Sex moderates the effects of positive and negative affect on clinical pain in patients with knee osteoarthritis.

BACKGROUND AND AIMS: Sex differences in clinical pain severity and response to experimental pain are commonly reported, with women generally showing greater vulnerability. Affect, including state (a single rating) and stable (average daily ratings over two weeks) positive affect and negative affect has also been found to impact pain sensitivity and severity, and research suggests that affect may modulate pain differentially as a function of sex. The current study aimed to examine sex as a moderator of the relationships between affect and pain-related outcomes among participants with knee osteoarthritis (KOA). METHODS: One hundred and seventy-nine participants (59 men) with KOA completed electronic diaries assessing clinical pain, positive affect, and negative affect. A subset of participants (n=120) underwent quantitative sensory testing, from which a single index of central sensitization to pain was derived. We used multiple regression models to test for the interactive effects of sex and affect (positive versus negative and stable versus state) on pain-related outcomes. We used mixed effects models to test for the moderating effects of sex on the relationships between state affect and pain over time. RESULTS: Sex differences in affect and pain were identified, with men reporting significantly higher stable positive affect and lower central sensitization to pain indexed by quantitative sensory testing, as well as marginally lower KOA-specific clinical pain compared to women. Moreover, there was an interaction between stable positive affect and sex on KOA-specific clinical pain and average daily non-specific pain ratings. Post hoc analyses revealed that men showed trends towards an inverse relationship between stable positive affect and pain outcomes, while women showed no relationship between positive affect and pain. There was also a significant interaction between sex and stable negative affect and sex on KOA-specific pain such that men showed a significantly stronger positive relationship between stable negative affect and KOA-specific pain than women. Sex did not interact with state affect on pain outcomes. CONCLUSIONS: Findings suggest that men may be particularly sensitive to the effects of stable positive affect and negative affect on clinical pain. Future work with larger samples is needed in order to identify potential mechanisms driving the sex-specific effects of affect on pain. IMPLICATIONS: The current study provides novel data that suggesting that the association of positive affect, negative affect, and pain are different in men versus women with KOA. Further understanding of the difference in affective expression between men and women may lead to the development of novel therapeutic interventions and help to identify additional modifiable factors in the prevention and management of pain.

Validation of a Wireless, Self-Application, Ambulatory Electroencephalographic Sleep Monitoring Device in Healthy Volunteers.

STUDY OBJECTIVES: To evaluate the validity of an ambulatory electroencephalographic (EEG) monitor for the estimation of sleep continuity and architecture in healthy adults. METHODS: Healthy, good sleeping participants (n = 14) were fit with both an ambulatory EEG monitor (Sleep Profiler) and a full polysomnography (PSG) montage. EEG recordings were gathered from both devices on the same night, during which sleep was permitted uninterrupted for eight hours. The study was set in an inpatient clinical research suite. PSG and Sleep Profiler records were scored by a neurologist board certified in sleep medicine, blinded to record identification. Agreement between the scored PSG record, the physician-scored Sleep Profiler record, and the Sleep Profiler record scored by an automatic algorithm was evaluated for each sleep stage, with the PSG record serving as the reference. RESULTS: Results indicated strong percent agreement across stages. Kappa was strongest for Stage N3 and REM. Specificity was high for all stages; sensitivity was low for Wake and Stage N1, and high for Stage N2, Stage N3, and REM. Agreement indices improved for the manually scored Sleep Profiler record relative to the autoscore record. CONCLUSIONS: Overall, the Sleep Profiler yields an EEG record with comparable sleep architecture estimates to PSG. Future studies should evaluate agreement between devices with a clinical sample that has greater periods of wake in order to better understand utility of this device for estimating sleep continuity indices, such as sleep onset latency and wake after sleep onset.

When Parents and Adolescents Disagree About Disagreeing: Observed Parent-Adolescent Communication Predicts Informant Discrepancies About Conflict.

Adolescence is accompanied by increased stress in the parent-adolescent relationship, which frequently results in conflict. Researchers often rely on self-reports to measure conflict, but these reports are frequently discrepant from one another. In two studies, we examined the extent to which communication observed during parent-adolescent discussions of conflict were associated with discrepancies in reports about conflict. We also examined links between informant depressive symptoms and discrepancies. Across studies, observed parent-adolescent conflict behaviors consistently predicted absolute discrepancies in reports of conflict. Informant depressive symptoms sometimes predicted directional discrepancies in reports. Results suggest that informant discrepancies about conflict may stem, in part, from a lack of open communication in the relationship.

One-Year Test-Retest Reliability of the Maryland Resource for the Behavioral Utilization of the Reinforcement of Negative Stimuli (MRBURNS).

The Maryland Resource for the Behavioral Utilization of the Reinforcement of Negative Stimuli (MRBURNS) is a novel behavioral task designed to measure individual differences in negative reinforcement-based risk taking propensity. Performance on the MRBURNS has been linked with alcohol-related problems and negative reinforcement-based drinking motives, as well as symptoms of anxiety and depression; however, it is unclear if performance on the task represents a stable measure of negative reinforcement-based risk taking over time. As such, the current study aimed to examine the test-retest reliability of the MRBURNS over a period of one year. Results indicate that the correlation between year 1 and year 2 risk behavior (average number of pumps) on the MRBURNS was .43 across all trials. With the one year test-retest reliability of the MRBURNS established, the MRBURNS may be a useful approach to measuring the relative contribution of negative reinforcement-based risk taking in the development of risky behaviors over time, and may be used to monitor the effects of novel interventions that aim to reduce negative reinforcement based risk taking in the real world.

Social anxiety, acute social stress, and reward parameters interact to predict risky decision-making among adolescents.

Risk-taking behavior increases during adolescence, leading to potentially disastrous consequences. Social anxiety emerges in adolescence and may compound risk-taking propensity, particularly during stress and when reward potential is high. However, the manner in which social anxiety, stress, and reward parameters interact to impact adolescent risk-taking is unclear. To clarify this question, a community sample of 35 adolescents (15-18yo), characterized as having high or low social anxiety, participated in a study over two separate days, during each of which they were exposed to either a social stress or a control condition, while performing a risky decision-making task. The task manipulated, orthogonally, reward magnitude and probability across trials. Three findings emerged. First, reward magnitude had a greater impact on the rate of risky decisions in high social anxiety (HSA) than low social anxiety (LSA) adolescents. Second, reaction times (RTs) were similar during the social stress and the control conditions for the HSA group, whereas the LSA group's RTs differed between conditions. Third, HSA adolescents showed the longest RTs on the most negative trials. These findings suggest that risk-taking in adolescents is modulated by context and reward parameters differentially as a function of social anxiety.

Gender and social rejection as risk factors for engaging in risky sexual behavior among crack/cocaine users.

Crack/cocaine and engagement in risky sexual behavior represent important contributors to the escalation of the HIV infection among women. Several lines of research have emphasized the role of social factors in women's vulnerability for such practices and stressed the importance of understanding such factors to better inform prevention efforts and improve their effectiveness and efficiency. However, few studies have attempted to pinpoint specific social/contextual factors particularly relevant to high-risk populations such as female crack/cocaine users. Extensive previous research has related the experience of social rejection to a variety of negative outcomes including, but not limited to, various forms of psychopathology, self-defeating, and self-harm behavior. Motivated by this research, the current study explored the role of laboratory-induced social rejection in moderating the relationship between gender and risky sexual behavior among a sample of crack/cocaine users (n = 211) at high risk for HIV. The results showed that among women, but not among men, experiencing social rejection was significantly associated with a greater number of sexual partners. Further, experiencing social rejection was not related to the frequency of condom use. Implications for future research, prevention, and treatment are discussed.

What is conscientiousness and how can it be assessed?

Conscientiousness is a personality construct that is a core determinant of health, positive aging, and human capital. A large body of work has contributed to our understanding of this important aspect of personality, but there are multiple conceptual and methodological issues that complicate our understanding of conscientiousness. Toward this end, we review (a) the conceptual standing of conscientiousness as a personality trait, (b) past research focusing on the underlying dimensions of conscientiousness, (c) the nomological network in which conscientiousness is embedded, and (d) the diverse methods that have been used to assess dimensions of conscientiousness. We conclude with recommendations for improving our understanding of the construct of conscientiousness, methods of assessment, and etiological underpinnings of conscientiousness. We believe this article can serve an important role in the larger goal of better understanding conscientiousness and its core role in the health of our society.

A systematic review of fMRI reward paradigms used in studies of adolescents vs. adults: the impact of task design and implications for understanding neurodevelopment.

The neural systems underlying reward-related behaviors across development have recently generated a great amount of interest. Yet, the neurodevelopmental literature on reward processing is marked by inconsistencies due to the heterogeneity of the reward paradigms used, the complexity of the behaviors being studied, and the developing brain itself as a moving target. The present review will examine task design as one source of variability across findings by compiling this literature along three dimensions: (1) task structures, (2) cognitive processes, and (3) neural systems. We start with the presentation of a heuristic neural systems model, the Triadic Model, as a way to provide a theoretical framework for the neuroscience research on motivated behaviors. We then discuss the principles guiding reward task development. Finally, we review the extant developmental neuroimaging literature on reward-related processing, organized by reward task type. We hope that this approach will help to clarify the literature on the functional neurodevelopment of reward-related neural systems, and to identify the role of the experimental parameters that significantly influence these findings.

The prevalence of substance use disorders and psychiatric disorders as a function of psychotic symptoms.

BACKGROUND: Psychotic symptoms represent one of the most severe and functionally impairing components of several psychological disorders. One group with particularly high rates of psychotic symptoms is chronic substance users. However, the literature on psychotic symptoms and substance use is quite narrow and has focused almost exclusively on drug-induced psychosis, neglecting the population of substance users with psychotic symptoms occurring independently of acute drug effects. METHOD: The current study examined demographics, substance dependence, and psychiatric comorbidities among substance users with current (CurrSx), past (PastSx), and no psychotic symptoms (NoSx). Patients (n=685) were sequential admissions to a residential substance use treatment center from 2006 to 2009. RESULTS: Compared to NoSx, those who endorsed CurrSx were significantly more likely to meet criteria for lifetime alcohol dependence and lifetime amphetamine dependence. CurrSx were more likely than PastSx to meet for lifetime cannabis dependence. Additionally, CurrSx were more likely to meet criteria for a comorbid psychiatric disorder compared to NoSx, and evidenced a greater number of current psychiatric disorders. NoSx were less likely than both CurrSx and PastSx to meet criteria for Borderline Personality Disorder. CONCLUSION: Individuals with non-substance induced psychotic symptoms appear to meet criteria for specific substance use disorders and psychiatric disorders at higher rates than those without psychotic symptoms; these effects were most evident for those with current as opposed to past symptoms. Findings suggest that these individuals may need specialized care to address potential psychiatric comorbidities and overall greater severity levels relative to substance users without psychotic symptoms.

Development and preliminary validation of a behavioral task of negative reinforcement underlying risk-taking and its relation to problem alcohol use in college freshmen.

BACKGROUND: A long line of theoretical and empirical evidence implicates negative reinforcement as a process underlying the etiology and maintenance of risky alcohol use behaviors from adolescence through emerging adulthood. However, the bulk of this literature has relied on self-report measures, and there is a notable absence of behavioral modes of assessments of negative reinforcement-based alcohol-related risk-taking. To address this clear gap in the literature, the current study presents the first published data on the reliability and validity of the Maryland Resource for the Behavioral Utilization of the Reinforcement of Negative Stimuli (MRBURNS), which is a modified version of the positive reinforcement-based Balloon Analogue Risk Task (BART). METHODS: Participants included a convenience sample of 116 college freshmen ever regular drinkers (aged 18 to 19) who completed both behavioral tasks; self-report measures of negative reinforcement/avoidance constructs and of positive reinforcement/appetitive constructs to examine convergent validity and discriminant validity, respectively; and self-report measures of alcohol use, problems, and motives to examine criterion validity. RESULTS: The MRBURNS evidenced sound experimental properties and reliability across task trials. In support of convergent validity, risk-taking on the MRBURNS correlated significantly with negative urgency, difficulties in emotion regulation, and depressive and anxiety-related symptoms. In support of discriminant validity, performance on the MRBURNS was unrelated to risk-taking on the BART, sensation seeking, and trait impulsivity. Finally, pertaining to criterion validity, risk-taking on the MRBURNS was related to alcohol-related problems but not heavy episodic alcohol use. Notably, risk-taking on the MRBURNS was associated with negative reinforcement-based but not with positive reinforcement-based drinking motives. CONCLUSIONS: Data from this initial investigation suggest the utility of the MRBURNS as a behavioral measure of negative reinforcement-based risk-taking that can provide a useful complement to existing self-report measures to improve our understanding of the relationship between avoidant reinforcement processes and risky alcohol use.

Neural systems underlying motivated behavior in adolescence: implications for preventive medicine.

OBJECTIVE: Although a time of increased independence and autonomy, adolescence is also a time of vulnerabilities, through increased risk-taking and the emergence of psychopathology. Neurodevelopmental changes during this period may provide a neurobiological basis for this normative rise in deleterious behaviors. Thus, the objective of this review was to identify neurodevelopmental processes underlying the emergence of risk-taking and psychopathology in adolescence, and discuss implications of these findings for prevention. METHOD: This article reviews literature examining developmental and contextual factors influencing neural functioning in systems mediating threat, reward, and cognitive control. This literature is discussed from the perspective of the Triadic Neural Systems Model of motivated behavior. RESULTS: Neuroimaging research suggests that neurodevelopmental and contextual factors both contribute to a shift in the functional equilibrium among the Triadic nodes. This equilibrium shift may contribute to negative outcomes of adolescent risk behavior. Most importantly, the balance of this equilibrium and its sensitivity to social and appetitive contexts may be exploited to facilitate prevention of deleterious outcomes. CONCLUSION: Understanding developmental and contextual factors that influence functioning in motivational neural circuits can inform research on adolescent risk-taking, and may provide targets for novel preventions, for example through the use of incentives to reduce deleterious outcomes.

Biological mechanisms underlying the relationship between stress and smoking: state of the science and directions for future work.

Theories of addiction implicate stress as a crucial mechanism underlying initiation, maintenance, and relapse to cigarette smoking. Examinations of the biological stress systems, including functioning of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), have provided additional insights into the relationship between stress and smoking. To date, convergent data suggests that chronic cigarette smoking is associated with alterations in HPA and ANS functioning; however, less is known about the role of HPA and ANS functioning in smoking initiation and relapse following cessation. In order to organize existing findings and stimulate future research, the current paper summarizes the available literature on the roles of HPA axis and ANS functioning in the relationship between stress and cigarette smoking, highlights limitations within the existing literature, and suggests directions for future research to address unanswered questions in the extant literature on the biological mechanisms underlying the relationship between stress and smoking.

HPA axis response to psychological stress and treatment retention in residential substance abuse treatment: a prospective study.

INTRODUCTION: Substance abuse treatment programs are often characterized by high rates of premature treatment dropout, which increases the likelihood of relapse to drug use. Negative reinforcement models of addiction emphasize an individual's inability to tolerate stress as a key factor for understanding poor substance use treatment outcomes, and evidence indicates that dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis contributes to an individual's inability to respond adaptively to stress. The aim of the current study was to examine whether HPA axis response to stress is predictive of treatment retention among a sample of drug users in residential substance abuse treatment. METHOD: Prospective study assessing treatment retention among 102 individuals enrolled in residential substance abuse treatment. Participants completed two computerized stress tasks, and HPA axis response to stress was measured via salivary cortisol at five time points from baseline (pre-stress) to 30 min post-stress exposure. RESULTS: The main outcome measures were treatment dropout (categorical) and total number of days in treatment (continuous). A significantly higher salivary cortisol response to stress was observed in treatment dropouts compared to treatment completers. Further, Cox proportional hazards survival analyses indicated that a higher peak cortisol response to stress was associated with a shorter number of days to treatment dropout. CONCLUSIONS: Results indicate that a higher salivary cortisol level in response to stress is associated with an inability to remain in substance abuse treatment. These findings are the first to document a biological marker of stress as a predictor of substance abuse treatment dropout, and support the development and implementation of treatments targeting this vulnerability.

The trait of Introversion-Extraversion predicts vulnerability to sleep deprivation.

According to Eysenck's theory of Introversion-Extroversion (I-E), introverts demonstrate higher levels of basal activity within the reticular-thalamic-cortical loop, yielding higher tonic cortical arousal than Extraverts, who are described conversely as chronically under-aroused and easily bored. We hypothesized that higher scores on the trait of Extraversion would be associated with greater declines in psychomotor vigilance performance during prolonged wakefulness. We evaluated the relationship between I-E and overnight psychomotor vigilance performance during 77 h of continuous sleep deprivation in a sample of 23 healthy adult military personnel (19 men; four women), ranging in age from 20 to 35 years. At baseline, volunteers completed the Revised NEO Personality Inventory (NEO PI-R) and completed psychomotor vigilance testing at approximately 10-min intervals from 00:15 to 08:50 hours over three nights of continuous sleep deprivation. In addition, 12 participants received four repeated administrations of caffeine (200 mg) every 2 h each night. Analysis of covariance and stepwise multiple regression analyses showed that, above and beyond the effects of caffeine, higher Extraversion was significantly related to more extensive declines in speed of responding and more frequent attentional lapses, but only for the first overnight testing session. Sub-factors of Extraversion, including Gregariousness and higher Activity level were most predictive of these changes following sleep loss. These findings are consistent with Eysenck's cortico-reticular activation theory of I-E and suggest that individual differences in the trait of Extraversion confer some vulnerability/resistance to the adverse effects of sleep loss on attention and vigilance.

Lack of degradation in visuospatial perception of line orientation after one night of sleep loss.

Sleep deprivation impairs a variety of cognitive abilities including vigilance, attention, and executive function. Although sleep loss has been shown to impair tasks requiring visual attention and spatial perception, it is not clear whether these deficits are exclusively a function of reduced attention and vigilance or if there are also alterations in visuospatial perception. Visuospatial perception and sustained vigilance performance were therefore examined in 54 healthy volunteers at rested baseline and again after one night of sleep deprivation using the Judgment of Line Orientation Test and a computerized test of psychomotor vigilance. Whereas psychomotor vigilance declined significantly from baseline to sleep-deprived testing, scores on the Judgment of Line Orientation did not change significantly. Results suggest that documented performance deficits associated with sleep loss are unlikely to be the result of dysfunction within systems of the brain responsible for simple visuospatial perception and processing of line angles.