A score of 45.6 on the MCS-12 was used as the threshold for depression symptoms, and patients were divided into two groups based on this value: depression (MCS-12 ≤ 45.6) and non-depression (MCS-12 > 45.6) groups.
PCS was associated with anxiety and time since diagnosis and MCS was associated with anxiety and depressive symptoms but not with diabetes duration or metabolic control.
These associations survived adjustment for health conditions but not for lifestyle factors, which explained 81% and 17% of the association with PHQ9-6 and SF36-MCS.
Given the great variability of depressive symptoms in patients with or without self-reported depression and medicated or unmedicated status, we elected to use the MCS classification of depressive symptoms for our analysis.