A targeted review of the neurobiology and genetics of behavioural addictions: an emerging area of research

Anesthetic implications of recreational drug use

PURPOSE

As the use of recreational drugs increases, the likelihood of an anesthesiologist perioperatively encountering patients using or addicted to these drugs will also increase.

PRINCIPAL FINDINGS

Addicted patients may present for anesthetic care in a variety of circumstances in everyday elective surgeries or in acute or life-saving situations, such as emergency Cesarean delivery or trauma surgery. Therefore, it is important for anesthesiologists to know about the most common illicit drugs being used, their clinical presentation and side effects, and the anesthetic options that are beneficial or detrimental to these patients. The most frequently used illicit substances, apart from alcohol and tobacco, are cannabis, cocaine, heroin, prescription opioids, methamphetamine, and hallucinogens. When planning anesthetic care, it is important for anesthesiologists to understand the effects of these agents, including various drug interactions, to predict tolerance to some anesthetic agents, to recognize drug withdrawal signs and symptoms, and to be prepared to manage all these factors in the perioperative period.

CONCLUSIONS

For optimal patient care through the perioperative period, it is critical to obtain information about patient drug use and other associated treatment in order to construct an appropriate anesthetic plan, including specific considerations during surgery, emergence, and in the postanesthesia care unit.

Clinical neuropsychiatric considerations regarding nonsubstance or behavioral addictions

Over the past several decades, non-substance-use behaviors like gambling, gaming, and sex have received greater consideration as possible foci of addictions. In this article, I will review the recent history and current status of non-substance or behavioral addictions. A main focus will involve gambling and gambling disorder, given that the latter is currently the sole non-substance addictive disorder described in the main text of the current (fifth) edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Internet gaming disorder, currently in the DSM-5 section addressing conditions that may need additional research, will also be considered, as will the concept of Internet addiction. Compulsive sexual behaviors (including problematic pornography use) will be considered, particularly with respect to how behavioral addictions may be considered in the forthcoming 11th edition of the International Classification of Diseases (ICD-11).

Neurobiological findings related to Internet use disorders

In the last 10 years, numerous neurobiological studies have been conducted on Internet addiction or Internet use disorder. Various neurobiological research methods - such as magnetic resonance imaging; nuclear imaging modalities, including positron emission tomography and single photon emission computed tomography; molecular genetics; and neurophysiologic methods - have made it possible to discover structural or functional impairments in the brains of individuals with Internet use disorder. Specifically, Internet use disorder is associated with structural or functional impairment in the orbitofrontal cortex, dorsolateral prefrontal cortex, anterior cingulate cortex, and posterior cingulate cortex. These regions are associated with the processing of reward, motivation, memory, and cognitive control. Early neurobiological research results in this area indicated that Internet use disorder shares many similarities with substance use disorders, including, to a certain extent, a shared pathophysiology. However, recent studies suggest that differences in biological and psychological markers exist between Internet use disorder and substance use disorders. Further research is required for a better understanding of the pathophysiology of Internet use disorder.

Interpersonal violence, early life adversity, and suicidal behavior in hypersexual men

Background and aims There are significant gaps in knowledge regarding the role of childhood adversity, interpersonal violence, and suicidal behavior in hypersexual disorder (HD). The aim of this study was to investigate interpersonal violence in hypersexual men compared with healthy volunteers and the experience of violence in relation to suicidal behavior. Methods This case-control study includes 67 male patients with HD and 40 healthy male volunteers. The Childhood Trauma Questionnaire - Short Form (CTQ-SF) and the Karolinska Interpersonal Violence Scale (KIVS) were used for assessing early life adversity and interpersonal violence in childhood and in adult life. Suicidal behavior (attempts and ideation) was assessed with the Mini-International Neuropsychiatric Interview (version 6.0) and the Montgomery-Åsberg Depression Rating Scale - Self-rating. Results Hypersexual men reported more exposure to violence in childhood and more violent behavior as adults compared with healthy volunteers. Suicide attempters (n = 8, 12%) reported higher KIVS total score, more used violence as a child, more exposure to violence as an adult as well as higher score on CTQ-SF subscale measuring sexual abuse (SA) compared with hypersexual men without suicide attempt. Discussion Hypersexuality was associated with interpersonal violence with higher total scores in patients with a history of suicide attempt. The KIVS subscale exposure to interpersonal violence as a child was validated using the CTQ-SF but can be complemented with questions focusing on SA for full assessment of early life adversity. Conclusion Childhood adversity is an important factor in HD and interpersonal violence might be related to suicidal behavior in hypersexual men.

Neural correlate of Internet use in patients undergoing psychological treatment for Internet addiction

BACKGROUND

The new version of Diagnostic and Statistical Manual of Mental Disorders (DSM-5th) proposed the Internet Gaming Disorder for the diagnosis of Internet addiction (IA) considering the neurobiological evidence of the craving.

AIMS

The aim was to test the neural correlate in response to the Internet cue in patients with IA.

METHODS

Sixteen males with IA diagnosis (clinical group) and 14 healthy male (control group) were recruited for an experimental visual task composed of Internet images and emotional images. During the visual presentation of Internet cue, electroencefalographic data were recorded using Net Station 4.5.1 with a 256-channels HydroCel Geodesic Sensor Net. Event-related potential (ERP) components and low-resolution electromagnetic tomography (sLoreta) were analysed.

RESULTS

sLoreta analyses showed that patients from the clinical group presented a higher primary somatosensorial cortex and lower paralimbic, temporal and orbito-frontal activation in response to both Internet and emotional images compared to those of the control group.

CONCLUSIONS

These results suggest that clinically recognized pathological use of Internet could be linked to dissociative symptoms.

Resting-State Functional Connectivity in the Human Connectome Project: Current Status and Relevance to Understanding Psychopathology

A key tenet of modern psychiatry is that psychiatric disorders arise from abnormalities in brain circuits that support human behavior. Our ability to examine hypotheses around circuit-level abnormalities in psychiatric disorders has been made possible by advances in human neuroimaging technologies. These advances have provided the basis for recent efforts to develop a more complex understanding of the function of brain circuits in health and of their relationship to behavior-providing, in turn, a foundation for our understanding of how disruptions in such circuits contribute to the development of psychiatric disorders. This review focuses on the use of resting-state functional connectivity MRI to assess brain circuits, on the advances generated by the Human Connectome Project, and on how these advances potentially contribute to understanding neural circuit dysfunction in psychopathology. The review gives particular attention to the methods developed by the Human Connectome Project that may be especially relevant to studies of psychopathology; it outlines some of the key findings about what constitutes a brain region; and it highlights new information about the nature and stability of brain circuits. Some of the Human Connectome Project's new findings particularly relevant to psychopathology-about neural circuits and their relationships to behavior-are also presented. The review ends by discussing the extension of Human Connectome Project methods across the lifespan and into manifest illness. Potential treatment implications are also considered.

Neurobiological correlates of internet gaming disorder: Similarities to pathological gambling

The number of massively multiplayer online games (MMOs) is on the rise worldwide along with the fascination that they inspire. Problems occur when the use of MMOs becomes excessive at the expense of other life domains. Although not yet formally included as disorder in common diagnostic systems, internet gaming disorder (IGD) is considered a "condition for further study" in section III of the DSM-5. The current review aims to provide an overview of cognitive and neurobiological data currently available on IGD, with a particular focus on impulsivity, compulsivity, and sensitivity to reward and punishment. Additionally, we also compare these findings on IGD with data from studies on pathological gambling (PG)-so far the only condition officially classified as a behavioral addiction in the DSM-5. Multiple similarities have been observed in the neurobiology of IGD and PG, as measured by alterations in brain function and behavior. Both patients with IGD and those with PG exhibited decreased loss sensitivity; enhanced reactivity to gaming and gambling cues, respectively; enhanced impulsive choice behavior; aberrant reward-based learning; and no changes in cognitive flexibility. In conclusion, the evidence base on the neurobiology of gaming and gambling disorders is beginning to illuminate the similarities between the two. However, as only a few studies have addressed the neurobiological basis of IGD, and some of these studies suffer from significant limitations, more research is required before IGD's inclusion as a second behavioral addiction in the next versions of the ICD and DSM can be justified.

Should compulsive sexual behavior be considered an addiction?

AIMS

To review the evidence base for classifying compulsive sexual behavior (CSB) as a non-substance or 'behavioral' addiction.

METHODS

Data from multiple domains (e.g. epidemiological, phenomenological, clinical, biological) are reviewed and considered with respect to data from substance and gambling addictions.

RESULTS

Overlapping features exist between CSB and substance use disorders. Common neurotransmitter systems may contribute to CSB and substance use disorders, and recent neuroimaging studies highlight similarities relating to craving and attentional biases. Similar pharmacological and psychotherapeutic treatments may be applicable to CSB and substance addictions, although considerable gaps in knowledge currently exist.

CONCLUSIONS

Despite the growing body of research linking compulsive sexual behavior (CSB) to substance addictions, significant gaps in understanding continue to complicate classification of CSB as an addiction.

Cognitive behavioral therapy for compulsive buying behavior: Predictors of treatment outcome

BACKGROUND

Compulsive buying behavior (CBB) is receiving increasing consideration in both consumer and psychiatric-epidemiological research, yet empirical evidence on treatment interventions is scarce and mostly from small homogeneous clinical samples.

OBJECTIVES

To estimate the short-term effectiveness of a standardized, individual cognitive behavioral therapy intervention (CBT) in a sample of n=97 treatment-seeking patients diagnosed with CBB, and to identify the most relevant predictors of therapy outcome.

METHOD

The intervention consisted of 12 individual CBT weekly sessions, lasting approximately 45minutes each. Data on patients' personality traits, psychopathology, sociodemographic factors, and compulsive buying behavior were used in our analysis.

RESULTS

The risk (cumulative incidence) of poor adherence to the CBT program was 27.8%. The presence of relapses during the CBT program was 47.4% and the dropout rate was 46.4%. Significant predictors of poor therapy adherence were being male, high levels of depression and obsessive-compulsive symptoms, low anxiety levels, high persistence, high harm avoidance and low self-transcendence.

CONCLUSION

Cognitive behavioral models show promise in treating CBB, however future interventions for CBB should be designed via a multidimensional approach in which patients' sex, comorbid symptom levels and the personality-trait profiles play a central role.

Problematic Internet use, well-being, self-esteem and self-control: Data from a high-school survey in China

Given the prevalence of Internet use among youth, there is concern that a subset of Internet-using youth may exhibit problematic or addictive patterns of Internet use. The present study examines the association between problematic Internet use (PIU), demographic variables, and health-related measures among Chinese adolescents. Survey data from 1552 adolescents (male=653, mean age=15.43years) from Jilin Province, China, were collected. According to the Young Diagnostic Questionnaire for Internet Addiction (YDQ), 77.8% (n=1207), 16.8% (n=260), and 5.5% (n=85) showed adaptive, maladaptive, and problematic Internet use, respectively. Multinomial logistic regression analysis revealed that gender and family income per month differed between youth showing problematic and adaptive patterns of Internet use. Well-being, self-esteem, and self-control were related to severity of problematic Internet use, with greater severity typically associated with poorer measures in each domain. The findings that severity of problematic Internet use is associated with specific socio-demographic features and temperamental and well-being measures suggest that specific groups of youth may be particularly vulnerable to developing problematic Internet use. Early prevention/intervention programs targeting at-risk groups may help improve public health.

Chronic D2/3 agonist ropinirole treatment increases preference for uncertainty in rats regardless of baseline choice patterns

D_2/3 receptor agonists are effective treatments for Parkinson's disease (PD), but can precipitate impulse control disorders (ICDs) including gambling disorder (GD). The neurobiological mechanisms underlying this devastating side-effect of dopamine agonist replacement therapy (DRT), and any dependence on the dopamine depletion caused by PD, are unclear. It is also unclear whether previous biases towards risk or uncertainty are a risk factor for developing these ICDs. We investigated whether chronic D_2/3 agonist administration (5 mg/kg/day ropinirole for 28 days) altered performance of a rat model of gambling-like behaviour, the rodent betting task (rBT), and examined if baseline behaviour predicted this behavioural change. The rBT captures individual differences in subjective preference for uncertain outcomes: animals choose between guaranteed or probabilistic reinforcement of equal expected value. Chronic ropinirole dramatically increased selection of the uncertain option in two-thirds of animals, regardless of baseline preferences. The effect on choice in the rBT was replicated in a dorsolateral striatal 6-hydroxydopamine (6-OHDA) rat model of early PD. These studies are the first to look at individual differences in response to chronic, rather than pulsatile, dosing of DRT in a rodent model of gambling behaviour. These findings suggest that DRT-induced PG may stem from increases in subjective valuation of uncertainty. Such symptoms likely arise because of changes in dopaminergic striatal signalling caused by DRT rather than from an interaction between pre-morbid behaviours or PD itself.

Compulsive buying disorder clustering based on sex, age, onset and personality traits

In spite of the revived interest in compulsive buying disorder (CBD), its classification into the contemporary nosologic systems continues to be debated, and scarce studies have addressed heterogeneity in the clinical phenotype through methodologies based on a person-centered approach.

OBJECTIVES

To identify empirical clusters of CBD employing personality traits, as well as patients' sex, age and the age of CBD onset as indicators.

METHODS

An agglomerative hierarchical clustering method defining a combination of the Schwarz Bayesian Information Criterion and log-likelihood was used.

RESULTS

Three clusters were identified in a sample of n=110 patients attending a specialized CBD unit a) "male compulsive buyers" reported the highest prevalence of comorbid gambling disorder and the lowest levels of reward dependence; b) "female low-dysfunctional" mainly included employed women, with the highest level of education, the oldest age of onset, the lowest scores in harm avoidance and the highest levels of persistence, self-directedness and cooperativeness; and c) "female highly-dysfunctional" with the youngest age of onset, the highest levels of comorbid psychopathology and harm avoidance, and the lowest score in self-directedness.

CONCLUSION

Sociodemographic characteristics and personality traits can be used to determine CBD clusters which represent different clinical subtypes. These subtypes should be considered when developing assessment instruments, preventive programs and treatment interventions.

Compulsive Buying Behavior: Clinical Comparison with Other Behavioral Addictions

Compulsive buying behavior (CBB) has been recognized as a prevalent mental health disorder, yet its categorization into classification systems remains unsettled. The objective of this study was to assess the sociodemographic and clinic variables related to the CBB phenotype compared to other behavioral addictions. Three thousand three hundred and twenty four treatment-seeking patients were classified in five groups: CBB, sexual addiction, Internet gaming disorder, Internet addiction, and gambling disorder. CBB was characterized by a higher proportion of women, higher levels of psychopathology, and higher levels in the personality traits of novelty seeking, harm avoidance, reward dependence, persistence, and cooperativeness compared to other behavioral addictions. Results outline the heterogeneity in the clinical profiles of patients diagnosed with different behavioral addiction subtypes and shed new light on the primary mechanisms of CBB.

Addiction in Extreme Sports: An Exploration of Withdrawal States in Rock Climbers

Background and aims Extreme sports athletes are often labeled "adrenaline junkies" by the media, implying they are addicted to their sport. Research suggests during abstinence these athletes may experience withdrawal states characteristic of individuals with an addiction (Celsi, Rose, & Leigh, 1993; Franken, Zijlstra, & Muris, 2006; Willig, 2008). Despite this notion, no research has directly explored withdrawal experiences of extreme sports athletes. Methods Using semi-structured interviews, we explored withdrawal experiences of high (n = 4) and average-ability (n = 4) male rock climbers during periods of abstinence. We investigated the psychological and behavioral aspects of withdrawal, including craving, anhedonia, and negative affect; and differences in the frequency and intensity of these states between groups. Results Deductive content analysis indicated support for each of the three categories of anhedonia, craving, and negative affect. Consistent with existing substance addiction literature, high-ability climbers recalled more frequent and intense craving states and negative affect during abstinence compared with average-ability climbers. No differences in anhedonic symptoms between high and average-ability participants were found. Conclusions Rock climbing athletes appear to experience withdrawal symptoms when abstinent from their sport comparable to individuals with substance and behavioral addictions. The implications of these findings and suggestions for future research are discussed.

How Much Is Too Much to Pay for Internet Access? A Behavioral Economic Analysis of Internet Use

The popularity of online recreational activities, such as social networking, has dramatically increased the amount of time spent on the Internet. Excessive or inappropriate use of the Internet can result in serious adverse consequences. The current study used a behavioral economic task to determine if the amount of time spent online by problematic and nonproblematic users can be modified by price. The Internet Purchase Task was used to determine how much time undergraduate students (N=233) would spend online at 13 different prices. Despite high demand for Internet access when access was free, time spent online by both problematic and nonproblematic users decreased dramatically, even at low prices. These results suggest that the amount of time spent online may be modified by having a tangible cost associated with use, whereas having free access to the Internet may encourage excessive, problematic use.

Psychiatric Conditions in Parkinson Disease: A Comparison With Classical Psychiatric Disorders

Psychiatric conditions often complicate the outcome of patients affected by Parkinson disease (PD), but they differ from classical psychiatric disorders in terms of underlying biological mechanisms, clinical presentation, and treatment response. The purpose of the present review is to illustrate the biological and clinical aspects of psychiatric conditions associated with PD, with particular reference to the differences with respect to classical psychiatric disorders. A careful search of articles on main databases was performed in order to obtain a comprehensive review about the main psychiatric conditions associated with PD. A manual selection of the articles was then performed in order to consider only those articles that concerned with the topic of the review. Psychiatric conditions in patients with PD present substantial differences with respect to classical psychiatric disorders. Their clinical presentation does not align with the symptom profiles represented by Diagnostic and Statistical Manual for Mental Disorders and International Classification of Diseases. Furthermore, psychiatry treatment guidelines are of poor help in managing psychiatric symptoms of patients with PD. Specific diagnostic tools and treatment guidelines are needed to allow early diagnosis and adequate treatment of psychiatric conditions in comorbidity with PD.

Neural and psychological underpinnings of gambling disorder: A review

Gambling disorder affects 0.4 to 1.6% of adults worldwide, and is highly comorbid with other mental health disorders. This article provides a concise primer on the neural and psychological underpinnings of gambling disorder based on a selective review of the literature. Gambling disorder is associated with dysfunction across multiple cognitive domains which can be considered in terms of impulsivity and compulsivity. Neuroimaging data suggest structural and functional abnormalities of networks involved in reward processing and top-down control. Gambling disorder shows 50-60% heritability and it is likely that various neurochemical systems are implicated in the pathophysiology (including dopaminergic, glutamatergic, serotonergic, noradrenergic, and opioidergic). Elevated rates of certain personality traits (e.g. negative urgency, disinhibition), and personality disorders, are found. More research is required to evaluate whether cognitive dysfunction and personality aspects influence the longitudinal course and treatment outcome for gambling disorder. It is hoped that improved understanding of the biological and psychological components of gambling disorder, and their interactions, may lead to improved treatment approaches and raise the profile of this neglected condition.

Behavioral addictions in addiction medicine: from mechanisms to practical considerations

Recent progress has been made in our understanding of nonsubstance or "behavioral" addictions, although these conditions and their most appropriate classification remain debated and the knowledge basis for understanding the pathophysiology of and treatments for these conditions includes important gaps. Recent developments include the classification of gambling disorder as a "Substance-Related and Addictive Disorder" in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and proposed diagnostic criteria for Internet Gaming Disorder in Section 3 of DSM-5. This chapter reviews current neuroscientific understandings of behavioral addictions and the potential of neurobiological data to assist in the development of improved policy, prevention, and treatment efforts.

Neuroscience of Internet Pornography Addiction: A Review and Update

Many recognize that several behaviors potentially affecting the reward circuitry in human brains lead to a loss of control and other symptoms of addiction in at least some individuals. Regarding Internet addiction, neuroscientific research supports the assumption that underlying neural processes are similar to substance addiction. The American Psychiatric Association (APA) has recognized one such Internet related behavior, Internet gaming, as a potential addictive disorder warranting further study, in the 2013 revision of their Diagnostic and Statistical Manual. Other Internet related behaviors, e.g., Internet pornography use, were not covered. Within this review, we give a summary of the concepts proposed underlying addiction and give an overview about neuroscientific studies on Internet addiction and Internet gaming disorder. Moreover, we reviewed available neuroscientific literature on Internet pornography addiction and connect the results to the addiction model. The review leads to the conclusion that Internet pornography addiction fits into the addiction framework and shares similar basic mechanisms with substance addiction. Together with studies on Internet addiction and Internet Gaming Disorder we see strong evidence for considering addictive Internet behaviors as behavioral addiction. Future research needs to address whether or not there are specific differences between substance and behavioral addiction.

Altered cardiorespiratory coupling in young male adults with excessive online gaming

INTRODUCTION

This study aimed to investigate changes in heart rate variability and cardiorespiratory coupling in male college students with problematic Internet use (PIU) excessive gaming type during action video game play to assess the relationship between PIU tendency and central autonomic regulation.

METHOD

Electrocardiograms and respiration were simultaneously recorded from 22 male participants with excessive online gaming and 22 controls during action video game play. Sample entropy (SampEn) was computed to assess autonomic regularity, and cross-SampEn was calculated to quantify autonomic coordination.

RESULTS

During video game play, reduced cardiorespiratory coupling (CRC) was observed in individuals with PIU excessive gaming type compared with controls, implicating central autonomic dysregulation. The PIU tendency was associated with the severity of autonomic dysregulation.

CONCLUSION

These findings indicate impaired CRC in PIU excessive gaming type, which may reflect alterations of central inhibitory control over autonomic responses to pleasurable online stimuli.

The prefrontal dysfunction in individuals with Internet gaming disorder: a meta-analysis of functional magnetic resonance imaging studies

With the advancement in high-resolution magnetic resonance imaging (MRI) technology and automated analysis, studies on functional MRI (fMRI) made it possible to identify the functional activity of brain in vivo in individuals with Internet gaming disorder (IGD), and to explore the underpinning neuroscience basis of IGD. Yet, no available literature has systemically reviewed the fMRI studies of IGD using meta-analyses. This study reviewed 61 candidate articles and finally selected 10 qualified voxel-wise whole-brain analysis studies for performing a comprehensive series of meta-analyses employing effect size signed differential mapping approach. Compared with healthy controls, subjects with IGD showed a significant activation in the bilateral medial frontal gyrus (MFG) and the left cingulate gyrus, as well as the left medial temporal gyrus and fusiform gyrus. Furthermore, the on-line time of IGD subjects was positively correlated with activations in the left MFG and the right cingulated gyrus. These findings implicate the important role of dysfunctional prefrontal lobe in the neuropathological mechanism of IGD. Considering the overlapped role of prefrontal lobe in the reward and self-regulatory system, our results provided supportive evidence for the reclassification of IGD as a behavioural addiction.

[Richard Freiherr v. Krafft-Ebing and Sigmund Freud--discourse on the "normality" and "perversion" of human sexuality at the close of the 19th century and the beginning of the 20th century]

Sexuality has been defined a central feature of personal identity since the epoch of enlightenment and has gradually become a decisive issue also in societal and political terms. A major transfer from religion and religious institutions to medicine and medical experts and later on to neuropsychiatrists has to be underlined in the primary position to assess "normal" and "deviant" manifestations of sexuality. Richard Freiherr von Krafft-Ebing and Sigmund Freund play an eminent role in this "discourse on sexuality" (M. Foucault) during the nineteenth and beginning twentieth century on the way to modern sexology. Within this overarching context Krafft-Ebing's and Freud's theoretical conceptualizations of sexuality and perversion will be sketched and basic clinical and societal implications there out will be discussed.

Obesity and gambling: neurocognitive and clinical associations

OBJECTIVE

Research on health correlates in gamblers has found an association between gambling and obesity. The neurocognitive underpinnings of impulsivity may be useful targets for understanding and ultimately treating individuals with both gambling and obesity problems.

METHOD

207 non-treatment seeking young adults (18-29 years) with subsyndromal gambling disorder were recruited from the community. Subjects were grouped according to weight ('normal weight' BMI<25, 'overweight' BMI≥25; or 'obese' BMI≥30). Measures relating to gambling behaviour and objective computerized neurocognitive measures were collected.

RESULTS

Of the 207 subjects, 22 (10.6%) were obese and 49 (23.7%) were overweight. The obese gamblers consumed more nicotine (packs per day equivalent) and reported losing more money per week to gambling. Obese gamblers exhibited significant impairments in terms of reaction times for go trials on the stop-signal test (SST), quality of decision making and risk adjustment on the Cambridge Gamble Test (CGT), and sustained attention on the rapid visual information processing task (RVP).

CONCLUSION

Obesity was associated with decision making and sustained attention impairments in gamblers, along with greater monetary loss due to gambling. Future work should use longitudinal designs to examine the temporal relationship between these deficits, weight, other impulsive behaviour, and functional impairment.

Examining the psychometric properties of the Yale-Brown Obsessive-Compulsive Scale in a sample of compulsive pornography users

OBJECTIVE

The current study evaluated several psychometric properties of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) (Goodman et al., 1989) adapted for compulsive sexual behavior (CSB) in a sample of 103 men seeking treatment at a private and a public university clinic in the United States.

METHOD

Measures of mental health functioning were collected from patients on two separate appointments: the initial screening and the follow-up appointment.

RESULTS

All patients reported using pornography compulsively, and approximately half of the sample also reported a history of having frequent anonymous sex with strangers. Results found that the adapted Y-BOCS had good internal consistency reliability, moderate mean inter-item correlations, and good test-retest reliability. Results from a multiple regression analysis also found that affect dysregulation (depression and anxiety), particularly among single, impaired men, was significantly associated with more severe sexual obsessive and compulsive features. Approximately 94% of the sample met criteria for at least one psychiatric disorder, and 57% of men met criteria for two or more psychiatric disorders.

CONCLUSIONS

Findings from the current study suggest the CSB-Y-BOCS is a reliable measure of obsessive and compulsive symptoms associated with CSB, and clinicians and researchers could use this scale to aid in the assessment and treatment of problematic sexual behaviors.

Low copulatory activity in selectively bred Sardinian alcohol-nonpreferring (sNP) relative to alcohol-preferring (sP) rats

BACKGROUND

There is a growing consensus that similar neural mechanisms are involved in the reinforcing properties of natural rewards, like food and sex, and drugs of abuse. Rat lines selectively bred for high and low oral alcohol intake and preference have been useful for understanding factors contributing to excessive alcohol intake and may constitute proper animal models for investigating the neurobiological basis of natural rewarding stimuli.

METHODS

The present study evaluated copulatory behavior in alcohol and sexually naïve Sardinian alcohol-preferring (sP) and -nonpreferring (sNP) male rats in three consecutive copulatory behavior tests.

RESULTS

The main finding was that, under the conditions used in this study, sNP rats were sexually inactive relative to sP rats. To gain more information about the sexual behavior in sP rats, Wistar rats were included as an external reference strain. Only minor differences between sP and Wistar rats were revealed.

CONCLUSIONS

The reason behind the low copulatory activity of sNP rats remains to be elucidated, but may in part be mediated by innate differences in brain transmitter systems. The comparison between sP and Wistar rats may also suggest that the inherent proclivity to excessive alcohol drinking in sP rats may mainly be dependent on its anxiolytic properties, as previously proposed, and not changes in the reward system.

Co-occurrence of alcohol use disorder and behavioral addictions: relevance of impulsivity and craving

PURPOSE

The aims of the study were to evaluate the occurrence of behavioral addictions (BAs) in alcohol use disorder (AUD) subjects and to investigate the role of impulsivity, personality dimensions and craving.

METHODS

95 AUD outpatients (DSM-5) and 140 homogeneous controls were assessed with diagnostic criteria and specific tests for gambling disorder, compulsive buying, sexual, internet and physical exercise addictions, as well as with the Barratt Impulsiveness Scale (BIS-11) and Temperamental and Character Inventory-Revised (TCI-R). The Obsessive Compulsive Drinking Scale (OCDS) and Visual Analogue Scale for craving (VASc) were also administered to the AUD sample.

RESULTS

28.4% (n=27) of AUD subjects had at least one BA, as compared to 15% (n=21) of controls (χ(2)=6.27; p=.014). In AUD subjects, direct correlations between BIS-11 and Compulsive Buying Scale (CBS), Internet Addiction Disorder test (IAD), Exercise Addiction Inventory-Short Form (EAI-SF) scores (p<.01), between OCDS obsessive and CBS and VASc and CBS, IAD scores (p<.003), were found. BIS-11 (t=-2.36; p=.020), OCDS obsessive (Z=-4.13; p<.001), OCDS compulsive (Z=-2.12; p=.034) and VASc (Z=-4.94; p<.001) scores were higher in AUD subjects with co-occurring BAs. The occurrence of BAs was associated with higher impulsivity traits (BIS-11 scores; OR=1.08; p=.012) and higher craving levels (VASc scores; OR=2.48; p<.001).

CONCLUSIONS

Our findings emphasize a significant rate of co-occurrence of BAs in AUD. High levels of impulsivity and craving for alcohol seem to be associated with other addictive behaviors.

Differences in functional connectivity between alcohol dependence and internet gaming disorder

INTRODUCTION

Internet gaming disorder (IGD) and alcohol dependence (AD) have been reported to share clinical characteristics including craving and over-engagement despite negative consequences. However, there are also clinical factors that differ between individuals with IGD and those with AD in terms of chemical intoxication, prevalence age, and visual and auditory stimulation.

METHODS

We assessed brain functional connectivity within the prefrontal, striatum, and temporal lobe in 15 patients with IGD and in 16 patients with AD. Symptoms of depression, anxiety, and the attention deficit hyperactivity disorder were assessed in patients with IGD and in patients with AD.

RESULTS

Both AD and IGD subjects have positive functional connectivity between the dorsolateral prefrontal cortex (DLPFC), cingulate, and cerebellum. In addition, both groups have negative functional connectivity between the DLPFC and the orbitofrontal cortex. However, the AD subjects have positive functional connectivity between the DLPFC, temporal lobe and striatal areas while IGD subjects have negative functional connectivity between the DLPFC, temporal lobe and striatal areas.

CONCLUSIONS

AD and IGD subjects may share deficits in executive function, including problems with self-control and adaptive responding. However, the negative connectivity between the DLPFC and the striatal areas in IGD subjects, different from the connectivity observed in AD subjects, may be due to the earlier prevalence age, different comorbid diseases as well as visual and auditory stimulation.

Abnormal gray matter and white matter volume in 'Internet gaming addicts'

Internet gaming addiction (IGA) is usually defined as the inability of an individual to control his/her use of the Internet with serious negative consequences. It is becoming a prevalent mental health concern around the world. To understand whether Internet gaming addiction contributes to cerebral structural changes, the present study examined the brain gray matter density and white matter density changes in participants suffering IGA using voxel-based morphometric analysis. Compared with the healthy controls (N=36, 22.2 ± 3.13 years), IGA participants (N=35, 22.28 ± 2.54 years) showed significant lower gray matter density in the bilateral inferior frontal gyrus, left cingulate gyrus, insula, right precuneus, and right hippocampus (all p<0.05). IGA participants also showed significant lower white matter density in the inferior frontal gyrus, insula, amygdala, and anterior cingulate than healthy controls (all p<0.05). Previous studies suggest that these brain regions are involved in decision-making, behavioral inhibition and emotional regulation. Current findings might provide insight in understanding the biological underpinnings of IGA.

Gambling disorder and other behavioral addictions: recognition and treatment

Addiction professionals and the public are recognizing that certain nonsubstance behaviors--such as gambling, Internet use, video-game playing, sex, eating, and shopping--bear resemblance to alcohol and drug dependence. Growing evidence suggests that these behaviors warrant consideration as nonsubstance or "behavioral" addictions and has led to the newly introduced diagnostic category "Substance-Related and Addictive Disorders" in DSM-5. At present, only gambling disorder has been placed in this category, with insufficient data for other proposed behavioral addictions to justify their inclusion. This review summarizes recent advances in our understanding of behavioral addictions, describes treatment considerations, and addresses future directions. Current evidence points to overlaps between behavioral and substance-related addictions in phenomenology, epidemiology, comorbidity, neurobiological mechanisms, genetic contributions, responses to treatments, and prevention efforts. Differences also exist. Recognizing behavioral addictions and developing appropriate diagnostic criteria are important in order to increase awareness of these disorders and to further prevention and treatment strategies.

Licit and illicit drug use in cluster headache

Cluster headache patients seem to use more licit and illicit substances than the general population. The epidemiologic data supporting this is growing. We included the licit drugs in this review because their use seems to be driven by the same addiction mechanisms leading to illicit drug abuse. Some drugs may be used in an attempt to treat cluster headache, especially cocaine and hallucinogens. Drug exposure may also play a role in CH pathophysiology, as suggested by interesting data on tobacco use and second-hand smoke exposure. A common factor may contribute both to CH and drug use predisposition. Genetic factors may be at play, and the dopaminergic and orexinergic pathways could be targeted for future studies.

Unraveling exercise addiction: the role of narcissism and self-esteem

The aim of this study was to assess the risk of exercise addiction (EA) in fitness clubs and to identify possible factors in the development of the disorder. The Exercise Addiction Inventory (EAI), the Narcissistic Personality Inventory (NPI), and the Coopersmith Self-Esteem Inventory (SEI) were administered to a sample of 150 consecutive gym attenders recruited in fitness centers. Based on EAI total score, high EA risk group (HEA n = 51) and a low EA risk group (LEA n = 69) were identified. HEA reported significantly higher total score (mean = 20.2 versus 14.6) on the NPI scale and lower total score (mean = 32.2 versus 36.4) on the SEI scale than LEA. A stepwise regression analysis indicated that only narcissism and self-esteem total scores (F = 5.66; df = 2; P = 0.006) were good predictors of days per week exercise. The present study confirms the direct and combined role of both labile self-esteem and high narcissism in the development of exercise addiction as predictive factors towards the risk of addiction. Multidisciplinary trained health care providers (physiatrists, psychologists, and psychiatrists) should carefully identify potential overexercise conditions in order to prevent the potential risk of exercise addiction.

Sex differences in addictive disorders

Gender-dependent differences in the rate of initiation and frequency of misuse of addicting drugs have been widely described. Yet, men and women also differ in their propensity to become addicted to other rewarding stimuli (e.g., sex, food) or activities (e.g., gambling, exercising). The goal of the present review is to summarize current evidence for gender differences not only in drug addiction, but also in other forms of addictive behaviours. Thus, we first reviewed studies showing gender-dependent differences in drug addiction, food addiction, compulsive sexual activity, pathological gambling, Internet addiction and physical exercise addiction. Potential risk factors and underlying brain mechanisms are also examined, with particular emphasis given to the role of sex hormones in modulating addictive behaviours. Investigations on factors allowing the pursuit of non-drug rewards to become pathological in men and women are crucial for designing gender-appropriate treatments of both substance and non-substance addictions.

The neural bases of cognitive processes in gambling disorder

Functional imaging is offering powerful new tools to investigate the neurobiology of cognitive functioning in people with and without psychiatric conditions like gambling disorder. Based on similarities between gambling and substance-use disorders in neurocognitive and other domains, gambling disorder has recently been classified in the Diagnostic and Statistical Manual of Mental Disorders (5th edn) (DSM-5) as a behavioral addiction. Despite the advances in understanding, there exist multiple unanswered questions about the pathophysiology underlying gambling disorder and the promise for translating the neurobiological understanding into treatment advances remains largely unrealized. Here we review the neurocognitive underpinnings of gambling disorder with a view to improving prevention, treatment, and policy efforts.

New developments in human neurocognition: clinical, genetic, and brain imaging correlates of impulsivity and compulsivity

Impulsivity and compulsivity represent useful conceptualizations that involve dissociable cognitive functions, which are mediated by neuroanatomically and neurochemically distinct components of cortico-subcortical circuitry. The constructs were historically viewed as diametrically opposed, with impulsivity being associated with risk-seeking and compulsivity with harm-avoidance. However, they are increasingly recognized to be linked by shared neuropsychological mechanisms involving dysfunctional inhibition of thoughts and behaviors. In this article, we selectively review new developments in the investigation of the neurocognition of impulsivity and compulsivity in humans, in order to advance our understanding of the pathophysiology of impulsive, compulsive, and addictive disorders and indicate new directions for research.

Neurobiology of gambling behaviors

For many, gambling is a recreational activity that is performed periodically without ill effects, but for some, gambling may interfere with life functioning. A diagnostic entity, pathological gambling (PG), is currently used to define a condition marked by excessive and problematic gambling. In this review, the current status of understanding of the neurobiologies of gambling and PG is described. Multiple neurotransmitter systems (norepinephrine, serotonin, dopamine, opioid and glutamate) and brain regions (ventral striatum, ventromedial prefrontal cortex, insula, among others) have been implicated in gambling and PG. Considerations for future directions in gambling research, with a view towards translating neurobiological advances into more effective prevention and treatment strategies, are discussed.