The term "depression" refers both to a mood state and, when severe, persistent, and associated with a number of other symptoms, to a clinical syndrome or disorder. Depressive disorders include major depressive disorder, bipolar disorder and dysthymic disorder, a more chronic, less severe form of depression. The term "minor depression" or subthreshold depression refers to depressive symptoms of at least 2 weeks duration that fall short of full diagnostic criteria for a major depressive episode or dysthymic disorder. Symptoms that meet diagnostic criteria for a major depressive episode include some or all of the following characteristics present for at least 2 weeks: a sustained period of low, sad mood, a loss of interest and enjoyment, low energy, sleep disruption, changes in appetite and weight, poor concentration, low self-esteem, feelings of hopelessness and guilt, and, in some cases, thoughts about death and suicide. The lifetime prevalence of major depressive disorder in the general population is more than 15% (79), and is higher in women than in men. Between 2 and 4% of adults in the general population are experiencing a current major depressive episode at any given time (80). Rates of depression are higher in individuals with most major medical conditions, including both DM1 and
DM2. In these conditions, depression is linked to factors such as physical distress and disability, disease severity, prior history of depression and low social support (81). Like eating disorders, depressive symptoms occur along a continuum of severity, and the threshold for clinical concern and intervention should be lower when associated with diabetes than in nonmedical populations.
It has been shown in a variety of studies that depressive disorders are at least twice as common in those with DM1 or DM2, including in children, teens and adults with diabetes, as in the general population (82-86). These findings were supported by a recent meta-analysis of 39 studies including more than 20,000 subjects, which indicated that the risk of depression in diabetes is twice that of the general population (87), and that 29% of adults with either DM1 or DM2 meet lifetime criteria for major depressive disorder. Some studies suggest that depression in individuals with diabetes is characterized by longer episodes, higher recurrence rates and lower recovery rates (88, 89). The association of depression with DM2 appears to be reciprocal, since depression has been identified as a risk factor for the onset of DM2 (90). Further, depression has been associated not only with impaired metabolic control but also with increased mortality in patients with DM2 (91-93).
Women with diabetes are more likely to suffer both from depression and from its consequences. A large meta-analysis (87) demonstrated that the female preponderance of depression in association with diabetes mirrors the increased prevalence of depression in women in the general population (94, 95). Other evidence also suggests that, among those with diabetes, women and those with less education and social support are more likely to be depressed (96, 97). Although biological factors have been proposed to account for the increased risk of depression in women, evidence from the general population suggests that the gender effect may be largely attributed to sociocultural factors, psychological attributes and adverse life events that disproportionately affect women (94).
Both biological and psychological mechanisms have been postulated to account for the relationship between depression and impaired metabolic control in diabetes. The impact of depression on blood sugar levels may be due to its adverse effect on treatment adherence, including managing diabetes self-care tasks and attending medical appointments (98). The relationship between depression and poor compliance with diabetes treatment may be reciprocal. Depression can lead to lower self-efficacy and to self-neglecting and self-defeating behaviors, such as poor adherence to blood glucose monitoring, meal plan and exercise recommendations, while variations in blood sugar level can contribute to depressive symptoms (99). It has also been postulated, but not confirmed, that the metabolic abnormalities associated with diabetes lead to changes in brain structure and function, which then render individuals more susceptible to developing a depressive disorder (100).
The presence of depressive symptoms in patients with diabetes should be of clinical concern for a number of reasons, including their effect on quality of life, health status and healthcare utilization. Major depressive disorder has been estimated to be the fourth leading global cause of disability (101), and is associated with greater decrements in global health scores than asthma, angina or diabetes itself. The combination of diabetes and depression is associated with particularly severe impairment in global health scores and quality of life (102). A recent study of people with diabetes indicated that depression is associated with a 50-75% increase in health services costs, only 15% of which is related to mental health services costs (103). Similar findings were reported by Kalsekar et al. who found that patients with diabetes and depression had nearly 65% higher overall health costs than those without depression (104). A review of cross-sectional, longitudinal and treatment studies of patients with a variety of chronic medical conditions (105) indicated that depression significantly increases functional impairment in these populations, and that its treatment reduces both disability and health service costs. Depressive symptoms have also been associated with impaired metabolic control in patients with DM1 (82, 106,107), and both minor and major depression are associated with increased mortality in patients with DM2 (92).
It has been argued that the threshold for the diagnosis of major depression in current psychiatric diagnostic criteria, such as in the DSM-IV, is too low, and that diagnosing cases of mild to moderate major depressive disorder might be pathologizing normal sadness. In that vein, it has been reported that the majority of individuals with diabetes who have elevated scores on self-report measures of depression do not meet full diagnostic criteria for major depressive disorder (97). However, while this categorical distinction has relevance for psychiatric nosology, evidence suggests that continuous measures of depression best predict difficulties with adherence to diet, exercise and glucose self-monitoring regimens. Further, even low levels of depressive symptoms are associated with nonadher-ence to important aspects of diabetes self-care (107).
Depression may also be of concern in individuals with diabetes because of its association with health risk behaviors and medical morbidity. The health risk behaviors with which depression is associated include cigarette smoking, overeating, physical inactivity and obesity. The adverse effects of which are amplified in those with comorbid diabetes. Whatever the mechanism that accounts for the comorbidity of depression and diabetes, depression has also been associated with an increased risk of diabetes-related medical complications, including sexual dysfunction, retinopathy, nephropathy, heart disease, and stroke (82, 108). Because of the reciprocal relationship between depression and metabolic control, attention to both mood disturbances and to diabetes management may be necessary in order to prevent or delay the progression of diabetes complications.
The emerging Western epidemics of diabetes and obesity are linked (109) and demonstrate some gender effects. The prevalence of obesity is estimated to have increased by 60% in the United States in the past decade (110), and it has been estimated that nearly one in three adults and one in six children and adolescents are now overweight (111). Some research suggests that women have higher obesity rates across all age groups, although these rates are also affected by racial, ethnic and socioeconomic factors (112). It has been suggested that a consistent relationship between obesity and depression has not been demonstrated because of the influence of gender (113). In that regard, in a large study, Istvan and colleagues (114) found a relationship between obesity and depression in women but not in men. Similarly, obesity was associated with a 37% increase in the prevalence of major depressive disorder in women but with a reduction in the prevalence of major depressive disorder in men (115). Other evidence suggests that the association of depression with obesity in women may be mediated through the impact of the latter on self-esteem and body dissatisfaction (113).
The increased health risks associated with depression when comorbid with either eating disorders and/or diabetes is likely due to both biological and behavioral mechanisms. Both depressive symptoms (99, 116) and eating disorders (55, 66) can independently have adverse effects on metabolic control, likely via both behavioral and neuroendocrine pathways. Impaired memory, motivation and problem-solving in either condition, intentional insulin omission in those with eating disorders, and effects of depression on the hypothalamic-adrenal axis and the degree of insulin resistance (86) can all affect metabolic control. Both depression (91) and eating disorders (51, 71) independently increase medical morbidity and mortality rates in individuals with diabetes. In women with either DM1 or DM2, depression is associated with an earlier time to onset of coronary artery disease, independent of other identified risk factors (117). In addition, both depression (118) and disturbed eating behavior (66) are associated with an increased risk of progressive retinopathy.
An enduring significant stressful childhood experience is an established risk factor for depression (119). The ongoing challenges of living with both diabetes may contribute to such stress through its effects on family functioning, social relationships and morale (85). This may account for the finding that teenage girls and women with both diabetes and an eating disorder are more depressed than diabetic controls without an eating disorder (59, 120), and have poorer metabolic control (59). This is of particular concern as early onset depression is more likely to be chronic and severe (121).
The presence of a medical condition, such as diabetes, can adversely affect the body image and self-concept of some women and contribute to a lowering of mood. Those with the onset of diabetes during or prior to childbearing years may worry about their partner's reaction to the condition, its influence on their ability to bear children or the genetic transmission of the disease. Having a chronic medical condition can also contribute to a lack of a sense of control or predictability in relation to the body, to feelings of bodily defectiveness, or to enduring feelings of grief and unfairness related to the diagnosis and burden of the disease. These factors, together with the multiple and complex daily tasks of diabetes management, the difficulty optimizing blood sugar levels the family strain related to managing diabetes, and the risk of diabetes-related medical complications, all may contribute to feelings of frustration, helplessness and depression.
Was this article helpful?
All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.