Assessment of Depressive Symptoms in Patients with Type 1 and Type 2 Diabetes Mellitus and with Diagnosed Prediabetes in Poland: A Cross-Sectional Study

<b>Background/Objectives</b>: Diabetes mellitus is one of the most common chronic diseases worldwide. In addition to short-term and long-term complications, diabetes has a detrimental effect on the patients' mood. The main psychiatric disorder occurring among diabetic patients is depression. The rates of depression in the developed and developing countries are 15% and 11%, respectively. This study aimed to determine the prevalence of depressive symptoms among patients with type 1 and type 2 diabetes and prediabetes in Poland using the example of the Podlaskie Province and taking into account selected sociodemographic variables. <b>Methods</b>: A total of 874 patients participated in the study, including 448 women (55.8%) and 386 men (44.2%). The study was conducted from July 2022 to July 2023 among the participants of the "Zatrzymaj cukrzycę! Polski Rejestr Diabetologiczny PolRed" ("Stop Diabetes! Polish Diabetes Registry (PolRed)") project or those hospitalised in the Department of Endocrinology, Diabetology and Internal Medicine at the University Clinical Hospital in Bialystok. The study used a diagnostic survey method using a survey questionnaire developed by the authors and the Beck Depression Inventory (BDI). <b>Results</b>: The highest severity of depressive symptoms according to the Beck Depression Inventory was found in patients with type 2 diabetes (M = 12.18; SD ± 9.48) and the lowest in those with type 1 diabetes (M = 8.11; SD ± 7.55). The assessment of the differences in the severity of depressive symptoms according to the Beck Depression Inventory showed that participants with type 1 diabetes differed statistically significantly (<i>p</i> < 0.001) from those with type 2 diabetes and from those in a prediabetic state. In the group of type 2 diabetes (r = 0.336; <i>p</i> < 0.001) patients and prediabetic state patients (r = 0.231; <i>p</i> < 0.01), there were positive correlations of age with the severity of depressive symptoms. In the group of participants with type 2 diabetes, a statistically significant relationship (<i>p</i> < 0.001) was observed between age and the severity of depressive symptoms. <b>Conclusions</b>: The prevalence of mood disorders in patients with type 1 and type 2 diabetes and diagnosed prediabetes from the Podlaskie Province depends on the type of hyperglycaemic disorder. The prevalence of depressive symptoms among patients with type 1 and type 2 diabetes and prediabetes is determined by specific socio-demographic factors, including, above all, age and gender. The highest severity of a disturbed emotional state according to the Beck Depression Inventory is found in individuals with type 2 diabetes and the lowest in those with type 1 diabetes.