Unraveling the Mechanisms Responsible for the Comorbidity between Metabolic Syndrome and Mental Health Disorders

Abstract

The increased prevalence and high comorbidity of metabolic syndrome (MetS) and mental health disorders (MHDs) have prompted investigation into the potential contributing mechanisms. There is a bidirectional association between MetS and MHDs including schizophrenia, bipolar disorder, depression, anxiety, attention-deficit/hyperactivity disorder, and autism spectrum disorders. Medication side effects and social repercussions are contributing environmental factors, but there are a number of shared underlying neurological and physiological mechanisms that explain the high comorbidity between these two disorders. Inflammation is a state shared by both disorders, and it contributes to disruptions of neuroregulatory systems (including the serotonergic, dopaminergic, and neuropeptide Y systems) as well as dysregulation of the hypothalamic-pituitary-adrenal axis. MetS in pregnant women also exposes the developing fetal brain to inflammatory factors that predispose the offspring to MetS and psychopathologies. Due to the shared nature of these conditions, treatment should address aspects of both mental health and metabolic disorders. Additionally, interventions that can interrupt the transfer of increased risk of the disorders to the next generation need to be developed.

Components of the metabolic syndrome and depressive symptoms in community-dwelling older people: the Bambuí Cohort Aging Study

“…27 Such abnormalities are also observed in depressed patients of all ages, and can be considered as a neurobiological link between MetS and depression. 28,29 It is interesting that in our study high triglyceride levels was the MetS component with the most significant association with depressive symptoms. This highlights the relevance of the emergence of depressive symptoms in older adults to ensue lipid metabolism abnormalities.…”

Effect of Metabolic Syndrome on Depression in Mice

“…Both epidemiological and animal studies have shown obesity to be a risk factor for mood disorders including depression. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] Diabetic rats have also been shown to develop signs of depression. 40,41 However, how obesity or diabetes may lead to depression is not very well characterized.…”

“…24 HPA axis may play a major role in the pathogenesis of MetS. 25 Obese individuals may exhibit elevated plasma cortisol. 26 On the other hand, higher evening cortisol level has been observed in patients suffering from a major depressive disorder.…”

The Effects of Episodic Versus Continuous and Major Versus Mild Depression and Anxiety Symptoms on Pregnancy and Labour Complications

“…These include inflammation and dysregulation of the hypothalamicpituitary-adrenal axis may alter the hypothalamic pituitary adrenal axis, in which elevates plasma adrenocorticotropic hormone and cortisol levels, which increases the release of placental corticotropinreleasing hormone, and can further increase of the release of adrenocorticotropic hormone and cortisol [37,38].…”

“…The association between swelling/edema and summative support was positive and married participants were 47% less likely to have swelling/edema during pregnancy. Women in the older category (29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44) were significantly more likely to have swelling/ edema during pregnancy.…”