INS and type 2 diabetes mellitus: In both depression and CPDs, there are other pathological mechanisms that can lead to increased risk of developing T2D: systemic chronic inflammation, increased insulin resistance, decreased insulin release from pancreatic beta cells and cognitive mechanisms like decreased ability to think and to focus, anhedonia, weariness, and lack of motivation that negatively affect the probability of attending medical examination and check-up or sustaining a physically active lifestyle [17].