Katherine Derbyshire

Measuring “waiting” impulsivity in substance addictions and binge eating disorder in a novel analogue of rodent serial reaction time task

Background Premature responding is a form of motor impulsivity that preclinical evidence has shown to predict compulsive drug seeking but has not yet been studied in humans. We developed a novel translation of the task, based on the rodent 5-choice serial reaction time task, testing premature responding in disorders of drug and natural food rewards. Methods Abstinent alcohol- (n = 30) and methamphetamine-dependent (n = 23) subjects, recreational cannabis users (n = 30), and obese subjects with (n = 30) and without (n = 30) binge eating disorder (BED) were compared with matched healthy volunteers and tested on the premature responding task. Results Compared with healthy volunteers, alcohol- and methamphetamine-dependent subjects and cannabis users showed greater premature responding with no differences observed in obese subjects with or without BED. Current smokers exhibited greater premature responding versus ex-smokers and nonsmokers. Alcohol-dependent subjects also had lower motivation for explicit monetary incentives. A Motivation Index correlated negatively with alcohol use and binge eating severity. Conclusions Premature responding on a novel translation of a serial reaction time task was more evident in substance use disorders but not in obese subjects with or without BED. Lower motivation for monetary incentives linked alcohol use and binge eating severity. Our findings add to understanding the relationship between drug and natural food rewards.

Problematic Internet use and associated risks in a college sample.

OBJECTIVE The Internet is commonly used among young adults; however, Internet use may become a problematic behavior. Past research has examined Internet behavior in young adults and its relationship to other behaviors and health issues, yet further research is needed to gain a more comprehensive understanding of this relationship. METHOD A sample (n=2108) of college students (56.9% female) was examined using a self-report Internet survey concerning demographic characteristics, Internet use, health behaviors, psychosocial functioning, and psychiatric comorbidities. The IAT was used to determine levels of problematic Internet use (limited use (none or almost no use), mild use (typical user), moderate use (occasional problems) and severe use (frequent, serious problems)) and the MINI for testing for psychiatric problems. RESULTS We found that 237 students (12.9%) met criteria for limited Internet use, 1502 (81.8%) for mild Internet use and 98 (5.3%) for moderate to severe Internet use. Variables significantly associated with greater frequency of Internet use included lower Grade Point Average (p=.006), less frequent exercise (p=.018), higher PHQ-9 scores (p<.0001) (indicative of greater depression symptoms) and higher Perceived Stress Scores (p<.0001). CONCLUSIONS These data indicate that moderate to severe Internet use is associated with a range of psychosocial problems in young adults. More research is needed to better understand the relationship between Internet use and physical and mental health, as well as academic variables.

Compulsive Sexual Behavior: A Review of the Literature

Background and Aims Compulsive sexual behavior (CSB) is a common disorder featuring repetitive, intrusive and distressing sexual thoughts, urges and behaviors that negatively affect many aspects of an individual’s life. This article reviews the clinical characteristics of CSB, cognitive aspects of the behaviors, and treatment options. Methods We reviewed the literature regarding the clinical aspects of CSB and treatment approaches. Results The literature review of the clinical aspects of CSB demonstrates that there is likely a substantial heterogeneity within the disorder. In addition, the treatment literature lacks sufficient evidence-based approaches to develop a clear treatment algorithm. Conclusions Although discussed in the psychological literature for years, CSB continues to defy easy categorization within mental health. Further research needs to be completed to understand where CSB falls within the psychiatric nosology.

Obesity and dissociable forms of impulsivity in young adults

OBJECTIVE Obesity is one of the leading causes of preventable morbidity and mortality, and young people are increasingly affected. The aim of this study was to examine relationships between obesity and dissociable forms of impulsivity in young adults. METHODS A group of young adults (511) was recruited from city areas in the United States using media advertisements. These young adults were administered careful and extensive clinical and neurocognitive assessment in order to quantify different aspects of impulsivity (behavioral/phenomenological-, cognitive-, and personality-related measures). Associations between obesity and impulsivity were explored using multivariate analysis of variance and discriminant function analysis. RESULTS 10.8% of the sample was obese, and 21.5% was overweight. Compared to controls, subjects with obesity showed significantly elevated rates of maladaptive gambling behaviors, monetary amounts lost to gambling, nicotine consumption, impulsive action (prolonged stop-signal reaction times in the Stop-Signal Test), and impulsive decision-making (reduced modulation of behavior as a function of risk in the Cambridge Gamble Test). Even accounting for potential confounding variables, obesity was significantly predicted by female gender, older age, more maladaptive gambling behaviors, and worse inhibitory control (stop-signal reaction times). CONCLUSION Obesity is associated with several dissociable forms of impulsivity in young people, especially gambling and impulse dyscontrol. Family doctors should screen for gambling problems in obese young adults. Successful treatment of nicotine dependence in young obese people is likely to require intensive weight management support. Neuropsychological deficits relating to impulsivity occur in obese people in early adulthood, and may represent vulnerability markers rather than being due to chronic untoward metabolic effects on brain function.

Skin picking disorder in university students: health correlates and gender differences

OBJECTIVE This study sought to examine the prevalence of skin picking disorder (SPD) in a university sample and assess associated physical and mental health correlates. METHODS A 54-item anonymous, voluntary survey was distributed via random email generation to a sample of 6000 university students. Current psychological and physical status was assessed, along with academic performance. Positive screens for SPD were determined based upon individuals meeting full proposed DSM-V criteria. RESULTS A total of 1916 participants (31.9%; mean age 22.7 ± 5.1; 58.1% female) responded and were included in the analysis. The overall prevalence of SPD was 4.2% (females=5.8%; males=2.0%). SPD was associated with significantly higher lifetime rates of affective, anxiety, eating, substance use and impulse control disorders. Men with SPD had significantly higher BMI ratings and perceived themselves as significantly less attractive to others while women had significantly higher depressive symptoms. CONCLUSION SPD is common in both genders and is associated with significant mental and physical health detriments, including higher levels of stress, more psychiatric comorbidity and poorer perceived health. Academic institutions, clinicians and public health officials should be aware of the multimodal presentation of SPD and screen for it in primary care and dermatologic settings.

Mental Health and Clinical Correlates in Lesbian, Gay, Bisexual, and Queer Young Adults

Abstract Objective: This study examined the prevalence of mental health disorders and their clinical correlates in a university sample of lesbian, gay, bisexual, and queer (LGBQ) students. Participants: College students at a large public university. Methods: An anonymous, voluntary survey was distributed via random e-mail generation to university students during April and May of 2011. LGBQ students were compared with their heterosexual counterparts on psychological and physical status as well as academic performance. Results: LGBQ students reported worse depressive symptoms, higher levels of perceived stress, considered themselves less attractive, and were more likely to be overweight. LGBQ students were significantly more likely to report histories of affective, substance use, and certain anxiety disorders as well as compulsive sexual behavior and compulsive buying. Conclusions: The higher rates of many psychiatric conditions among LGBQ students underscore the need for universities to provide LGBQ students a nonjudgmental environment to discuss sexual orientation and health issues.

Prevalence and characteristics of compulsive buying in college students.

Compulsive buying (CB) is a potentially devastating problem involving repetitive urges to shop and uncontrolled spending behaviors. Prevalence of CB in the general population has been estimated at 5.8%. This epidemiological study aims to better understand the prevalence and characteristics of college students who meet criteria for CB. During the spring of 2011, an online survey examining CB (using a clinically validated screening instrument, the Minnesota Impulse Disorders Interview), stress and mood states, psychiatric comorbidity, and psychosocial functioning was emailed to 2108 University students. Overall survey response rate was 35.1% (n=2108). Our data indicated that 3.6% (n=67) of college students surveyed met criteria for CB with significantly more women affected (4.4%, n=48) than men (2.5%, n=19). Relative to students not meeting criteria for CB, college students who met criteria for CB endorsed significantly greater psychiatric comorbidity, lower grade point averages, increased stress, and poorer physical health. Presence of CB is likely associated with a variety of problems in college students. These data may warrant increased screening of CB in college students to establish early interventions.

Risk taking in disorders of natural and drug rewards: neural correlates and effects of probability, valence and magnitude

Pathological behaviors toward drugs and food rewards have underlying commonalities. Risk-taking has a fourfold pattern varying as a function of probability and valence leading to the nonlinearity of probability weighting with overweighting of small probabilities and underweighting of large probabilities. Here we assess these influences on risk-taking in patients with pathological behaviors toward drug and food rewards and examine structural neural correlates of nonlinearity of probability weighting in healthy volunteers. In the anticipation of rewards, subjects with binge eating disorder show greater risk-taking, similar to substance-use disorders. Methamphetamine-dependent subjects had greater nonlinearity of probability weighting along with impaired subjective discrimination of probability and reward magnitude. Ex-smokers also had lower risk-taking to rewards compared with non-smokers. In the anticipation of losses, obesity without binge eating had a similar pattern to other substance-use disorders. Obese subjects with binge eating also have impaired discrimination of subjective value similar to that of the methamphetamine-dependent subjects. Nonlinearity of probability weighting was associated with lower gray matter volume in dorsolateral and ventromedial prefrontal cortex and orbitofrontal cortex in healthy volunteers. Our findings support a distinct subtype of binge eating disorder in obesity with similarities in risk-taking in the reward domain to substance use disorders. The results dovetail with the current approach of defining mechanistically based dimensional approaches rather than categorical approaches to psychiatric disorders. The relationship to risk probability and valence may underlie the propensity toward pathological behaviors toward different types of rewards.

Prevalence and correlates of being overweight or obese in college.

Recent statistics indicate that over one-third of college students are currently overweight or obese, however, the impact of weight in this population from academic and psychiatric perspectives is not fully understood. This study sought to examine the prevalence of overweight and obesity in college students and its association with stress, mental health disorders and academic achievement. A total of 1765 students completed the College Student Computer User Survey (CSCUS) online at a large Midwestern United States University. Responders were classified by weight as normal, overweight or obese based on body mass index. Data were stratified by sex, with cross-tabulation and t-tests, one-way analysis of variance, and logistic regression for analysis. A total of 492 (27.9%) students were overweight (20.2%; range 25.01-29.98) or obese (7.7%; range 30.04-71.26). Overweight and obesity were associated with significantly lower overall academic achievement, more depressive symptoms, and using diet pills for weight loss. Obese males had significantly higher rates of lifetime trichotillomania while overweight and obese females reported higher rates of panic disorder. Higher educational institutions should be aware of the significant burden associated with overweight and obesity in students, and of the differing demographic and clinical associations between overweight or obesity in men and women.

Impact of ADHD symptoms on clinical and cognitive aspects of problem gambling.

BACKGROUND Problem gambling is common across cultures, and has been conceptualized in terms of impulsivity. While elevated rates of attention deficit hyperactivity disorder (ADHD) have been observed in problem gamblers, the relationship between these two conditions, and other dissociable forms of impulsivity, has received little research attention. METHODS N=126 non-treatment seeking young adults with problem gambling were recruited from the community, and were grouped according to the presence or absence of probable current ADHD. Clinical and cognitive measures pertaining to impulsivity were collected via detailed psychiatric assessment, questionnaires, and computerized neuropsychological tests. These variables were compared between groups. RESULTS Probable current ADHD was identified in 21.4% of the sample, and was associated with earlier age at onset of gambling behaviors, higher Barratt impulsivity scores (all three subscales), greater caffeine intake, worse response inhibition (Stop-Signal Test), and impaired decision-making (greater proportion of points gambled, Cambridge Gamble Test). Problem gamblers with and without ADHD did not differ on demographic characteristics or the rate of other psychiatric disorders, depression scores, nicotine and alcohol consumption, and body mass index. No significant group differences were found for general response speed, working memory, or executive planning. CONCLUSIONS ADHD is common in young adults with dysfunctional gambling behaviors and is associated with elevated questionnaire and cognitive based measures of impulsivity, along with heightened caffeine use. Future work should study the causal nature between these factors and the treatment implications of these findings.