Summary of reviewed randomized controlled trials.
This chapter explores the efficacy of psychotherapeutic interventions for patients with type 2 diabetes mellitus (T2DM). This condition can lead to serious adverse health outcomes (e.g., cardiovascular disease, blindness, loss of limbs, etc.). Medical interventions alone are often not sufficient to manage the disease. Psychotherapy can promote behavioral change that improves medication adherence, dietary choices, exercise, stress, and other variables that affect blood sugar levels. The current chapter summarizes the trends in recent research for psychotherapeutic interventions for the management of T2DM. The results from 16 randomized controlled trials on cognitive-behavioral therapy, motivational interviewing, counseling, and mindfulness-based therapies are discussed. These interventions varied in length (3 to 18 months) and were conducted in many geographic regions (e.g., Australia, Netherlands, Saudi Arabia, Thailand, and more). Changes in biological health outcomes (i.e., HbA1c levels) were the primary focus of this chapter, but diabetes-related behavioral changes (e.g., diet and exercise) and psychological variables (e.g., stress, depression, and well-being) are also discussed. This chapter highlights that recent research has provided the most support for mindfulness-based therapies for improving blood sugar levels in patients with T2DM.
- Type 2 diabetes mellitus
Diabetes mellitus is a condition marked by an inability to produce or properly use insulin, a hormone that allows cells to use glucose for energy . Approximately 3 million Canadians, or 8% of the general population, are living with diabetes, with the prevalence increasing with age . The condition usually develops in middle aged or older adults, and men are slightly more likely to be diagnosed with this condition (8.7%) than are women (7.6%) . There are two types of diabetes mellitus: type 1, where the body cannot produce a sufficient amount of insulin, and type 2, where the body cannot use the insulin it produces effectively, resulting in high blood sugar levels . Accordingly, blood glucose levels are the most reliable physiological marker by which to diagnose diabetes mellitus  and are also used to monitor patients’ management of their condition. The main criterion for a diagnosis of diabetes mellitus is a hemoglobin A1c [HbA1c] level above 6.4%, indicating above-average blood sugar levels, for the past 2–3 months. Interventions that produce lower HbA1c levels indicate efficacy at improving patient self-management of their diabetes mellitus. If left untreated or if poorly managed, diabetes mellitus can lead to serious health conditions such as heart disease and stroke, blindness, nerve damage, and loss of limbs .
About 90% of people with diabetes mellitus have type 2 (T2DM). This is a chronic disease, which must be carefully managed on an ongoing basis by the patient and/or their caregivers. The biopsychosocial approach combines the use of medication and insulin with self-management behaviors for the purpose of regulating blood glucose levels. Lifestyle changes that are generally recommended for people at higher risk of diabetes and those who are newly diagnosed include sufficient moderate to high intensity exercise, and dietary considerations such as increased intake of fiber and reduced intake of fats (especially saturated fat). As well, overweight individuals are advised to lose weight gradually to achieve a body mass index in the healthy range. Health care professionals working with patients with T2DM aim to teach and encourage appropriate eating habits and physical activity to help patients achieve better glycemic control. However, implementing and adhering to these lifestyle changes is often difficult. Many individuals with T2DM do not adhere to the recommended nutrition and physical activity guidelines. Specifically, many patients exceed the recommended fat and sodium intake, and do not consume enough grains, dairy, fruits and vegetables . Stress is also recognized as a variable that can exacerbate T2DM. Stress triggers the release of hormones that produce a surge in blood glucose levels. For this reason, stress management is considered to be part of a biopsychosocial approach to the management of T2DM. Due to the prevalence and manageability of this type of diabetes mellitus through lifestyle modifications alone, this chapter will focus solely on T2DM.
In addition to pharmacological interventions, various psychotherapeutic interventions are used and have been studied to help people with T2DM achieve better glycemic control. In theory, psychotherapy can promote behavioral changes that would improve medication adherence, dietary choices, exercise, stress levels, and other variables that affect blood sugar levels. Within this chapter, we review various psychotherapeutic interventions that are commonly used for the management of T2DM, including cognitive-behavioral therapy, motivational interviewing, counseling, and mindfulness-based therapies. This chapter explores the trends in recent research to understand the evidence base for various psychotherapeutic interventions in the management of T2DM. Change in HbA1c level is the primary focus of this chapter, since HbA1c is commonly measured and is the most objective and standardized outcome measure across studies. However, trends in diabetes-related behavioral changes (e.g., diet and exercise) and psychological variables (e.g., coping, stress, depression, and well-being) are also discussed.
2. Psychotherapeutic interventions for type 2 diabetes mellitus
Previous review papers have demonstrated that psychotherapeutic interventions in general are effective at improving health outcomes for individuals with T2DM. A 2004 meta-analysis of 12 randomized control trials (RCT) of psychological interventions (i.e., cognitive behavior therapy, counseling, or psychodynamic therapy) found lower HbA1c levels and psychological distress compared to different control groups (i.e., treatment as usual, an education group, attentional control, or waitlist control) . There was no difference between treatment groups on weight gain and blood glucose concentration, suggesting that there was no clearly superior psychological intervention for the management of T2DM. A 2013 systematic review similarly concluded that psychotherapy is effective in supporting healthy coping among individuals with diabetes mellitus . More recently, a 2020 meta-analysis of 70 RCTs found that psychological interventions, such as cognitive behavioral therapy, self-help materials, and counseling, were generally effective in reducing HbA1c levels over and above usual care .
These research findings cited above support the general use of psychotherapeutic interventions in the management of diabetes mellitus. However, it would be helpful to know whether and how specific interventions can enhance care for patients with T2DM so as to assist with treatment planning. In this chapter we analyze the recent literature on the efficacy of psychotherapeutic interventions for the care of T2DM. There have been 16 relevant RCTs published within the past 8 years (see Appendix A for details of the search strategy), which represent the most up-to-date published scientific findings on the topic. These studies and time period were deemed to give a valid snapshot of the recent literature. The results of specific studies are discussed, and we summarize the most noteworthy findings within each type of psychotherapeutic intervention. The effects of specific interventions on various outcomes relevant to patients with T2DM are discussed in detail. See Table 1 for a summary of the reviewed studies.
|Author (Year)||N||Age||Sex (M, F)||Ethnicity||Country||Intervention||Duration||Outcome||p-value|
|Abu-Saad, Murad, Barid, Olmer, Ziv, Younis-Zeidan, & Kalter- Leibovici (2019)||50||53||21,29||Arab||Israel||Interactive lifestyle assessment, counseling and education (motivational interviewing) Standard lifestyle advice||6 months|
|Diabetes Knowledge – 3 months||.023|
|Alanzi, Alanzi, Istepan i-an, & Philip (2018)||20||NA||15,5||NA||Saudi Arabia||Mobile CBT||6 months|
|Conventional diabetes treatment||HbA1c||.002|
|Diabetes Knowledge Test||.004|
|Armani, Vahdani, Noorbala, Nejatisafa, Arbabi, Zenoozian & Nakhjavani (2018)||60||56||11, 49,||NA||Iran||Mindfulness-based stress reduction||3 months|
|Fasting blood sugar||.001|
|Overall mental health||.001|
|Chee, Gilcha-ran Singh, Hamdy, Mechanick, Lee, Barua, Ali & Hussein (2017)||230||55||85, 145||Indian (58%)||Malaysia||Motivational interviewing (Trans-cultural diabetes-specific nutrition algorithm+MI)||6 months|
|6 month follow-up|
|Malaysian (14%)||HbA1c||< .001|
|Weight loss||< .001|
|Body Mass Index||< .001|
|Conventional counselling (Trans-cultural diabetes-specific nutrition algorithm+CC)||Waist circumference||< .001|
|Body fat||< .001|
|Fasting plasma glucose||.027|
|Systolic blood pressure||.003|
|Diastolic blood pressure||.013|
|Triglyceride high sensitivity||.855|
|Weight loss||< .001|
|Dobler, Herbeck Belnap, Pollmann, Fairn, Raspe & Mittag (2018)||199||52||140, 59||NA||Germany||Telephone follow-up motivational interviewing||12 months|
|Body mass index||.218|
|Friis, Johnson, Cutfield, & Consedine (2016)||63||43||20, 43||New Zealand||New Zealand||Mindful self-compassion program||3 months|
|Asian (8%)||Diabetes Distress||.05|
|Other Pacific (5%)|
|Other European (13%)|
|Gainey, Himathongkam, Tanaka & Suksom (2016)||23||60||4, 19||NA||Thailand||Traditional walking||3 months|
|Fasting blood glucose||>.05|
|Holmen, Torbjornsen, Wahl, Jenum, Smastuen, Arsand, & Ribu (2014)||151||57||89, 62||NA||Norway||Few Touch Application (FTA)||12 months|
|HbA1c (FTA x control)||.42|
|Few Touch Application—Health Counseling (FTA-HC)→Motivational interviewing Control|
|HbA1c (FTA-HC x control)||.97|
|Self-management skill and technique acquisition (FTA x control)||.79|
|Self-management skill and technique acquisition (FTA-HC x control)||.04|
|Health service navigation (FTA x control)||.06|
|Health service navigation (FTA-HC x control)||.97|
|Jansink, Braspenning, Keizer, van der Weijden, Elwyn & Grol (2013)||521||64||285, 236||NA||Netherlands||Nurse motivational interviewing program||14 months|
|Systolic blood pressure||.279|
|Usual care||Diastolic blood pressure||.294|
|Body mass index||.198|
|Juul, Maindal, Zoffmann, Frydenberg & Sandbaek (2014)||4034||60||2279, 1755||NA||Denmark||Nurse motivational interviewing program||18 months|
|Total cholesterol (mmol/l)||.02|
|Total cholesterol ≥5 mmol/l||.07|
|Medication –controlled motivation||1.00|
|Medication –autonomous motivation||1.00|
|Diet and physical activity – controlled motivation||0.70|
|Diet and physical activity –autonomous motivation||0.98|
|Perceived Competence for Diabetes Scale||0.97|
|Mohamed, Al-Lenjawi, Amuna, Zotor, & Elmahdi (2013)||430||53.5||NA||Arab||Qatar||Culturally sensitive structured education program||12 months|
|Problem Areas in Diabetes||.31|
|Mental component of the impact of health on daily living (SF-12)||.15|
|Fasting plasma glucose||.022|
|Systolic blood pressure||.631|
|Diastolic blood pressure||.421|
|Body mass index||.001|
|Pearson, Wills, Woods, & Warnecke (2018)||67||59||36, 31||NA||Australia||Mindfulness practice||3 months|
|Monitoring Blood Glucose||. 06|
|Systolic blood pressure||.78|
|Diastolic blood pressure||. 28|
|Problem Areas in Diabetes||.78|
|Tovote, Fleer, Snippe, Peeters, Emmelkamp, Sanderman…Schroevers (2014)||94||53||48, 46||NA||Netherland||Mindfulness-based cognitive therapy (MBCT)||3 months|
|Cognitive behaviour therapy (CBT)|
|Depression -BDI-II (MBCT x Control)||.004|
|Depression -BDI-II (CBT x Control)||.001|
|Depression -HAM-D7 (MBCT x Control)||.001|
|Depression -HAM-D7 (CBT x Control)||.001|
|Well-being -WHO-5 (MBCT x Control)||.001|
|Well-being -WHO-5 (CBT x Control)||.001|
|Anxiety - GAD-7 (MBCT x Control)||.004|
|Anxiety - GAD-7 (CBT x Control)||.01|
|Diabetes Distress (MBCT x Control)||.02|
|Diabetes Distress (CBT x Control)||.04|
|van Son, Nyklicek, Pop, Blonk, Erdtsieck, Spooren, …Pouwer (2013)||139||56.5||70, 69||NA||Netherland||Mindfulness-based cognitive therapy||3 months|
|Physical Health Status||.03|
|Perceived Stress Scale||.001|
|Mental Health Status||.01|
|van Son, Nyklicek, Pop, Blonk, Erdtsieck, & Pouwer (2014)||139||56.5||70, 69||NA||Netherland||Mindfulness-based cognitive therapy||6 months|
|Physical Health Status||.034|
|Mental Health Status||.001|
|Varming, Rasmussen, Husted, Olesen, Grønnegaard, & Willaing, (2019)||97||64.3||64, 33||Danish||Denmark||Empowerment, motivation, and medical adherence (EMMA)||3.5 months|
|6-month follow up|
|Body mass index||>.05|
|Systolic blood pressure||>.05|
|Diastolic blood pressure||>.05|
|Problem areas in diabetes||>.05|
|Diabetes self-care activities||>.05|
|Body mass index||>.05|
|Systolic blood pressure||>.05|
|Diastolic blood pressure||>.05|
|Problem areas in diabetes||>.05|
|Diabetes self-care activities||>.05|
2.1 Cognitive-behavioral therapy
Cognitive-behavioral therapy (CBT) is an umbrella term that encompasses various cognitive and behavioral techniques to identify and transform negative thinking patterns. CBT has been used to promote behavioral change in patients with diabetes mellitus . A goal of CBT is to help individuals understand barriers to their own diabetes mellitus self-management and to provide them with the skills necessary to cope with these barriers. For example, a patient with diabetes mellitus may think, “I have a terrible chronic condition and there is nothing I can do about it.” This type of cognition can lead to poor treatment adherence, low confidence, and/or high levels of stress. Within a CBT protocol, the therapist helps the patient to identify thinking errors or “cognitive distortions” (e.g., anticipating the worst outcome, focusing on the negative, and thinking in all-or-nothing terms) and to use strategies to challenge these beliefs (e.g., “what evidence is there for and against this thought?”). In addition to developing more balanced or rational thoughts, the therapist and the patient can also work on behavioral changes. They may engage in gradual exposure to challenging activities (e.g., walking for 5 minutes a day, then 10 minutes, then 20 minutes, until they can walk for one hour) or behavioral experiments (e.g., writing down how they feel before and after taking medication in order to help identify that anticipatory anxiety is often worse than any discomfort they feel during or after the avoided task). In CBT, patients receive emotional and psychological support while learning strategies to overcome avoidance and to adhere to their medication, dietary intake, and physical activity goals. CBT for the management of T2DM can be done in weekly individual or group sessions, and is traditionally done in-person with a therapist and over the span of several weeks to months.
For many years, CBT was the most commonly investigated form of psychotherapy for T2DM (for example, see [4, 5, 6]) and results confirmed its efficacy in increasing positive outcomes. In recent years, the literature has shifted away from investigating CBT in its traditional application. Instead, new research has begun to examine CBT in alternative delivery formats in an effort to boost accessibility. For instance, a 6-month web-based CBT intervention was found to be more effective than a control group in lowering HbA1c levels (
2.2 Motivational interviewing
Motivational interviewing (MI) is a collaborative and goal-oriented therapy that focuses on resolving ambivalence toward change . Suggestions or instructions for diabetes mellitus self-management may be met with resistance and non-compliance by patients. MI counters these responses by promoting self-efficacy. The therapist helps the patient to determine what is important to their own well-being and how to achieve that goal . For example, a therapist may explore what the patient likes and does not like about their current behaviors to determine the costs and benefits of behavior change. By putting the patient in the ‘driver’s seat’, intrinsic motivation is developed (e.g., “I will change my diet and exercise because I want to live a long and healthy life”). The therapeutic alliance is seen as fundamental to facilitating positive behavior change. From this starting point, the therapist and patient can work together to set an agenda for items they would like to change (e.g., medication, diet, exercise, and regular monitoring of blood sugar levels) and check in frequently about the patient’s perceived importance and confidence regarding the target behavior .
Although MI has garnered a lot of research interest, the results of recent studies examining its utility in the management of T2DM have been mixed. In support of this intervention in the care of T2DM, Chee and colleagues (2017) found that patients who received MI for 6 months, in addition to diet and exercise planning, reported greater reductions in HbA1c (
Recent findings for MI in the management of T2DM are also mixed when MI examined in alternative delivery formats. A 12-month telephone-based delivery of MI in Germany was found to reduce patients’ HbA1c levels to a greater extent than usual care (i.e., informational pamphlets;
Another category of psychological interventions for T2DM involves counseling interventions which tend to provide non-specific support for diabetes mellitus management. Counseling typically promotes self-awareness and self-determination which, in the context of diabetes mellitus, can aid in improving self-management behaviors . Counseling can also provide emotional and psychological support to individuals who are dealing with the stress of living with a chronic disease. In other words, although behavior change is not the focus of counseling interventions, they may, in theory, be helpful for reducing stress and increasing adherence among patients.
RCTs of counseling interventions for T2DM are scarce [4, 5, 6], but there have been two recent studies on this modality. One study examined a culturally sensitive 12-month counseling program for T2DM patients in Qatar (i.e., using Arabic language and referencing culturally specific food habits and health beliefs). Within this program, patients were provided with information about diabetes and related complications, how to incorporate a healthy lifestyle and eating habits, the benefits of exercise, and how to use counseling techniques at home. The researchers found that this program led to significant reductions in patients’ HbA1c levels (
Based on these findings, counseling may have benefits for improving HbA1c levels in specific cultural contexts, but these therapies may have to be long-term (one year or longer) and follow a structured format to be beneficial for glycemic control.
2.4 Mindfulness-based therapies
Mindfulness-based therapies teach meditative practices and promote a non-judgmental awareness of the present moment, including noticing thoughts, emotions, and bodily sensations. In the context of T2DM, noticing negative diabetes-related thoughts can help promote passive observation of the experience and allow the individual to be present in their everyday life without an unhelpful behavioral reaction. For example, noticing internal hunger or satiety cues can influence dietary choices and help patients regulate blood sugar levels. Mindfulness can, in theory, help patients become better attuned to their physiological state, including blood sugar levels. Or a patient who experiences anxiety about increasing their physical activity may learn to nonjudgmentally notice their anxious thoughts and urges to avoid exercise, but intentionally choose to exercise nonetheless. Regular mindfulness practice trains the mind to be less reactive and more intentional in one’s choices and experiences.
Mindfulness interventions have increased in popularity in the past decade and there have been a number of recent RCTs that indicate the applicability of mindfulness-based therapies for the treatment of diabetes mellitus. The outcomes are mixed in regard to changes in HbA1c levels. In support of the efficacy of mindfulness programs, an 8-week mindfulness-based stress reduction program in Iran was found to improve HbA1c levels (
A relatively recent variation of mindfulness therapy, mindfulness-based cognitive therapy, involves training patients in both meditation and cognitive therapy (i.e., identifying and challenging cognitive distortions). A series of studies in the Netherlands were recently conducted to investigate the effects of this intervention on the care of patients with T2DM, but none showed any benefit for HbA1c levels. For instance, although van Son and colleagues [24, 25] found improvements in self-reported stress (
T2DM is a serious disease with significant morbidity which, if poorly managed, can lead to short- and long-term complications including cardiovascular disease, blindness, nerve damage, and loss of limbs . There has been interest among researchers to examine whether psychotherapeutic interventions aimed at changing thoughts, feelings, and/or behaviors among patients with T2DM have any significant benefit. Recent randomized controlled trials suggest that psychotherapy for T2DM may be an effective treatment option for certain outcomes, but that not all therapies have an evidence base for use with patients with T2DM.
Research from the past 8 years has provided the most support for mindfulness-based therapies at improving health outcomes for patients with T2DM. Numerous studies with different samples have demonstrated statistically significant reductions in HbA1c levels and fasting blood sugar, as well as improvements in psychological variables such as depression, anxiety, stress, diabetes-related distress, and overall mental health. These findings were demonstrated in various geographical regions (including Iran, New Zealand, and Australia) among middle-aged (average age ranged from 23 to 59 years old) men (
While research interest in traditional-delivery CBT has declined in recent years, one recent study expanded upon existing literature to demonstrate the effectiveness of CBT in a web-based format in diabetic patients from Saudi Arabia. This program improved HbA1c levels, as well as diabetes mellitus knowledge and self-efficacy, to a greater extent than the control group. The research results are more divided for MI and counseling interventions. In regard to the former, MI was typically found to be as effective as standard care on HbA1c levels and diabetes-related behaviors such as diet and physical activity in patients from Malaysia and parts of Europe (average ages 55 to 64 years old). However, when delivered in a telephone- or web-based format, MI had the added benefits of improving diabetes-related behaviors, such as dietary changes and physical activity, as well as psychological variables, including lowering depression and increasing well-being and diabetes-related knowledge. Notably, this was true in both men and women from diverse backgrounds (i.e., Arab and German). Recent findings for counseling intervention have been mixed whereby culture-specific counseling appears to be more effective at reducing HbA1c levels than informational booklets for middle-aged (
Commonly used psychotherapeutic interventions, such as mindfulness-based therapies and CBT, have empirical support in recent studies for use in the management of T2DM. This provides an evidence base for the widespread implementation of these treatments by healthcare professionals in their care of patients with T2DM. Training in both of these psychotherapy approaches for health professionals is widely available through professional development workshops or training manuals, and many workshops have been offered remotely during the COVID-19 pandemic. In addition, the recent promising findings from a study of self-directed mindfulness therapy suggests that healthcare professionals can recommend these programs to patients to pursue as a self-help resource, which reduces the potential obstacles of cost and geographic accessibility. Additional research is necessary to understand the efficacy of counseling and alternative-format CBT before practitioners should recommend these interventions in the management of T2DM.
This chapter reveals that psychotherapeutic interventions are an appropriate treatment modality for patients with T2DM and some have support from recent studies in improving health outcomes. These interventions extend beyond treating the physiological concerns of this disorder and can address other psychosocial variables, such as thoughts, feelings, and behaviors related to diabetes mellitus care. As such, not only did HbA1c levels improve in a number of treatments, research has supported changes in diet, physical activity, diabetes-related knowledge, and, in some cases, mood. There are no known negative effects of psychotherapeutic interventions on the health or well-being of patients with T2DM. The evidence for these interventions should be considered in regard to the sample population and size, comparison group, length of intervention, and geographic region.
There are still many gaps in the literature regarding which groups of individuals benefit the most from psychotherapy for T2DM and from which approach. Future research should continue to explore psychotherapeutic interventions especially in the areas of counseling and new delivery formats of CBT to expand treatment options. Of note, a recent RCT of Acceptance and Commitment Therapy for patients with T2DM has demonstrated preliminary success in improving HbA1c levels compared to education alone , but more research is needed on this intervention strategy before drawing generalized conclusions. In addition, more attention in future research studies needs to be paid to how different types of patients respond to psychotherapy and whether variables such as age, sex, and ethnicity interact with intervention type to produce different outcomes. Across all psychotherapeutic treatment modalities under investigation for use in the management of T2DM, treatment matching research is warranted to determine which patients may be able to benefit from modified, more accessible and cost-effective (self-help, web-based) formats. With that more targeted research in future research, healthcare professionals can feel even more confident implementing some therapies, such as mindfulness-based therapies, CBT, and some formats of MI, to promote better glycemic control and psychological well-being in their patients with T2DM.
Psychological interventions can lower HbA1c levels, improve psychological distress, and support healthy coping among patients with T2DM. There is recent and reliable research support for mindfulness-based therapies at improving HbA1c levels, blood sugar, and psychosocial variables. Results are promising, but more research is needed on the efficacy of longer-term culture-sensitive counseling as well as alternative delivery formats of cognitive-behavioral therapy on health outcomes among patients with T2DM.
Dr. Joel Katz is supported by a Canadian Institutes of Health Research Canada Research Chair in Health Psychology. Thank you to Susan Zahir for help with tables and revisions.
Conflict of interest
The authors have no conflicts of interest to declare.
To identify relevant studies, the authors used the same search terms as two previously published systematic reviews of psychotherapy for T2DM [4, 5]. The search was conducted by pairing relevant search terms, including “psychotherapy”, “cognitive-behavioral therapy”, “motivational interviewing”, “counseling”, “supportive therapy”, and “mindfulness-based therapy”, with “type 2 diabetes” and “randomized controlled trial” on PsycINFO, PubMed, and Medline using a Boolean “AND”. The search was limited to articles published after December 2012 since this was the end of the period reviewed since the last review paper . The original search was conducted on January 24th, 2019, then repeated at each revision, on March 24th, 2019, October 28th, 2019, and November 12th, 2020, to be thorough. The initial search identified 268 articles. After duplicates across search engines were removed, articles were screened by the primary author based on titles and abstracts. For the screening process, full articles were retrieved and reviewed to confirm relevance and eligibility. The primary author extracted data on intervention type, methods, and outcomes. To be included in this review, the article must have been an RCT that examined a psychotherapeutic intervention for participants who met criteria for T2DM at the time of recruitment and must have changes in HbA1c levels as a health outcome. Only RCT’s were reviewed so as to include only the most scientifically rigorous research on this topic. Studies that used only pharmacological interventions were not included. In addition, interventions that specifically targeted comorbid disorders (e.g., depression in individuals with T2DM) and studies that were not reported in English were also excluded from this review. In the end, 16 articles remained and were reviewed.