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Biomedical subjects

D H Bovbjerg

Publications and source records attributed to D H Bovbjerg.

At least 19 recordsLinked to original sources

Effects of dopamine D2 receptor (DRD2) and transporter (SLC6A3) polymorphisms on smoking cue-induced cigarette craving among African-American smokers.

Cue-induced craving for addictive substances has long been known to contribute to the problem of persistent addiction in humans. Research in animals over the past decade has solidly established the central role of dopamine in cue-induced craving for addictive substances, including nicotine. Analogous studies in humans, however, are lacking, especially among African-American smokers, who have lower quit rates than Caucasian smokers. Based on the animal literature, the study's objective was to test the hypothesis that smokers carrying specific variants in dopamine-related genes previously associated with risk for addictive behaviors would exhibit heightened levels of cigarette craving following laboratory exposure to cues. To this end, cigarette craving was induced in healthy African-American smokers (n=88) through laboratory exposure to smoking cues. Smokers carrying either the DRD2 (D2 dopamine receptor gene) TaqI A1 RFLP or the SLC6A3 (dopamine transporter gene) 9-repeat VNTR polymorphisms had stronger cue-induced cravings than noncarriers (Ps <0.05 and 0.01, respectively). Consistent with the separate biological pathways involved (receptor, transporter), carriers of both polymorphisms had markedly higher craving responses compared to those with neither (P<0.0006), reflecting additive effects. Findings provide support for the role of dopamine in cue-induced craving in humans, and suggest a possible genetic risk factor for persistent smoking behavior in African-American smokers.

Adult↗

Stress-induced cigarette craving: effects of the DRD2 TaqI RFLP and SLC6A3 VNTR polymorphisms.

Animal models have long implicated dopamine in stress-induced craving for a variety of addictive substances. However, translational studies of dopamine, stress and craving in humans are lacking. Based on the animal literature, this study's objective was to test the hypothesis that cigarette smokers carrying specific variants in dopamine-related genes would have heightened levels of cigarette craving following exposure to a laboratory stressor. Cigarette craving induced by controlled exposure to a laboratory stressor was assessed in healthy adult smokers (n=108) recruited by advertisement. Significantly stronger stress-induced cigarette craving was found for individuals carrying either the DRD2 (D2 dopamine receptor gene) A1, or the SLC6A3 (dopamine transporter gene) nine-repeat allelic variants. Stress-induced craving was markedly higher for those carrying both alleles, compared to those with neither, consistent with the separate biological pathways involved (receptor, transporter). Findings provide strong support for the possibility that dopamine involvement in stress-induced craving well established in animal models also applies to humans, and suggest a potential genetic risk factor for persistent smoking behavior.

Adult↗

Stronger endocrine responses after brief psychological stress in women at familial risk of breast cancer.

Recent research has linked exposure to chronic stress to altered acute stress responses and suggests a sensitizing effect of chronic stress leading to a stronger endocrine and cardiovascular response to acute stressors. Substantial evidence indicates that familial breast cancer risk is a chronic life stressor with higher levels of self reported distress. In this study, we investigated whether the endocrine response to a brief psychological stressor was stronger for women at familial risk for breast cancer. Thirty-six women at normal risk of breast cancer (FR- Stress Group) and 17 women at familial risk (FR+ Stress Group) underwent a brief psychological laboratory stress test (speech task and mental arithmetic) over a 15 min period. Thirty women at normal risk not subjected to the stressful task served as controls (FR- Control Group). Plasma epinephrine, norepinephrine and cortisol were measured at baseline, directly after the stress test (15 min) and at 30 min and 45 min post baseline. Heart rate data confirmed the effectiveness of the stress regimen. While there were no significant baseline group differences in the endocrine parameters, the response curves for the familial risk group revealed stronger epinephrine and cortisol reactivity to the stress test, as confirmed by significant group by time interactions. Norepinephrine levels showed a similar pattern, but results did not reach significance. These findings are in line with previous research documenting the facilitating effects of chronic stressors on acute stress response in animals and humans and provide the first evidence in the literature of a heightened endocrine reactivity to acute psychological stress in women at familial risk of breast cancer. The heightened endocrine reactivity to the experimental tasks seen here suggests that these women may experience stronger responses to stressors in their daily lives. According to the recently proposed concept of allostatic load, repeated overly strong stress responses may cumulatively have negative health implications.

Adult↗

Social support, intrusive thoughts, and quality of life in breast cancer survivors.

This study explores the moderating effect of social support on the relationship between cancer-related intrusive thoughts and quality of life. Sixty-four breast cancer survivors completed self-report measures of appraisal social support (the disclosure of thoughts and feelings to significant others), cancer-related intrusive thoughts, and quality of life. Controlling for demographic and treatment variables, the negative impact of cancer-related intrusive thoughts on both physical and mental quality of life measures was moderated by appraisal social support. For women with high levels of appraisal support, cancer-related intrusive thoughts had no significant relationship with quality of life. However, for women with low levels of appraisal support, the relationship between cancer-related intrusive thoughts and quality of life was significant and negative. These results suggest that appraisal social support can mitigate the impact of traumatic life events.

Adult↗

Specific response expectancies predict anticipatory nausea during chemotherapy for breast cancer.

Clinical research has demonstrated that large numbers of chemotherapy patients continue to experience nausea in the clinic prior to infusions. A better understanding of the mechanisms responsible for such anticipatory nausea (AN) is likely to provide critical information for identifying intervention targets. In the present study the authors investigated the contribution of expectancy, history of nausea, and distress to AN in 60 women with Stage I or II breast cancer receiving standard adjuvant chemotherapy. The predictors were each independently associated with AN (p < .05). However, only expectations significantly predicted AN in simultaneous regression analyses. Results suggest that interventions to reduce AN during chemotherapy should target patients' expectations.

Adult↗

How should we measure blood pressure in the doctor's office?

BACKGROUND: Blood pressure is the most ubiquitous diagnostic recording made in the doctor's office, but the measurement is subject to a number of sources of bias, which may lead to over- or underestimation. The current study examined the systematic influence of the way in which the measurements were taken - by the physician, by a nurse, or with the patient sitting alone, using an automated device. SUBJECTS AND METHODS: Blood pressure was measured in 17 essential hypertensive and 10 white-coat hypertensive individuals. On separate clinic visits, measurements were taken by the attending physician, by a nurse and using an automated device (Arteriosonde 1216). RESULTS: A repeated-measures ANOVA revealed that, for systolic pressure, there was a significant effect of measurement modality on blood pressure. Physician systolic pressures were on average approximately 10 mmHg higher than those taken by a nurse, nurse pressures being approximately 7 mmHg higher than those recorded using Arteriosonde. The effect on diastolic pressure was similar but smaller, and no nurse-Arteriosonde difference was observed. CONCLUSIONS: We conclude that the routine clinical assessment of blood pressure would be more representative of daily ambulatory pressure if an automated device, without doctor or nurse present, were used.

Aged↗

Emotional expressivity and intrusive cognitions in women with family histories of breast cancer: application of a cognitive processing model.

OBJECTIVES: Women with family histories of breast cancer exhibit significant distress and intrusive cognitions about cancer. The role of intrusive cognitions in adjustment to chronic stressors is unclear. While they may be a source of distress in themselves, they may also be part of a cognitive processing strategy that aids in the adaptation process, particularly if they are accompanied by more deliberate processing such as emotional expression. Applying cognitive processing models of stress, the present study examined the role of dispositional emotional expressivity in intrusive cognitions about breast cancer and distress in women dealing with the stressful experience of having a family history of breast cancer. Two competing hypotheses were tested: (1) emotional expressivity is associated with reduced intrusive cognitions and thus lower distress; (2) emotional expressivity buffers the relations between intrusive cognitions and distress. DESIGN: Using a cross-sectional design, hypotheses were addressed with multiple regression analyses according to established methods. METHOD: Healthy women (N = 104) who had one or more first-degree relatives with breast cancer were recruited from cancer screening programs. They completed questionnaires regarding family history of cancer, emotional expressivity, distress, and intrusive cognitions. RESULTS: Emotional expressivity was not associated with reduced intrusive cognitions (Hypothesis 1) but moderated the relations between intrusive cognitions and distress (Hypothesis 2). CONCLUSIONS: The data further our understanding of cognitive processing theories of stress and underline the importance of including emotional expression in interventions, helping women to process the stressful experiences associated with having family histories of breast cancer.

Journal Article↗

It won't happen to me: lower perception of heart disease risk among women with family histories of breast cancer.

BACKGROUND: The threat that breast cancer poses to American women, particularly to women with family histories of the disease, has received widespread attention in both medical and popular literatures. While this emphasis may have laudable consequences on breast cancer screening, it may also have a negative consequence, obscuring women's recognition of their risks for other health threats, such as heart disease. This study examined the possibility that women with family histories of breast cancer may be particularly susceptible to overestimating their risks of breast cancer while minimizing their risks of cardiovascular disease. METHODS: Healthy women with (n = 73) and without n = 104) family histories of breast cancer (64% African American, 26% Caucasian, 10% other ethnicities, mean age 41.7 years) were recruited from medical centers in New York City, and completed questionnaires concerning their family histories and perceptions of risk. RESULTS: Consistent with the study hypothesis, women with family histories of breast cancer had significantly higher perceived lifetime risk of breast cancer (P<0.0002) but lower perceived lifetime risk of heart disease (P<0.002) than women without family histories. Additionally, women with family histories of breast cancer had lower perceived colon cancer risk (P<0.02), suggesting that women with family histories of breast cancer may be underestimating their risks for a variety of diseases. CONCLUSION: The emphasis on breast cancer risk, especially for women with family histories of the disease, may need to be balanced by educational efforts concerning women's risk of other diseases, particularly cardiovascular disease.

Adult↗

Looking forward and back: distress among women at familial risk for breast cancer.

Healthy women with family histories of breast cancer in a first-degree relative (FH+) have been reported to exhibit higher levels of breast cancer-related distress than women without family histories of breast cancer (FH-). Recent data suggest that this may be particularly true for women who had a parent die of cancer. In line with theories emphasizing the psychological impacts of past stressors and concerns for the future, the present study examined the hypotheses that past cancer stressors (i.e. maternal breast cancer caregiving and death, "Looking Back") and perceptions of one's own heightened future risk for developing the disease ("Looking Forward") would predict current levels of distress. One hundred forty-eight healthy women (57 FH+, 91 FH-) recruited from large medical centers in the New York City area completed measures of breast cancer-related distress, general psychological distress, and items assessing whether or not they had taken care of their mother with breast cancer or had had their mother die from the disease. Consistent with previous research, results indicated that FH+ women whose mothers had died of breast cancer had significantly higher breast cancer-related distress than either FH+ women whose mothers had not died of breast cancer or FH- women (p < .05). Further analyses revealed that FH+ women who had cared for their mothers with breast cancer had higher cancer-related distress than women who did not (p < .01), and that FH+ women whose experience included both caregiving and the death of their mother from breast cancer had the highest levels of cancer-related distress (p < .01) and depressive symptoms (p < .05). Findings also indicated that FH+ women with heightened perceptions of risk for breast cancer had higher levels of distress, independent of past stressors. These findings suggest that psychosocial interventions for women with family histories of breast cancer might be appropriately focused on these issues.

Adult↗

Psychological distress, health beliefs, and frequency of breast self-examination.

Although monthly breast self-examination (BSE) is recommended for early breast cancer detection, most women do not comply. Few studies have examined the impact of psychological distress on BSE frequency. Recent research suggests that it may be particularly important to examine the role of distress in the recently identified phenomenon of BSE overperformance (> 1/month). One hundred thirty-five healthy women with and without family histories of breast cancer completed sociodemographic, health belief, general and cancer-specific psychological distress, and BSE frequency questionnaires. The central finding of the study was that BSE underperformance and overperformance had two distinct sets of predictors: health beliefs, specifically barriers against BSE and low confidence in BSE performance, were related to BSE underperformance, while higher levels of psychological distress, particularly cancer-specific intrusive thoughts, were related to BSE overperformance. Findings underscore the need to evaluate BSE under- and overperformance separately and to develop problem-specific interventions to increase compliance with monthly BSE.

Adult↗

Intrusive thoughts and psychological distress among breast cancer survivors: global meaning as a possible protective factor.

Previous research has consistently demonstrated a positive association between intrusive thoughts about stressful experiences and psychological distress. The strength of this relation, however, has varied considerably across studies. To examine the possibility that an individual's sense of global meaning (i.e., the existential belief that one's life has purpose and order) may moderate the relation between intrusive thoughts and psychological distress, the authors conducted telephone assessments of 61 women who had survived breast cancer. Results confirmed that the frequency of intrusive thoughts was positively related to psychological distress. Global meaning, moreover, moderated the relation between intrusive thoughts and psychological distress consistent with the authors' hypotheses. Among women with lower global meaning, more frequent intrusive thoughts were associated with higher psychological distress. No association was found between intrusive thoughts and psychological distress among those participants with higher global meaning.

Adult↗

Patients' pretreatment expectations of chemotherapy-related nausea are an independent predictor of anticipatory nausea.

Based on extensive research with animals, classical conditioning theorists have come to regard contingency as the primary factor in the development of conditioned responses. However, recent experimental work with humans has suggested the possibility that participant expectations may also directly contribute to the development of conditioned responses. To date, this phenomenon has not been investigated in clinical settings. Anticipatory nausea (AN) in chemotherapy patients, widely viewed as the best established example of classical conditioning in clinical medicine, provides an opportunity to examine the contributions of patient expectations to the development of a conditioned response outside the laboratory. The present study of 59 breast cancer patients supported the hypothesis that pretreatment patient expectations make a significant (p < .03) contribution to the development of AN after statistically controlling for the strongest conditioning predictor, contingency. These data imply that patient expectations should be considered when evaluating conditioned responses to aversive medical treatments.

Adult↗

Predictors of intrusive thoughts and avoidance in women with family histories of breast cancer.

Having a family history of cancer is an important predictor of lifetime cancer risk. Individuals with family histories of cancer have been reported to experience symptoms of general distress and to have frequent intrusive thoughts and avoidance regarding cancer. To date, little is known about predictors of such distress. A relation between perception of cancer risk and distress has been suggested, but the possibility that prior cancer-related events may contribute to distress in these women has received little attention. The major aim of the study was to examine the contribution of the past experience of the death of a parent from cancer to distress in women at familiar risk for breast cancer. Women with family histories of breast cancer (Risk Group, N = 46) were assessed on the day of their yearly mammography screening and four to eight weeks after normal result notification in order to confirm the generalizability of their distress. Their levels of intrusive thoughts, avoidance, and perceived lifetime risk for breast cancer were significantly higher than those of women with no family histories of cancer who were not undergoing mammography (Comparison Group, N = 43), and this was true on both assessment days. Among the women in the Risk Group, those whose parent(s) had died of cancer had the highest levels of intrusive thoughts, avoidance, and perceived risk. Results suggested that perceived risk mediated the effect of this event on intrusive thoughts and avoidance regarding breast cancer. The findings are discussed in terms of theories of cognitive responses to traumatic and stressful life events. Implications for future research and interventions are discussed.

Adult↗

The development of anticipatory nausea in patients receiving adjuvant chemotherapy for breast cancer.

Previous research on anticipatory nausea in cancer patients has focused on its occurrence in the clinic before chemotherapy infusions. The present study is the first, to our knowledge, to examine the development of anticipatory nausea across eight chemotherapy infusions for three time periods (night before, morning of, and immediately prior to each infusion). Based on classical conditioning experiments conducted with animal subjects, we hypothesized that the severity of anticipatory nausea would increase as the time for scheduled infusions approached. Eighty-two women diagnosed with Stage I or II breast cancer were assessed for the intensity of anticipatory nausea at three time periods prior to eight scheduled infusions of outpatient adjuvant chemotherapy. Analyses indicated a significant interaction between number of infusions experienced and temporal proximity to the infusion, supporting the hypothesis. Changes in the severity of anticipatory nausea across infusions were consistent with conditioned learning predictions. These results contribute to a growing recognition of the importance of conditioning principles for understanding side effects of chemotherapy for cancer and may have implications for the management of side effects secondary to a variety of pharmacotherapies in clinical practice.

Antineoplastic Combined Chemotherapy Protocols↗

Imagery in human classical conditioning.

Many clinical strategies use patients' imagery to explore and treat phobic and posttrauma reactions, however little attention has been paid to the underlying assumption that imagery of relevant stimuli may help maintain conditioned behavior. In this article, the authors examine the premise that mental images can potentiate and substitute for physical stimuli in human classical conditioning. The authors review empirical evidence to detail the role of images of conditioned stimuli (CS) and unconditioned stimuli (US) during pre-exposure to stimuli, the actual pairing of the CS and US, and extinction when the CS is presented alone. The evidence suggests that mental imagery can facilitate or diminish the outcome of classical conditioning in humans and, more tentatively, that mental images can substitute for actual US and CS in autonomic conditioning. They argue that researchers should explore the role of mental imagery in conditioning through the use of advances in the measurement of imagery. Finally, they analyze anxiety and trauma reactions as examples of how applied areas can be used to explore and benefit from developments in this area.

Animals↗

Classically conditioned changes in plasma cortisol levels induced by dexamethasone in healthy men.

Animal research has indicated that the activity of the hypothalamic-pituitary-adrenal axis can be influenced by classical (Pavlovian) conditioning procedures. To test the hypothesis that alterations in plasma cortisol levels can be conditioned in humans, the present study used a prospective, randomized, double-blind, placebo-controlled design in which a distinctively flavored beverage was paired with p.o. administration of dexamethasone. Twenty-five healthy men were randomly assigned to one of two groups. During the conditioning phase of the study, subjects in the experimental group received three conditioning trials (pairings of a distinctively flavored beverage with a capsule containing 5 mg dexamethasone) separated by 1 wk recovery periods. Subjects in the control group were treated identically, except that the capsule contained a placebo. During the test phase, all subjects underwent a test day (reexposure to the distinctively flavored beverage before receiving a placebo capsule) and a comparison day (no exposure to the beverage or the capsule). Plasma cortisol was assessed repetitively before and after administration of the beverage and capsule, as were possible confounding factors, including: behavioral variables, psychological distress, aversive reactions to the beverage, and expectations of treatment. After reexposure to the beverage and administration of a placebo capsule (conditioned stimuli), the experimental group had significantly higher levels of plasma cortisol than the control group, after controlling for variability in baseline levels of cortisol (F(5,60)=3.09; P=0.015) that could not be explained by differences in other study variables. No differences in cortisol levels were found on the comparison day. These results support the study hypothesis that changes in plasma cortisol levels can be classically conditioned in humans by pairing a distinctive beverage with p.o. administration of dexamethasone.

Adult↗

Conditioned reactions to cancer chemotherapy: percent reinforcement predicts anticipatory nausea.

Current theorizing on classical conditioning has emphasized the role of contingent relations between the conditioned and unconditioned stimuli in the development of conditioned responses. The present study is the first to examine the relevance of this concept to our understanding of the phenomenon of anticipatory nausea in cancer chemotherapy patients. Anticipatory nausea in patients receiving emetogenic chemotherapy has been cited as an example of the importance of classical conditioning in clinical medicine. Outpatient chemotherapy can be viewed as a series of conditioning trials in which the previously neutral stimuli of the clinic (conditioned stimuli) are associated with chemotherapy infusions and postinfusion nausea. Reexposure to these clinic stimuli alone is sufficient to elicit nausea (conditioned response) in some patients prior to subsequent infusions. In the present study we examined whether differences among patients in percent reinforcement (the percentage of infusions followed by nausea) would predict anticipatory nausea, which was assessed at the sixth infusion. Results were consistent with the hypothesis. Percent reinforcement was positively correlated with the incidence of anticipatory nausea. Comparison of patients with and without anticipatory nausea (t-test and hierarchical logistic regression analysis) confirmed that percent reinforcement was a significant predictor of anticipatory nausea, independent of other factors previously reported to be involved.

Adult↗