNE and family support, but not eating attitudes. The results support the relevance of all three developmental challenges of adolescence to psychopathology in young people with diabetes. These results suggest that in working with adolescents who are having difficulty coping with diabetes; it may be beneficial to focus on the developmental issues that commonly face adolescents.