Personality and Dispositional Factors in Relation to Chronic Disease Management and Adherence to Treatment
KeywordsPersonality Trait Medication Adherence Personality Disorder Dispositional Optimism Dispositional Factor
Big Five; Carcinoma; Excess adiposity; FFM; Hyperglycemia; Hypoglycemia; Insulin resistance; Joint stiffness or inflammation; Lifestyle disorder; Malignant tumor or growth; Medical condition; Metabolic disease; Neuroticism; Optimism; Overweight; Respiratory disease; Treatment adherence or compliance; Type A personality; Type B personality; Type D personality
Adherence Versus Compliance
Adherence and compliance are often used synonymously, but really have slightly different meanings. Compliance is defined as conforming to a physician’s advice and recommendations, whereas adherence is about following a physician’s advice and recommendations after a physician and patient have come to an agreement about the treatment plan (Ganiyu et al. 2013). Good adherence often refers to taking medication as prescribed, but it can also reflect following a physician’s advice about quitting smoking, exercising daily, and/or eating a healthy diet.
This model consists of five personality domains that range from low to high levels and include agreeableness, conscientiousness, extraversion, neuroticism, and openness to experience. Agreeableness indicates how altruistic, trusting, and cooperative one is in general. Conscientiousness is linked to the amount of social norms adherence and self-control that individual possesses. Extraversion defines how social and socially assertive an individual is, while neuroticism describes a person’s level of emotional stability. Finally, openness to experience is described on the basis of one’s level of curiosity and interest in the opinions of others (Jokela et al. 2013).
This personality characteristic allows individuals to have a positive attitude about future events. Individuals with high levels of dispositional optimism are much more likely to make healthy lifestyle choices (Kreis et al. 2015; Kwissa-Gajewska et al. 2014).
Interpersonal Dependency and Detachment
People with high levels of dependence on their physician are described as being interpersonally dependent, whereas those who are disconnected from their physician would be labeled as detached (Porcerelli et al. 2015).
Type B Personality
Individuals with a type A personality are highly competitive, aggressive, always in a rush, impatient, and hostile. Individuals with type B personality are described as the opposite of type B, which means they exhibit low levels of competitiveness, aggressiveness, rushed behavior, impatience, and, finally, hostility (Hagihara et al. 1997).
Type D Personality
Individuals with this personality trait have high levels of negative emotions and social inhibition. This is a difficult personality characteristic to have since these individuals struggle with a great deal of negative affectivity, but feel uncomfortable expressing how they feel due to concerns about how they will be evaluated by others (Li et al. 2016; Nefs et al. 2015).
The leading causes of death for adults in the USA are chronic diseases, such as cancer and type 2 diabetes (Centers for Disease Control and Prevention; CDC 2016). These diseases not only have an estimated medical cost of billions per year but also have an incalculable personal impact on the millions of individuals who suffer from them (CDC 2016). Most health-care expenditures are due to individuals suffering from one or more of these “lifestyle disorders” (CDC 2016). These conditions are so named because many of the factors involved in their development, progression, and/or management are health behaviors that are modifiable and, therefore, preventable or treatable. Key lifestyle behaviors include medication or inhaler use, symptom monitoring, diet, physical activity, smoking, and sleep (CDC 2016). The corresponding treatments for such lifestyle diseases are also multifaceted and long term (i.e., a single pill typically does not suffice and treatments may be lifelong). Consequently, disease management and treatment adherence have become a major focus of research and clinical efforts. As might be expected, personality and other dispositional factors have been implicated in these disorders and their management. Thus, the goal of this entry is to present the most recent data (published from 2011–2016) on personality/dispositional factors among persons with these costly medical disorders as well as the impact of these factors on disease management and treatment adherence.
This entry is limited to the following chronic diseases among adults: arthritis, asthma, cancer, types 1 and 2 diabetes, and obesity. The selection rationale is that these diseases confer a high burden of self-management, disability, and cost and have been less represented in previous work. Notably, cardiovascular disease is not included given its already substantial literature, despite the fact that it is the leading cause of death in the USA. Each section below begins with a working definition of the disease, provides brief prevalence rates and standard treatments, and then summarizes the recent research of personality/dispositional factors as they relate to each disease. Disease categories are presented alphabetically.
Arthritis encompasses over 100 rheumatic diseases and conditions related to joint problems, with one in every six adults presenting with some form of an arthritic condition (http://www.cdc.gov/arthritis/). Consequently, arthritis is reported as the number one cause of disability in the USA. Rheumatoid and osteoarthritis are the most common forms of arthritis. Depending on the diagnosis and/or the severity of the arthritic condition, patients can be successfully treated with pain and anti-inflammatory medications, antirheumatic medication, biologic medications, self-management education, physical activity, and/or weight loss (http://www.cdc.gov/arthritis/).
Much of the research pertaining to arthritis investigates the impact of optimism and neuroticism on individuals’ perception of their pain levels. The majority of participants in these studies are female (Benka et al. 2014; Bucourt et al. in press; Kwissa-Gajewska et al. 2014), which is likely due to the fact that arthritis is more common among women compared to men. As a result of the debilitating nature of arthritis, neuroticism is an underlying personality trait that negatively influences adherence to treatment protocols (Benka et al. 2014; Bucourt et al. in press; Hyphantis et al. 2013). Patients with a neurotic personality tend to catastrophize more about pain than their optimistic counterparts. This catastrophic thinking leads to increased attention on the pain resulting in increased pain levels, decreases in activity, and poorer adherence to treatment. Optimism is also a dispositional factor that is a common focus of research. Arthritic patients with a high level of dispositional optimism tend to report not only lower levels of pain and less pain catastrophizing but also better adherence to exercise treatment and less use of pain medication (Goodin et al. 2013; Kreis et al. 2015; Kwissa-Gajewska et al. 2014).
The current research on arthritis and personality is limited and needs to be expanded to a more heterogeneous population (i.e., males and non-European countries) and other personality traits. In addition to examining additional personality factors (e.g., five-factor model or personality disorders), mechanistic studies would also enhance the literature. For example, examining whether the pain-optimism relationship is a function of the placebo effect or some underlying physiological phenomenon could guide treatment targets. Another untapped area of research would be to examine if tailoring treatment protocols based on the patient’s personality would improve pain management and adherence for patients with arthritis.
Asthma is a chronic lung condition in which airways become constricted and inflamed leading to wheezing, coughing, and shortness of breath. Sixteen percent of the US population is currently diagnosed with asthma (http://www.cdc.gov/asthma/asthmadata.htm). Asthma symptoms are successfully controlled via inhaled medications, which include corticosteroids that are taken on regular basis and short-acting beta2-agonists (e.g., albuterol) which are taken as needed (http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/). Individuals choosing not to follow their physician’s advice regarding medication are at risk of having uncontrolled asthma which is linked to lower quality of life, more lost work or school days, more health-care costs, and, ironically, more physician visits compared to those with controlled asthma (Braido 2013). In addition to perceptions about the disease, rapport issues with providers, inhaled medication techniques, and medication side effects, personality traits have been related to poorer medication adherence among persons with asthma (Axelsson and Lötvall 2012).
In the realm of personality traits, the most recent research has focused on relationships between the five-factor model and medication adherence among men and women. Low conscientiousness has been the personality domain most often associated with poor medication adherence. Axelsson and various colleagues are credited with publishing the majority of the current studies on five-factor model and medication adherence. Their largest sample had over 500 persons with asthma, and the findings indicated that low medication adherence was significantly related to low conscientiousness in addition to high neuroticism and low agreeableness (Axelsson et al. 2013). However, all of these relationships have not been found in every study, particularly among women.
The literature regarding personality traits and medication adherence in individuals with asthma is an emerging area and could benefit from objective measures of adherence and recruiting larger samples. Additionally, the relationship between medication adherence and other personality factors (e.g., type D personality, personality disorders) needs to be considered. Research has also yet to explore the value of assessing personality in order to select the best approach for encouraging medication adherence among adults with asthma (Axelsson and Lötvall 2012).
Cancer is the second leading cause of death behind heart disease with an estimated 1.7 million cases that will be diagnosed in 2016 (CDC 2016). An estimated 600,000 patients will die from the disease in the USA alone. Cancer treatments vary depending on the cancer diagnosis and severity and may include chemotherapy, radiation, surgery, immunotherapy, targeted therapy, hormone therapy, stem cell therapy, precision medicine, and palliative care. Palliative care is intended to treat or prevent the physical, psychological, or social consequences of the cancer or its treatment, with the primary goal to improve quality of life (http://cancer.org/about-cancer/understanding/statistics). The more extensive treatment protocols (chemotherapy and radiation) can suppress the immune system, creating an opportunity for other diseases to negatively impact the patient’s health and possibly lead to premature death. Another result of the treatment may be ongoing fatigue and pain. Cancer-related variables (types of treatment and severity of disease) can negatively impact clinical outcomes. In addition, other factors can influence clinical outcomes such as age, social support, the physician-patient relationship, coping strategies, and personality traits. Poor or nonadherence to treatment protocols can result in death.
Factors that could potentially moderate adherence are patient anxiety levels, dependence on the physician, and neurotic personality. Depression and high levels of anxiety are more common in cancer patients versus normal healthy individuals (Shimizu et al. 2015). Patients with a variety of cancer diagnoses who scored high on a scale measuring interpersonal dependency had more negative outcomes, such as poor adherence to treatment, compared to patients who reported being detached from their physician (Porcerelli et al. 2015). These traits, interpersonal dependency, and detachment seemed to moderate the adjustment to treatment. This resulted in a lack of adherence to the treatment program. In another study with prostate cancer patients, it was reported that personality traits, such as neuroticism or agreeableness, were associated with specific health-care preferences for treatment (Lattie et al. 2016). Patients who were service reluctant presented with higher levels of neuroticism (emotional instability and negativity) and poor adherence to prescribed treatment. This type of patient preferred minimal engagement with the health-care system. In contrast, comfort-oriented patients were more likely to present with more agreeableness and adherence to treatment protocols. Regarding personality traits in lung cancer patients, those with neurotic tendencies endorsed higher anxiety, which resulted in lack of adherence, less-effective patient decision-making, and disruption in cancer care (Shimizu et al. 2015). In a study of nonmetastatic breast cancer patients, lower quality of life scores were more strongly related to premorbid trait anxiety and neuroticism than to the cancer-related variables (Brunault et al. 2015). Neuroticism seems to be the common trait in predicting a patient’s adherence to medical treatments for cancer. Brunault et al. (2015) suggest that administering a personality profile may be a prudent addition to any treatment protocol and enhance the health-care professional’s understanding of the patient, resulting in the potential for improved treatment adherence.
The research on personality and treatment adherence among cancer patients lacks depth but is an emerging field of inquiry. Thus far, studies have not concentrated on one type of cancer, and the demographic characteristics of participants have varied, making it difficult to compare study findings. The current research has focused on one particular personality trait which is neuroticism due to its association with anxiety, which is evident in most cancer patients (Brunault et al. 2015; Porcerelli et al. 2015; Shimizu et al. 2015). The notion of interpersonal dependency (Porcerelli et al. 2015) is relatively new and may shed some light on future treatment programs and research to improve treatment adherence and clinical outcomes.
Diabetes: Types 1 and 2
Over 29 million people in the USA have been diagnosed with diabetes, and another 8.1 million are not yet aware that they have the disease (CDC 2014). Diabetes occurs when glucose levels are abnormally high due to a problem with insulin levels. In type 1, an individual’s pancreas cells which are responsible for producing insulin are destroyed via an autoimmune process, resulting in the patient having little to no insulin available. Type 2 is associated with a resistance to insulin’s effects and typically develops later in life than type 1. Management of diabetes is complex, often requiring medication as well as behavioral changes. For example, injectable insulin is required for individuals with type 1 diabetes, and this treatment requires individuals to monitor their blood sugar along with physical activity and foods eaten. Once someone is diagnosed with type 1 diabetes, they will need to severely limit or avoid particular foods, such as simple carbohydrates. Individuals with type 2 diabetes may or may not need to take injectable insulin, but they will likely be prescribed an oral hypoglycemic drug and possibly other drugs (e.g., blood pressure medication), since diabetes is often comorbid with other diseases (García-Pérez et al. 2013). Individuals with type 2 will be required to shift to a diet appropriate for a diabetes diagnosis and increase their activities. Poor management of diabetes places an individual at a higher risk of diabetes-related complications such as kidney disease, heart disease, stroke, blindness, amputations, and premature mortality.
It is not surprising that nonadherence is high among individuals with type 2 diabetes given that self-management of this disease is challenging. There has been an interest in examining whether personality factors are linked to nonadherence. Although researchers have investigated the relationship between personality traits and treatment adherence in both type 1 and type 2 diabetes, the literature published in the last 5 years has focused primarily on adherence and type B personality, type D personality, and big five personality traits among individuals diagnosed with type 2 diabetes.
Individuals categorized as type D personality have exhibited lower medication adherence 6 months later compared to those not labeled as type D (Li et al. 2016). Also, patients with type 2 diabetes have been significantly more likely to have type D or B personalities compared to healthy individuals. Further, in comparison to non-type D patients, those with type D have been more adherent regarding monitoring their blood glucose but less likely to attend primary care physician appointments (Milicevic et al. 2015). One possible explanation for the latter finding about appointments could be due to having a high level of negative affectivity. For example, individuals with type 1 or type 2 diabetes and who also had a type D personality were significantly more likely to cancel a medical appointment compared to individuals who did not have a type D personality or only had the high social inhibition component of the type D. However, although there were no differences among the groups regarding medication adherence, the combination of high negative affectivity and high social inhibition (type D personality) was associated with the greatest number of barriers to taking medication and the most unhealthy eating compared to all other groups (Nefs et al. 2015). These studies suggest that type D personality in those with diabetes is related to attending fewer medical appointments and might be associated with lower medication adherence but better blood glucose monitoring than individuals with diabetes who do not have a type D personality. More research is needed to replicate these findings and clarify the mixed results regarding medication adherence.
Recent studies have also focused on investigating whether the five-factor model is linked to a variety of adherence-related outcomes among individuals with diabetes. For example, high conscientiousness has been associated with a lower BMI, no smoking, and higher medication adherence after adjusting for age and sex from the longitudinal Fremantle Diabetes Study Phase II of over 1700 type 1 and 2 diabetic patients (Skinner et al. 2014). High conscientiousness and high agreeableness were also each associated with monitoring blood glucose levels after adjusting for age and sex.
Louch and colleagues (2013) conducted a small trial in which 19 participants (8 male, 11 female) diagnosed with type 1 diabetes were randomized to an intervention or control group. The intervention group received a daily text message about correctly administering insulin, and the control group was provided with a text message once a week about general health. All participants completed a baseline assessment which included the NEO Personality Inventory Domain scale to assess conscientiousness, a scale to measure consideration of future consequences, and a self-report of morning, afternoon, and evening insulin injections. The intervention resulted in more frequent evening injections for individuals low in conscientiousness and low in consideration of future consequences compared to participants in the control group. Although this is a small study in need of replication, a longer follow-up, and an objective measure of medication adherence, the findings suggest that text messaging is a feasible approach to target individuals with diabetes who struggle with a five-factor model personality issue.
Finally, other studies have examined the important question of whether the five-factor model was associated with the risk of developing type 2 diabetes. Neuroticism was significantly associated with a lower risk of diabetes in a sample of over 6700 participants enrolled in the Epidemiological Follow-up Cohort of the National Health and Nutrition Examination Survey (Čukić and Weiss 2014). On the other hand, after adjusting for physical activity levels, smoking, body mass index, and high blood pressure, lower conscientiousness was linked to a higher risk of diabetes on the basis of five longitudinal studies of over 34,000 individuals (Jokela et al. 2013). It remains to be seen if and how personality might be related to adherence to advice from physicians regarding health behaviors and the subsequent risk for type 2 diabetes.
Obesity is a medical condition characterized by having excess adipose or fat tissue relative to a person’s height. The standard definition is a body mass index (BMI) of 30 kg/m2 (http://www.cdc.gov/obesity/). Currently, one of every three adults in the USA is estimated to be obese (http://stateofobesity.org/). Obesity is linked to higher risk of developing comorbid medical disease, including those mentioned in this entry: arthritis, cancer, cardiovascular disease, and type 2 diabetes, as well as higher mortality rates. Gold standard treatments for obesity are predominantly cognitive-behavioral (e.g., stimulus control, self-monitoring) with the goal of reduced calorie intake and increased energy expenditure whereas severe obesity is now routinely treated with surgical interventions (e.g., sleeve gastrectomy and Roux-en-Y gastric bypass). Unfortunately, lasting weight loss is rare with the majority of persons regaining their weight within 5 years. Personality factors have been implicated in both obesity development and treatment.
Of the FFM personality traits, conscientiousness has been most consistently and robustly linked to obesity and related adherence behaviors (e.g., physical activity). The largest recent study examined data from nearly 80,000 adults in the USA, United Kingdom, Germany, and Australia. Meta-analytic evidence from this report suggests that that high conscientiousness predicts reduced risk of developing obesity among initially nonobese persons over an average follow-up of 5 years (Jokela et al. 2013). In this study, conscientiousness was also linked to successful weight loss among obese persons. None of the other five-factor model traits were related to obesity outcomes. Relatedly, conscientiousness – along with openness – has also been linked to increases in physical activity (Allen et al. 2016) and with healthy eating (Lunn et al. 2014); both behaviors have been identified as contributors to losing weight and maintaining weight loss. Low conscientiousness has even been linked to higher circulating levels of leptin and possible leptin resistance, which may impact a person’s appetite and satiety signals (Sutin et al. 2013). This study of over 5000 adults failed to find any association between leptin and any other five-factor model trait. Personality factors such as impulsivity and poor organization have also been linked to higher attrition from obesity treatments (Moroshko et al. 2011) and to suboptimal weight loss and poorer adherence following bariatric surgery (Marek et al. 2015). Indeed, the presence of personality pathology before bariatric surgery has been one of the only psychosocial factors clearly and consistently linked with poorer weight loss outcomes (Livhits et al. 2012).
Together, the evidence suggests that the key features of high conscientiousness (i.e., self-discipline, task orientation, organization, and planning) may be helpful for avoiding obesity or treating it. Similarly, aspects of low conscientiousness (e.g., poor self-control/inhibition, impulsivity, and poor planning) are likely detrimental to keeping or achieving a healthy weight. These findings have implications for screening and treatment as obese persons who are low in conscientiousness may benefit from early or added intervention to ensure their adherence and success in weight loss treatment efforts.
Experiencing and managing the aforementioned disorders is challenging. Medication and monitoring regimens are typically complex and/or require daily action and doses at multiple time points (e.g., glucose monitoring, calorie tracking). A multitude of non-personality factors have already been identified that prohibit adherence to medication, diet, or exercise, all components related to improving outcomes in the aforementioned diseases. Using diabetes as a prototype, nonadherence in regards to medication is related to multiple prescribed medications, incorrect beliefs about medication, side effects or adverse events, and, for some, medication costs (Garcia-Perez et al. 2013). Nonadherence to diet recommendations is associated with an older age, female gender, poor knowledge about disease, eating meals out, self-reported poor discipline, and limited economic resources (Ganiyu et al. 2013; Parajuli et al. 2014). Poor adherence to physical activity recommendations is also associated with limited economic resources, in addition to being divorced, having a lack of a family history of diabetes, possessing the inaccurate viewpoint that exercise exacerbates symptoms of diabetes, and other factors often cited by individuals without diabetes (e.g., poor weather, no one to exercise with currently; Ganiyu et al. 2013; Parajuli et al. 2014).
Replication of smaller studies
Expansion to more diverse populations
Greater use of longitudinal designs
Determination of whether screening for personality/dispositional factors is useful for identifying at-risk groups
Investigating whether personality disorder diagnoses impact adherence among patients with diseases besides obesity
Examination of tailoring intervention by personality/disposition to improve disease outcomes
Exploring these lines of inquiry could yield results that would allow us to improve the prognosis of individuals suffering from chronic diseases.
- Allen, M. S., Magee, C. A., Vella, S. A., & Laborde, S. (2016). Bidirectional associations between personality and physical activity in adulthood. Health Psychology.Google Scholar
- Benka, J., Nagyova, I., Rosenberger, J., Macejova, Z., Lazurova, I., Van der Klink, J., …, Van Dijk, J. (2014). Is coping self-efficacy related to psychological distress in early and established rheumatoid arthritis patients? Journal of Developmental and Physical Disabilities, 26(3), 285–297.Google Scholar
- Braido, F. (2013). Failure in asthma control: Reasons and consequences. Scientifica, 2013(Article ID 549252), 15.Google Scholar
- Brunault, P., Champagne, A. L., Huguet, G., Suzanne, I., Senon, J. L., Body, G., …, Réveillère, C. (2015). Major depressive disorder, personality disorders, and coping strategies are independent risk factors for lower quality of life in non-metastatic breast cancer patients. Psycho-Oncology, 25, 513–520.Google Scholar
- Bucourt, E., Martaillé, V., Mulleman, D., Goupille, P., Joncker-Vannier, I., Huttenberger, B., …, Courtois, R. (in press). Comparison of the big five personality traits in fibromyalgia and other rheumatic diseases. Joint Bone Spine.Google Scholar
- Centers for Disease Control and Prevention. (2014). National diabetes statistics report: Estimates of diabetes and its burden in the United States, 2014. Atlanta: Department of Health and Human Services.Google Scholar
- Centers for Disease Control and Prevention; CDC. (2016). Chronic diseases: The leading causes of death and disability in the United States. Chronic Diseases and Health Promotion. Retrieved 4 July 2016, from http://www.cdc.gov/chronicdisease/overview/.
- Ganiyu, A. B., Mabuza, L. H., Malete, N. H., Govender, I., & Ogunbanjo, G. A. (2013). Non-adherence to diet and exercise recommendations amongst patients with type 2 diabetes mellitus attending extension ii clinic in botswana. African Journal of Primary Health Care & Family Medicine, 5(1), 457.CrossRefGoogle Scholar
- Goodin, B. R., Glover, T. L., Sotolongo, A., King, C. D., Sibille, K. T., Herbert, M. S., …, Redden, D. T. (2013). The association of greater dispositional optimism with less endogenous pain facilitation is indirectly transmitted through lower levels of pain catastrophizing. The Journal of Pain, 14(2), 126–135.Google Scholar
- Kreis, S., Molto, A., Bailly, F., Dadoun, S., Fabre, S., Rein, C., …, Pertuiset, E. (2015). Relationship between optimism and quality of life in patients with two chronic rheumatic diseases: Axial spondyloarthritis and chronic low back pain: A cross sectional study of 288 patients. Health and Quality of Life Outcomes, 13(1), 1.Google Scholar
- Lattie, E. G., Asvat, Y., Shivpuri, S., Gerhart, J., O'Mahony, S., Duberstein, P., & Hoerger, M. (2016). Associations between personality and end-of-life care preferences among men with prostate cancer: A clustering approach. Journal of Pain and Symptom Management, 51(1), 52–59.CrossRefPubMedGoogle Scholar
- Li, X., Zhang, S., Xu, H., Tang, X., Zhou, H., Yuan, J., …, Zhu, H. (2016). Type D personality predicts poor medication adherence in chinese patients with type 2 diabetes mellitus: A six-month follow-up study. PLoS One, 11(2), e0146892.Google Scholar
- Livhits, M., Mercado, C., Yermilov, I., Parikh, J. A., Dutson, E., Mehran, A., …, Gibbons, M. M. (2012). Preoperative predictors of weight loss following bariatric surgery: Systematic review. Obesity Surgery, 22(1), 70–89.Google Scholar
- Marek, R. J., Tarescavage, A. M., Ben-Porath, Y. S., Ashton, K., Rish, J. M., & Heinberg, L. J. (2015). Using presurgical psychological testing to predict 1-year appointment adherence and weight loss in bariatric surgery patients: Predictive validity and methodological considerations. Surgery for Obesity and Related Diseases, 11(5), 1171–1181.CrossRefPubMedGoogle Scholar
- Nefs, G., Speight, J., Pouwer, F., Pop, V., Bot, M., & Denollet, J. (2015). Type D personality, suboptimal health behaviors and emotional distress in adults with diabetes: Results from diabetes miles–the Netherlands. Diabetes Research and Clinical Practice, 108(1), 94–105.CrossRefPubMedGoogle Scholar
- Porcerelli, J. H., Bornstein, R. F., Porcerelli, D., & Arterbery, V. E. (2015). The complex role of personality in cancer treatment: Impact of dependency-detachment on health status, distress, and physician-patient relationship. The Journal of Nervous and Mental Disease, 203(4), 264.CrossRefPubMedPubMedCentralGoogle Scholar
- Shimizu, K., Nakaya, N., Saito-Nakaya, K., Akechi, T., Ogawa, A., Fujisawa, D., …, Iwasaki, M. (2015). Personality traits and coping styles explain anxiety in lung cancer patients to a greater extent than other factors. Japanese Journal of Clinical Oncology, 45(5), 456–463.Google Scholar
- Sutin, A. R., Zonderman, A. B., Uda, M., Deiana, B., Taub, D. D., Longo, D. L., …, Terracciano, A. (2013). Personality traits and leptin. Psychosomatic Medicine, 75(5), 505.Google Scholar