Depression, anxiety and cognitive function in patients with type 2 diabetes: an 8-year prospective observational study.

Aims: Since depression, anxiety and cognitive function may be impaired in type 2 diabetes, we investigated the relationships between clinical and socioeconomic variables and these psychological dimensions. Methods: For an 8-year prospective observational study of 498 patients, 249 were not insulin-treated (NIT) and 249 were insulin-treated (IT). Demographic, socioeconomic and clinical data were monitored along with depression and anxiety (assessed by Zung questionnaire) and cognitive function by Mini Mental State Examination (MMSE). Results: After 8 years, 131 patients remained NIT (NIT– NIT), 179 remained IT (IT–IT), 47 switched to insulin (NIT–IT), 111 were lost to follow-up and 30 were died. In all groups, HbA1c remained stable, BMI, glucose and lipid profile improved, and foot ulcers and retinopathy worsened. Mild worsening in depression and anxiety scores was observed in the IT–IT patients only. On multivariate analysis, worsening of depression was associated with female gender, disease duration and being IT–IT, and worsening of anxiety with disease duration. Decreased MMSE was associated inversely with smoking and directly with being IT–IT. Conclusions: Patients with type 2 diabetes are at relatively low risk of psycho-cognitive decline. However, being female and on long-term insulin treatment may be risk factors for psychological distress, suggesting that special attention is required for these patients.