Background: Type 1 diabetes mellitus (T1DM) is one of the most widespread chronic endocrine diseases among children and adolescents globally. Many barriers contribute to the challenge of adherence to treatment regimens among adolescents with T1DM.

Objective: This study explores the barriers that influence adherence to treatment regimens among adolescents with T1DM.

Methods: Cross-sectional, descriptive, and exploratory designs were utilized. Convenience sampling was used to recruit 76 adolescents with T1DM from three hospitals in Jordan who were asked to complete the T1DM Parents' and Adolescents' Knowledge Questionnaire- related barriers section (T1DM-PAKQ).

Results: The multiple regression revealed that six out of 12 factors significantly explained about 32% of the model. Barriers significantly affect adherence to the treatment regimen among adolescents with T1DM include: psychological support (β= .998, t= 21.218, p<.001), the cost of reaching the hospital (β= .961, t= 13.810, p <.001), time available to communicate with the physician (β = .981, t= 16.524, p <.001), overcrowding of the outpatient clinic (β = .921, t= 11.269, p <.001), the hospital is far from home (β = .885, t= 10.221, p <.001), sick leave from my school or workplace (β = .880, t= 9.939, p <.001). 

Conclusion: For individuals with T1DM, adherence to a treatment regimen is crucial for managing the condition effectively and maintaining overall health. The findings from the present study suggest that adolescents' adherence to treatment regimens is influenced by barriers that could be managed.

Implication for Nursing: Nurses in different positions should support adolescents with T1DM and adherence to treatment regimens.

Keywords: Adolescents; Type 1 Diabetes Mellitus; Barriers; Treatment regimen; Adherence