Reconsidering the role of depression and common psychiatric disorders as partners in the type 2 diabetes epidemic.

Common psychiatric disorders (CPDs) and depression contribute significantly to the global epidemic of type 2 diabetes (T2D). We postulated a possible pathophysiological mechanism that through Bridge-Symptoms present in depression and CPDs, promotes the establishment of emotional eating, activation of the reward system, onset of overweight and obesity and, ultimately the increased risk of developing T2D. The plausibility of the proposed pathophysiological mechanism is supported by the mechanism of action of drugs such as naltrexone-bupropion currently approved for the treatment of both obesity/overweight with T2D and as separate active pharmaceutical ingredients in drug addiction, but also from initial evidence that is emerging regarding glucagon-like peptide 1 receptor agonists that appear to be effective in the treatment of drug addiction. We hope that our hypothesis may be useful in interpreting the higher prevalence of CPDs and depression in patients with T2D compared with the general population and may help refine the integrated psychiatric-diabetic therapy approach to improve the treatment and or remission of T2D.

Evaluation of the prevalence of the most common psychiatric disorders in patients with type 2 diabetes mellitus using the patient health questionnaire: results of the cross-sectional "DIA2PSI" study.

AIMS: Common Psychiatric Disorders (CPDs) are associated with the development of overweight and obesity, the strongest risk factors for the onset and maintenance of Type 2 Diabetes mellitus (T2D). To the best of our knowledge, this is the first study to assess the prevalence of CPDs in patients with T2D in Italy. METHODS: This is a monocentric cross-sectional study; n = 184 T2D patients were screened for CPDs using the Patient Health Questionnaire (PHQ). Primary outcome was to evaluate the prevalence of CPDs. To assess association between CPDs and risk factors, we have utilized univariable logistic regression models. RESULTS: 64.1% were men, median age was 67 (59-64) and median BMI 27 (25-30) kg/m2. The 42.9% tested positive for one or more mental disorders, 25.6% for depression. Patients with higher BMI (p = 0.04) had an increased likelihood of testing positive to the PHQ. Patients who had implemented lifestyle changes (p < 0.01) and were aware that mental health is linked to body health (p = 0.07) had a reduction in the likelihood of testing positive. CONCLUSIONS: Prevalence of CPDs in T2D patients is higher than in the general population. Since CPDs favor the onset and subsistence of T2D, integrated diabetic-psychiatric therapy is required for improvement or remission of T2D in patients with comorbid CPDs.

Why do we not reverse the path? Stress can cause depression, reduction of brain-derived neurotrophic factor and increased inflammation.

The aim of this paper is to describe the direction of the link between stress, depression, increased inflammation and brain-derived neurotrophic factor (BDNF) reduction. We hypothesize that severe stress or prolonged stress can be the driving factor that promote the onset of depression. Both stress and depression, if not resolved over time, activate the production of transcription factors that will switch on pro-inflammatory genes and translate them into cytokines. This cascade fosters systemic chronic inflammation and reduced plasma BDNF levels. Since people with depression have a 60% increased risk of developing type 2 diabetes (T2D) and show high levels of inflammation and low levels of BDNF, we hypothesize possible reasons that might explain why T2D, depression and dementia are often associated in the same patient.