Mental health and type 2 diabetes are closely connected conditions that influence long-term health, daily functioning, and quality of life. Type 2 diabetes requires continuous self-care, while psychological burden can reduce motivation, treatment adherence, lifestyle control, and glucose monitoring. Existing literature shows that depression, anxiety, stress, diabetes distress, and poor sleep are common among patients with type 2 diabetes and may affect glycemic outcomes. However, many studies examine psychological symptoms, HbA1c level, self-management behavior, and complication burden as separate issues, with limited focus on their combined bidirectional relationship. This research is important because diabetes care often prioritizes metabolic control while underestimating emotional and behavioral barriers. This article examines how mental health burden is associated with glycemic control, self-management, and diabetes-related outcomes. The findings indicate that psychological burden may weaken diabetes control, while diabetes difficulty may increase emotional distress. The study concludes that integrated diabetes care should combine clinical monitoring with mental health screening and behavioral support.