Pharmacologically treated depression, anxiety, and insomnia in individuals with type 2 diabetes: The role of diabetes duration, age, and age at diabetes onset. A Norwegian population-based registry study from the OMIT cohort

OBJECTIVE: To examine whether type 2 diabetes (T2D) duration ('0-4'; '≥5-9'; ≥10-19'; '≥20 years') was associated with use of medication for depression, anxiety, or insomnia, and if possible associations were modified by age, age at T2D onset, sex, and education.

METHODS: We used data from 55,083 adults with T2D in the national registry-based cohort study Outcomes & Multi-morbidity In T2D (2006-2019). Adjusted associations and effect modifications were estimated using binary logistic regressions with generalized estimation equations in the subgroups age (<60, ≥60 years), age at diabetes onset (<40, ≥40 years), sex (men, women), and education (primary, high school, university).

RESULTS: At initial registration, 12 % used medication for depression, 10 % for anxiety, and 16 % for insomnia. These prevalence estimates increased with diabetes duration in most subgroups. Individuals with early onset T2D had higher prevalence of depression than those with late onset, which increased with diabetes duration (per category change diabetes duration 0.7 % (95 % CI 0.2, 1.2), P for trend = 0.003). For anxiety and insomnia, a stronger association was found in those with early T2D onset compared to late onset (per category change 1.3 % (95 % CI 0.9, 1.8) and 1.9 (95 % CI 1.3, 2.4), P for interaction = 0.001; 0.01).

CONCLUSION: The prevalence of pharmacologically treated depression, anxiety, and insomnia increased with diabetes duration; this finding may imply that assessment of mental health disorders at the initial phase and along the diabetes trajectory are needed. As the prevalences advanced most prominently in people with early onset T2D, future studies should determine underlying mechanisms to test age-appropriate preventive interventions.