Psychological stress has been implicated in the onset and course of diabetes mellitus. Epidemiological, clinical and experimental evidence is available for such an association. Relaxation response refers to methods that can be applied to counter the effect of stress, a “wakeful hypometabolic state that allows an individual to maintain optimal stress level”. They fall under the mind-body techniques and include yoga, meditation, mindfulness based stress relief methods. A variety of techniques are employed such as muscle relaxation, autogenic training, relaxation response and transcendental meditation.
Diabetes mellitus is a complex, chronic medical condition that requires a high degree of patient self-management and social support as a part of effective and comprehensive intervention plan. Psychological stress and psychiatric illness can negatively influence patient's capacity for selfmanagement besides having direct and independent effects on the disease process.1 Psychological factors have been shown to impair glycemic control and increase the risk of complications due to diabetes mellitus.2,3 Therefore, attention to psychological aspects of diabetes mellitus is particularly important both in terms of improvement in diabetes related parameters as well as to enhance emotional health and quality of life of the patients as well as caregivers.
PSYCHOSOCIAL STAGES OF DIABETES
The psychological status of patients with diabetes varies with the stage of the illness, complications, social support, work and family environment, and a host of other factors. In order to systematically study psychological status of a patient with diabetes mellitus, the course of the illness can be divided into four psychosocial stages.4 The emergence of each of these stages also marks the time periods during which the psychological stress and psychiatric symptoms are most likely to emerge or exacerbate. Knowledge of these stages can also be of help to the therapist to plan appropriate psychological intervention strategies.
The first stage is associated with the onset of the illness. During this stage, the patient has to come to terms with the fact that “I am ill” and the consequent ramifications. An adaptive crisis can occur at this stage. The second stage is the preventative stage during which the patient is faced with a daunting task of learning as well as regularly following a complex, demanding therapy even if there is no immediate benefit. A patient who has not adequately resolved the first stage is faced with a new psychological challenge that might further escalate the situation. The third stage is the stage of development of early complications during which the scary facts embed themselves and the patient discovers a frightening new side of the illness along with the associated task of adjusting to the same. The final stage is the stage of the complications dominating the illness. In this stage, the patient's view of self is altered as a result of the “new illnesses” that he has developed.
Thus, for a patient, diabetes is not one illness but many illnesses, with each having a different psychological meaning and impact and possibly requiring differing psychological interventions depending on the stage of the illness and state of the individual patient. The stages are summarized in Figure 1.
SOURCES OF PSYCHOLOGICAL STRESS IN DIABETES MELLITUS
Stress, a concept put forth by Hans Selye, has become increasingly relevant to the understanding of etiopathogenesis as well as management of chronic medical disorders. It is used to describe all physical, psychological or social phenomena that tax an individual in such a way that physical, psychological or social change results. Different models have been proposed to explain stress paradigm. The biomedical perspective conceptualizes stress as stimulus based (sum total of sum of biological and psychological disturbances). The psychological perspective describes it as a response-based concept. Finally, sociological perspective conceptualizes stress as outcome of interaction between environmental demands and individuals response. Various internal and external factors play a role in the subjective experiences and responses. This can be understood using the models proposed by Cohen et al. (1977),5 and Taylor and Aspinwall (1996).6 Figure 2 presents an adaptation based on these models.
Psychological stress in diabetes might emanate from various sources or situations. Illness characteristics, the patient's psychological makeup, personality characteristics and his adjustment to the illness are primary sources of stress. This has been partly discussed above. Skinner et al.7 examined the big five inventory personality traits and a host of other variables in 1,313 participants with type 2 diabetes mellitus (T2DM) in the Fremantle Diabetes Study.
They observed that patients high on conscientiousness were less likely to be obese, smoke and more likely to self-monitor glucose levels as well as take medications. However, there was no independent association between personality traits and hemoglobin A1c (HbA1c) levels. Jokela et al.8 conducted a pooled analysis of five cohort studies examining personality and risk of diabetes. They concluded that low conscientiousness is associated with higher risk of diabetes and diabetes related mortality. The other sources arise from the patient's environment, which include his family environment and the work environment.
Family stress plays an important role in diabetes mellitus in general, although it is particularly well studied in case of young patients with type 1 diabetes. Anderson9 in a qualitative review suggested that high levels of diabetes related familial conflict and authoritarian parenting with unreasonable demands were related to poorer treatment adherence and glycemic control. Laffel et al.10 concluded that patient reported diabetes related family conflict was a significant predictor of their quality of life. Duke et al.11 measured family behavior and concluded that it explained around 12% of the variability in glycemic control. Also, more judgmental parenting was associated with higher HbA1c levels. Lewin et al.12 observed that children and adolescents with single parent had poorer glycemic control than those with both parents. They also observed that family stress contributed to poorer glycemic control irrespective of socioeconomic status. These studies highlight the relationship between family stress and glycemic control among those diagnosed with diabetes mellitus.
Family stress leads to problematic child behavior which in turn leads to poorer glycemic control. Therefore, interventions in dysfunctional families may lead to improvement in glycemic control although some studies suggest otherwise.13 Family involvement also predicts glycemic control as parents’ behavior is one of the factors for creating independent and responsible patients who can take care of their illness. Participation of entire family in educational programs for disease management and psychotherapeutic programs for stress management followed by a self-efficacy evaluation to confirm its effectiveness is desirable.
Work-related stress is another important source of stress in diabetes mellitus, particularly of the type 2 variety. A number of factors are involved in determining stress at workplace. These include work demands, support from colleagues and superiors, ability to change way and rate at which work is undertaken (known as decision latitude) amongst others. Those with high work demand and low decision latitude are said to be under “job strain”. The results of studies in this area are somewhat inconsistent with some studies not showing a significant relationship between diabetes and work-related stress. A systematic review and meta-analysis by Cosgrove et al.14 concluded that the hypothesis of direct relationship between work-related stress and T2DM could not be supported. However, the authors cautioned that the constituent studies of the meta-analysis had poor methodology and used variable statistical analyses making need for future studies in this area necessary. Many of the studies were cross-sectional, included no formal assessment of diabetic status and used self reports. Notably, the Whitehall II study15 which used a prospective design and a formal assessment of diabetic status concluded that psychosocial stress at work doubles the risk of type 2 diabetes in middle-aged women.
DIABETES AND STRESS: BIOLOGICAL ASPECTS
The debate surrounding the link between stress and diabetes seems to have settled over the past few years. A number of biological factors underlie this link. The cortisol theory and the sympathetic nervous system activation theory are the two most well-studied theories explaining these biological underpinnings.
The role of cortisol pathway in mediating the link between psychological stress and diabetes is best exemplified by studies on depression and diabetes. In melancholic depression, a corticotropin-releasing hormone (CRH) receptor hypofunction and dysfunctional glucocorticoid receptors in the hypothalamus have been hypothesized by some researchers to result in impaired normal feedback control.16 This results in an overdriven hypothalamic-pituitary-adrenal (HPA) axis with increased CRH and cortisol levels. A state of insulin resistance is thus created which when coupled with a hypothesized reduced insulin secretion may lead to T2DM. A contrasting version has been hypothesized in case of atypical depression.16 In atypical depression, the HPA axis is hypoactive and there is hypocortisolism. There may be a gain of function in the hypothalamic glucocorticoid receptors as well as in the CRH receptors resulting in this hypoactive picture. An associated gain of function in the β-cells of pancreas has also been hypothesized to result in increased insulin secretion. Despite this, there is insulin resistance possibly due to noncortisol mediated visceral obesity. This may be related to excessive food intake, particularly carbohydrates which are known to reduce insulin sensitivity. However, these theories await further empirical validation.
The activation of sympathetic nervous system plays an important role in insulin resistance, diabetes and metabolic syndrome.17 Animal experiments have demonstrated the role of neuropeptide Y (NPY) in the development of these disorders. The release of neuropeptide Y from sympathetic nerves results in visceral obesity and insulin resistance. The action on NPY2 receptors stimulated fat angiogenesis and proliferation of adipocytes in animal studies. However, the role of NPY in humans is yet to be established firmly. Those with obesity and diabetes also have higher muscle sympathetic nerve activity which further implicates the role of sympathetic nervous system. The activity increases further in those with other related disorders such as hypertension. Prolonged stress may lead to increased levels of circulating catecholamines, which in turn impair essential metabolic and physiologic functions.17
DIABETES MELLITUS AND PSYCHIATRIC COMORBIDITY
A discussion on psychological stress and diabetes would be incomplete without addressing psychiatric comorbidity. While stress is a broad term, diagnosable psychiatric illnesses have specific diagnostic criteria and threshold making their study more systematic.
Prevalence of diabetes has been found to be higher among individuals with psychotic as well as neurotic disorders. The rate of diabetes is 1.5–2 times higher among those with affective disorders and schizophrenia as compared to the general population. The following discussion, however, will be restricted primarily to neurotic disorders especially depression.
A meta-analysis consisting of 39 studies found the prevalence of depression in diabetes to be around 12%. Other large studies have also reported similar figures. Those with diabetes and depression tended more often to be younger females who were less educated, were smokers and had a longer duration of diabetes with more complications and poorer glycemic control when compared to those with only diabetes. Besides being more prevalent among those with diabetes, depression also tends to be either recurrent or chronic in these individuals. Up to 79% of those with depression and diabetes have been found to relapse within 5 years. Also, 63% of those with depression and diabetes had >2 years of significant depressive symptoms.1
The risk of diabetes is also higher among those with depression.1 Rotella et al.18 conducted a meta-analysis of 23 longitudinal studies with 19,977 cases of incident diabetes and a mean follow-up of around 8 years. They concluded that depression was a risk factor for incident diabetes, and the risk was over and above that due to antidepressants and being overweight. They also recommended that depression should be among the list of risk factors that indicate intensified screening for diabetes.
Depressive disorders and diabetes mellitus seem to share their biological underpinnings, at least in part. Incidentally, studies among individuals with depressive disorders have implicated various neurotransmitters and hormones including those from sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis. Co-occurring diabetes and depression could be the two final outcomes of shared biological mechanism. Also, it is possible that one leads to the other by acting on these intermediary mechanisms.
Effects of Depression on Various Diabetes Related Aspects
A number of studies have shown that patients with diabetes and depression report more symptoms than what the HbA1c levels or associated complications would suggest.19,20 A number of factors can explain these findings. Depression may be associated with abnormalities of descending pain pathways leading to more perceived pain and other symptoms. Also, chronic pain, such as that due to neuropathy, is a known risk factor for depression. Additionally, depression may promote a negative view of self leading to a more catastrophic view of one's current health status. Moreover, somatic symptoms may be the manifestation of depression itself as well.
Depression and anxiety have marked effects on the functioning of patients with diabetes. In fact, the impairment of functioning due to depression and anxiety can be greater than that due to diabetes related physical complications.19 A longitudinal study that surveyed over 4,000 patients showed that depression in diabetes resulted in a tenfold increase in likelihood of functional impairment.21 There was also a fourfold increase in inability to do household work as well as vocational work. Similarly, a decrease in activities of daily living has also been observed by other researchers, particularly in the elderly.22
Depression also markedly influences self-care and medication adherence in diabetes. A number of studies have established that patients with diabetes and depression have a lesser rate of medication adherence.22,23 They are also less likely to follow the preventative care procedures in comparison to those with diabetes without depression. Lifestyle modifications like healthy diet and exercise are also less likely to be followed by those with diabetes and depression. A meta-analysis of 25 studies24 concluded that the odds of nonadherence to medication regimen were three times higher in those with depression than those without it. Depression or anxiety may impair this aspect of diabetes care in a number of ways. Decreased energy, anhedonia and impaired cognitive functions all have obvious implications for diabetes care. Additionally, pessimistic views of future might lead the person to believe that there is no point in following these regimens. Also, noncompliance to medications might indicate underlying death wishes in the patient.
Depression also increases the risk for other cardiac risk factors. In a large longitudinal study,21 it was found that those with depression in addition to diabetes had two times more probability of having three or more cardiac risk factors. This is particularly important as the vast majority of deaths in diabetes are due to cardiovascular or cerebrovascular abnormalities.
Depression in diabetes also impacts the likelihood of emergence of diabetes related complications. A meta-analysis examining studies involving patients (total 5,374) with either type 1 or 2 diabetes over a 25-year-period concluded that there was significant and consistent association between the two.25 The association however may be bidirectional with more complications resulting in depression as well as vice versa. However, longitudinal studies have shown that the association with depression is not merely a consequence of complications. It has been demonstrated that comorbid depression increases the risk for diabetic complications.1 Studies in children and elderly have also reached similar conclusions.1
Finally, aforementioned factors also contribute to the markedly increased burden on the healthcare system among diabetic patients with comorbid and depression. The healthcare costs are increased significantly by as much as 70% according to some studies.1 Thus, treatment of depression would increase the healthcare burden and medical costs of the health system significantly.21
MANAGEMENT OF PSYCHOLOGICAL STRESS AND DEPRESSION IN DIABETES
Stress Management Training
Stress management training is an important aspect of treatment of diabetes. A number of studies have demonstrated and established its importance. Surwit et al.26 and Lammers et al.27 have shown the beneficial effects of relaxation training on glycemic control in type 2 diabetes. However, studies in type 1 diabetes have been less encouraging. Feinglos et al.28 found that there was no significant difference in glycemic control between those practicing relaxation training and those that did not in patients diagnosed with type 1 diabetes. Stenstrom et al.29 also studied the effects of stress management training in type 1 diabetes and found that although the effects on glycemic control were not significant, there was a significant improvement in mood, confidence and optimism. Notably, Robertson et al.30 found that positive emotional health may facilitate chronic self-care management and positive health outcomes.
Stress management training can be discussed under five headings as described below.31 This training method is based primarily on the principles of cognitive behavioral therapy (CBT).
This is the first step in stress management training. In order to manage stress, one needs to know first how one responds to various situations, specially the problematic ones. The information available from this step can then be used in subsequent steps to learn more adaptive ways of handling stress. This step essentially involves noting down in a systematic pattern how one deals with problematic situations. The patient is instructed to maintain a daily diary record of the same. Each instance is recorded under three headings: (i) antecedent, (ii) behavior and (iii) consequences (ABC charting) (Table 1). Antecedent means any trigger that the patient perceives as stressful.
It could be an external agent such as an interpersonal event or an internal agent like exacerbation of symptoms of a physical illness. The patient also records the severity of the perceived stress on a scale of 0–100 where “0” means not stressful at all and “100” means that the stress is equivalent to the most stressful event ever experienced by the patient. Behavior column is used to record the patient's response to the stressful trigger. It is recorded under the realms of thought, emotion, physiological responses and behavior. For example, let us consider the example of the patient seeing a colleague with whom he had a quarrel the previous day, walking up to him across the hall as an antecedent. The patient assigns a severity score to this situation. The thoughts could include statements such as “he will shout at me; he will physically hurt me”. The associated emotion may be that of intense fear which may be associated with physiological responses such as palpitations, sweating, tightening of muscles, etc. Alternatively, there may be associated emotion of anger. The behavioral response may be in the form of running away in case of fear or an angry verbal or physical confrontation in case anger was the associated emotion. The consequence would be recorded as something like “I remained disturbed and unable to do work for two hours. I felt disgusted with myself for being a coward. I eventually calmed down and got back to work.”
Self observation is important for various reasons. It enables patients to pay attention to an important aspect of themselves that they might have been ignoring. Since it is a systematic documentation of one's response to a situation, it enables one to clearly see where things are going wrong. It also enables one to draw comparisons between situations with which one copes well and with which one does not, providing an opportunity for individualized solutions.
This is the second step in stress management training. Central idea here is that if dysfunctional thoughts can be altered favorably, then positive emotional states and desirable behaviors can be enhanced. An analysis of the daily diary maintained in the self-observation phase gives us valuable information regarding such dysfunctional thoughts. For instance, in the example considered above, there was fear on seeing the colleague approaching. This was based on the underlying thoughts that the colleague would shout at him or physically hurt him. This was followed by patient running away and later feeling disgusted with himself that he was always such a coward. In this case, various dysfunctional thoughts can be identified. Initially, when he watched the colleague walking across, the patient assumed without considering alternatives that the colleague was going to be rude with him based on one previous instance of altercation the preceding day. It could very well have been possible that the colleague might have been coming toward him to apologize for the previous day's incident. Similarly, after running away, the patient labeled himself a coward based on this single instance although there could have been other instances where he did not behave in this manner.
Thus, after observing a dysfunctional thought, the patient is asked to challenge the same and replace it with more adaptive ones (Box 1).
Relaxation skills are very helpful in managing stress. When one is relaxed, there is an overall decrease in muscle tone and accompanying improvement in autonomic hyperactivity leading to beneficial effects. There are several techniques of relaxation training. These have been described briefly below.
- Progressive relaxation: It involves alternatively tensing and then releasing the tension and relaxing specific body parts. The entire body is covered over a series of sessions with each session devoted to a particular section of the body. The tensing followed by relaxing serves to demonstrate the difference between the two states so that the patients can learn to relax body parts effectively.
- Release only relaxation: It is similar to progressive relaxation except that the tension phase is omitted. Once the patients have discerned what is a relaxed state, they can practice release only relaxation.
- Cue-controlled relaxation: It involves coupling relaxation with a verbal cue such as the word “relax”. The individual in a comfortable position breathes in and out relaxing oneself with each breath. He inhales with the words “breathe in” and exhales with the words “relax” simultaneously releasing tension in the muscles and relaxing. Once this association is strong, it enables one to relax in any situation by using the words “breathe in and relax”.
- Differential relaxation: It involves relaxing the muscles not in use while contracting those in use. It is practiced initially in simple situations and then progress to more complex ones. For instance, while writing sitting on a chair, the muscles of the hand need to be contracted whereas other muscle groups can be relaxed. This aids one to practice relaxation techniques in real-world stressful situations where one is engaging in some activity.
- Rapid relaxation: It involves patients shortening the duration needed to relax to 20–30 seconds. Patients take 2–3 deep breaths and relax along with expiration. This could be repeated several times during the day.
Application training involves using these techniques in a real-life stressful scenario. The patient engages in relaxation before entering the stressful situation and stays so for the necessary duration, thus coping effectively with the stressful situation.
The relaxation techniques have been summarized in Table 2.
Patients under stress often may not have a structure to their routines. Although, they may be facing situations that they perceive as challenging, they may not be able to mount an adaptive response due to poor management of time.
Initially, the patient is asked to record how he spends his time noting the amount of time spent on various activities to obtain a baseline. Then, the activities a patient involves in are prioritized. The activities are considered under the headings of importance and urgency to enable suitable planning. Then, the current goals are established depending on the patient's current situation. A suitable timetable is then made based on the goals that need to be achieved in the time frame, after considering their priority and urgency. The timetable charted out should not be too rigid or too lax. Making it too rigid would result in unavoidable failure and its accompanying negative emotional consequences, while too lax does not serve the purpose why the timetable was made in the first place. The making of timetable must be accompanied by a commitment from the patient's side that he or she would make best efforts to enforce it. Time management is summarized in Box 2.
Problem solving refers to the technique of dealing effectively with a problem situation by systematic analysis of the problem and possible solutions.
Stress impairs one's capability to deal with a problem which in turn further perpetuates the stress. Thus, problem solving is an important component of stress management training.
The first step in problem solving is defining the problem and its various attributes. Once the problem is clearly identified, then one generates the various possible alternatives to solve the problem. At this stage, no criticism of each option is allowed and all possible alternatives are listed without considering their reasonableness. There are several ways of generating alternatives. These include considering what one has done in the past in a similar situation, what other people have done in a similar situation, and new and innovative candidate solutions to the problem that have not been tried before. Once this has been done, one looks for the best possible solution. In deciding the best possible solution, one considers various parameters. This includes amongst others, the likelihood of a positive or desired outcome with an option and the feasibility of such an option. The final step of course is the successful implementation of the decided upon solution. Problem solving is summarized in Box 3.
Stress management training and its components are summarized in Figure 3.
PSYCHOLOGICAL INTERVENTIONS IN ADOLESCENTS AND YOUNG ADULTS WITH DIABETES
Several studies have assessed the effectiveness of various psychological interventions in adolescents and young adults with diabetes. A recent systematic review32 assessed studies published from 1979–2010 and included 25 studies involving adolescents and young adults with chronic illnesses. Thirteen of these studies included subjects suffering from diabetes. The review concluded that skill-based interventions delivered over multiple sessions may yield the most positive results.
Skill-based programs involve practical training in adaptive coping strategies to deal with both current as well as future stressors. They may or may not involve a parent. Communication strategies are especially important in such training and enhance its effectiveness. These programs need to be administered by a counselor, psychologist or somebody with comparable training and in-session practice and homework also add to the effectiveness. Length of contact appears to be crucial for effectiveness of these interventions with a minimum recommended duration of 3 months.32 Booster sessions may be conducted to enhance as well as prolong the beneficial effects of these interventions. Some researchers have attempted to deliver such interventions via the internet as well widening the reach.33
TREATMENT OF DEPRESSION IN DIABETES
A meta-analysis of 14 randomized controlled trials with a total of 1,724 patients34 concluded that attention to depression among those with diabetes is a necessary step but improvement needed simultaneous attention to both conditions. The meta-analysis included studies evaluating pharmacotherapy, psychotherapy as well as collaborative care of depression in patients with type 1 and T2DM. Studies have shown that mere treatment of acute phase of depression with antidepressants has inconsistent effects on glycemic control whereas sustained treatment including a maintenance phase leads to consistent improvement in the glycemic control.1 A recent Cochrane systematic review35 concluded that both psychological and pharmacological interventions improved depression related outcomes in diabetes. The effect was clinically significant and moderate. Glycemic control improved moderately in case of pharmacological interventions whereas it was inconclusive in case of psychological interventions. A need for high-quality studies in the future was recommended by the authors.
Among the antidepressants, tricyclics are to be usually avoided due to concerns of weight gain. Selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors are the preferred agents. For those with sexual dysfunction, bupropion may be preferred and in those with neuropathy, venlafaxine, duloxetine or bupropion may be considered.
PSYCHOSOCIAL MANAGEMENT OF DIABETES IN INDIA: NATIONAL RECOMMENDATIONS
For a detailed account of national recommendations for India, the reader is referred to the article by Kalra et al.36 Here, we describe briefly those that are strongly recommended and have the highest level of evidence (evidence level 1, recommendation grade A).
The healthcare professionals should have training in psychosocial interventions for diabetes mellitus. They should explain to the patient the link between various psychosocial stressors and diabetes related parameters. Cognitive behavioral therapy is the recommended modality of intervention of which Indian adaptations (e.g., Karnal model) are available. Behavioral Family Systems Therapy-Diabetes (BFST-D) is also a recommended form of therapy. Psychological interventions are recommended both for adults as well as child and adolescents and should be individualized. Problem based approach should be used along with diabetes self-management education. Validated diabetes-specific psychological instruments are available and should be used wherever possible and appropriate. Patients should be encouraged to participate in patient empowerment programs. One should also strive to improve community awareness regarding diabetes mellitus.
SUMMARY AND CONCLUSION
Psychological stress and depression are important aspects that one needs to consider while treating an individual with diabetes. Diabetes itself can be envisioned in terms of psychosocial stages where the risk of psychological problems is higher. The person's personality characteristics, disease characteristics, and family and work environment are among the important factors influencing stress levels in a given person. A number of biological pathways have been postulated to explain the link between the two with the cortisol pathway and sympathetic activation pathway being the most studied ones. Higher psychological stress and depression predict a poorer course for diabetes with increase in symptoms, complications, health costs, mortality and poorer self-care. Both pharmacological and nonpharmacological interventions are available and appear effective in treatment of depression and to manage stress in diabetes. Such interventions may play a vital role in improving the course and outcome as well as quality of life of individual with diabetes.
- Katon W, Ciechanowski P. Diabetes: psychosocial issues and psychiatric disorders. In: Sadock BJ, Sadock VA, Ruiz P (Eds). Comprehensive Textbook of Psychiatry, 9th edition. Lippincott Williams and Wilkins; Philadelphia: 2009. pp. 2519-38.
- Snoek FJ, Skinner TC. Psychological counseling in problematic diabetes: does it help? Diabet Med. 2002;19(4):265–73.
- Ruggiero L, Glasgow RE, Dryfoos JM, Rossi JS, Prochaska JO, Orleans CT, et al. Diabetes self-management. Self-reported recommendations and patterns in a large population. Diabetes Care. 1997;20(4):568–76.
- Jacobson AM, Weinger K. Psychosocial complications of diabetes. In: Leahy JL, Clark NG, Cefalu WT (Eds). Medical Management of Diabetes Mellitus, 1st edition. Marcel Dekker Inc; New York: 2000 p. 560.
- Cohen S, Kessler RC, Gordon LU. Measuring stress: A Guide for Health and Social Scientists, 1st edition. Oxford University Press; New York: 1997.
- Taylor SE, Aspinwall LG. Mediating and moderating processes in psychological stress: appraisal, coping, resistance, and vulnerability. In: Kaplan HB (Ed). Psychosocial Stress: Perspectives on Structure, Theory, Life-Course and Methods, 1st edition. Academic Press; San Diego: 1996. pp. 71-110.
- Skinner TC, Bruce DG, Davis TM, Davis WA. Personality traits, self-care behaviours and glycaemic control in type 2 diabetes: the Fremantle Diabetes Study Phase II. Diabet Med. 2014;31(4):487–92.
- Jokela M, Elovainio M, Nyberg ST, Tabák AG, Hintsa T, Batty GD, et al. Personality and risk of diabetes in adults: pooled analysis of 5 cohort studies. Health Psychol. 2014;33(12): 1618–21.
- Anderson BJ. Family conflict and diabetes management in youth: clinical lessons from child development and diabetes research. Diabetes Spectr. 2004;17:22–6.
- Laffel LM, Connell A, Vangsness L, Goebel-Fabbri A, Mansfeld A, Anderson B. General quality of life in youth with type 1 diabetes: relationship to patient management and diabetes-specific family conflict. Diabetes Care. 2003;26(11):3067–73.
- Duke DC, Geffken GR, Lewin AB, Williams LB, Storch EA, Silverstein J. Glycemic control in youth with type 1 diabetes: family predictors and mediators. J Pediatr Psychol. 2008;33(7):719–27.
- Lewin AB, Heidgerken AD, Geffken GR, Williams LB, Storch EA, Gelfand KM, et al. The relation between family factors and metabolic control: the role of diabetes adherence. J Pediatr Psychol. 2006;31(2):174–83.
- Jaser SS, Grey M. A pilot study of observed parenting and adjustment in adolescents with type 1 diabetes and their mothers. J Pediatr Psychol. 2010;35(7):738–47.
- Cosgrove MP, Sargeant LA, Caleyachetty R, Griffin SJ. Work-related stress and type 2 diabetes: systematic review and meta-analysis. Occup Med (Lond). 2012;62(3):167–73.
- Heraclides A, Chandola T, Witte DR, Brunner EJ. Psychosocial stress at work doubles the risk of type 2 diabetes in middle-aged women: evidence from the Whitehall II study. Diabetes Care. 2009;32(12):2230–5.
- Gragnoli C. Depression and type 2 diabetes: cortisol pathway implication and investigational needs. J Cell Physiol. 2012;227(6):2318–22.
- Lambert EA, Lambert GW. Stress and its role in sympathetic nervous system activation in hypertension and the metabolic syndrome. Lambert Curr Hypertens Rep. 2011;13(3):244–8.
- Rotella F, Mannucci E. Depression as a risk factor for diabetes: a meta-analysis of longitudinal studies. J Clin Psychiatry. 2013;74(1):31–7.
- Ludman EJ, Katon W, Russo J, Von Korff M, Simon G, Ciechanowski P, et al. Depression and diabetes symptom burden. Gen Hosp Psychiatry. 2004;26(6):430–6.
- Katon W, Lin EH, Kroenke K. The association of depression and anxiety with medical symptom burden in patients with chronic medical illness. Gen Hosp Psychiatry. 2007;29(2):147–55.
- Katon WJ, Von Korff M, Lin EH, Simon GE, Ludman E, Russo J, et al. The Pathways study: a randomized trial of collaborative care in patients with diabetes and depression. Arch Gen Psychiatry. 2004;61(10):1042–9.
- Black SA, Markides KS, Ray LA. Depression predicts increased incidence of adverse health outcomes in older Mexican Americans with type 2 diabetes. Diabetes Care. 2003;26(10): 2822–8.
- Lin EH, Katon W, Von Korff M, Rutter C, Simon GE, Oliver M, et al. Relationship of depression and diabetes self-care, medication adherence, and preventive care. Diabetes Care. 2004;27(9):2154–64.
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- Surwit RS, Feinglos MN. The effects of relaxation on glucose tolerance in non-insulin-dependent diabetes mellitus. Diabetes Care. 1983;6(2):176–9.
- Lammers CA, Naliboff BD, Straatmeyer AJ. The effects of progressive relaxation on stress and diabetic control. Behav Res Ther. 1984;22(6):641–50.
- Feinglos MN, Hastedt P, Surwit RS. Effects of relaxation therapy on patients with type 1 diabetes mellitus. Diabetes Care. 1987;10(1):72–5.
- Stenstrom U, Goth A, Carlsson C, Andersson PO. Stress management training as related to glycemic control and mood in adults with type 1 diabetes mellitus. Diabetes Res Clin Pract. 2003;60(3):147–52.
- Robertson SM, Stanley MA, Cully JA, Naik AD. Positive emotional health and diabetes care: concepts, measurement, and clinical implications. Psychosomatics. 2012;53(1):1–12.
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- Whittemore R, Jaser SS, Jeon S, Liberti L, Delamater A, Murphy K, et al. An internet coping skills training program for youth with type 1 diabetes: six-month outcomes. Nurs Res. 2012;61(6):395–404.
- van der Feltz-Cornelis CM, Nuyen J, Stoop C, Chan J, Jacobson AM, Katon W, et al. Effect of interventions for major depressive disorder and significant depressive symptoms in patients with diabetes mellitus: a systematic review and meta-analysis. Gen Hosp Psychiatry. 2010;32(4):380–95.
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