The brain activations for both cue-induced gaming urge and smoking craving among subjects comorbid with Internet gaming addiction and nicotine dependence

Cue-induced craving for Internet among Internet addicts

Intense craving is a core feature of addictive disorder, and cue-induced craving is believed to be a key factor in the maintenance and relapse of addictive behaviors. With the rapid development of the Internet, Internet addiction has become a widespread behavioral problem accompanied by many negative effects. This study used the cue-reactivity paradigm to examine cue-induced craving for the Internet among Internet addicts and non-addicts. Participants were exposed to Internet-related words, and asked to report their craving for the Internet. Results indicated that Internet-related words aroused cue-induced craving for the Internet among both Internet addicts and non-addicts; however, the craving was more intense among Internet addicts. These results suggest that craving may not be a unipolar, all or none state found only in addicts, but may also be present among non-addicts. They indicate that Internet-related words may be able to induce craving for the Internet, and that Internet addiction and other addictions may share similar underlying mechanisms. This finding has important implications for designing interventions for Internet addiction.

Prevalence, correlates, psychiatric comorbidities, and suicidality in a community population with problematic Internet use

We examined the prevalence, correlates, and psychiatric comorbidities of community-dwelling subjects with problematic Internet use (PIU). In an epidemiological survey of mental disorders among Korean adults conducted in 2006, 6510 subjects (aged 18-64 years) completed the Korean version of the Composite International Diagnostic Interview for DSM-IV psychiatric disorders; Diagnostic Interview Schedule exploring pathological gambling; Adult ADHD Self-Report Scale-Version 1.1 Screener; questionnaire for sleep disturbances; and questionnaire for suicidal ideations, plans, and attempts. Young's Internet Addiction Test was administered to 3212 individuals who had used the Internet within one month before the interviews in order to identify problematic Internet users (cutoff >39). The prevalence of PIU was 9.3% in the general population of South Korea. Being male, younger, never married, or unemployed were all associated with increased risks of PIU. Significant positive associations were observed between PIU and nicotine use disorders, alcohol use disorders, mood disorders, anxiety disorders, somatoform disorders, pathological gambling, adult type ADHD symptoms, sleep disturbances, suicide ideas and suicide plans compare to subjects without PIU, after controlling for socio-demographic variables. These findings suggest that careful evaluation and management of such psychiatric disorders is needed for individuals with PIU.

Effects of craving behavioral intervention on neural substrates of cue-induced craving in Internet gaming disorder

Internet gaming disorder (IGD) is characterized by high levels of craving for online gaming and related cues. Since addiction-related cues can evoke increased activation in brain areas involved in motivational and reward processing and may engender gaming behaviors or trigger relapse, ameliorating cue-induced craving may be a promising target for interventions for IGD. This study compared neural activation between 40 IGD and 19 healthy control (HC) subjects during an Internet-gaming cue-reactivity task and found that IGD subjects showed stronger activation in multiple brain areas, including the dorsal striatum, brainstem, substantia nigra, and anterior cingulate cortex, but lower activation in the posterior insula. Furthermore, twenty-three IGD subjects (CBI + group) participated in a craving behavioral intervention (CBI) group therapy, whereas the remaining 17 IGD subjects (CBI − group) did not receive any intervention, and all IGD subjects were scanned during similar time intervals. The CBI + group showed decreased IGD severity and cue-induced craving, enhanced activation in the anterior insula and decreased insular connectivity with the lingual gyrus and precuneus after receiving CBI. These findings suggest that CBI is effective in reducing craving and severity in IGD, and it may exert its effects by altering insula activation and its connectivity with regions involved in visual processing and attention bias.

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IGD subjects showed altered cue-induced neural activation in reward-related areas.

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IGD subjects alleviated IGD symptoms after CBI.

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IGD subjects showed higher insular activation after CBI.

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IGD subjects showed lower insula-lingual gyrus/precuneus connectivity after CBI.

Largely overlapping neuronal substrates of reactivity to drug, gambling, food and sexual cues: A comprehensive meta-analysis

Cue reactivity to natural and social rewards is essential for motivational behavior. However, cue reactivity to drug rewards can also elicit craving in addicted subjects. The degree to which drug and natural rewards share neural substrates is not known. The objective of this study is to conduct a comprehensive meta-analysis of neuroimaging studies on drug, gambling and natural stimuli (food and sex) to identify the common and distinct neural substrates of cue reactivity to drug and natural rewards. Neural cue reactivity studies were selected for the meta-analysis by means of activation likelihood estimations, followed by sensitivity and clustering analyses of averaged neuronal response patterns. Data from 176 studies (5573 individuals) suggests largely overlapping neural response patterns towards all tested reward modalities. Common cue reactivity to natural and drug rewards was expressed by bilateral neural responses within anterior cingulate gyrus, insula, caudate head, inferior frontal gyrus, middle frontal gyrus and cerebellum. However, drug cues also generated distinct activation patterns in medial frontal gyrus, middle temporal gyrus, posterior cingulate gyrus, caudate body and putamen. Natural (sexual) reward cues induced unique activation of the pulvinar in thalamus. Neural substrates of cue reactivity to alcohol, drugs of abuse, food, sex and gambling are largely overlapping and comprise a network that processes reward, emotional responses and habit formation. This suggests that cue-mediated craving involves mechanisms that are not exclusive for addictive disorders but rather resemble the intersection of information pathways for processing reward, emotional responses, non-declarative memory and obsessive-compulsive behavior.

Altered brain functional networks in people with Internet gaming disorder: Evidence from resting-state fMRI

Although numerous neuroimaging studies have detected structural and functional abnormality in specific brain regions and connections in subjects with Internet gaming disorder (IGD), the topological organization of the whole-brain network in IGD remain unclear. In this study, we applied graph theoretical analysis to explore the intrinsic topological properties of brain networks in Internet gaming disorder (IGD). 37 IGD subjects and 35 matched healthy control (HC) subjects underwent a resting-state functional magnetic resonance imaging scan. The functional networks were constructed by thresholding partial correlation matrices of 90 brain regions. Then we applied graph-based approaches to analysis their topological attributes, including small-worldness, nodal metrics, and efficiency. Both IGD and HC subjects show efficient and economic brain network, and small-world topology. Although there was no significant group difference in global topology metrics, the IGD subjects showed reduced regional centralities in the prefrontal cortex, left posterior cingulate cortex, right amygdala, and bilateral lingual gyrus, and increased functional connectivity in sensory-motor-related brain networks compared to the HC subjects. These results imply that people with IGD may be associated with functional network dysfunction, including impaired executive control and emotional management, but enhanced coordination among visual, sensorimotor, auditory and visuospatial systems.

Altered resting-state neural activity and changes following a craving behavioral intervention for Internet gaming disorder

Internet gaming disorder (IGD) has become a serious mental health issue worldwide. Evaluating the benefits of interventions for IGD is of great significance. Thirty-six young adults with IGD and 19 healthy comparison (HC) subjects were recruited and underwent resting-state fMRI scanning. Twenty IGD subjects participated in a group craving behavioral intervention (CBI) and were scanned before and after the intervention. The remaining 16 IGD subjects did not receive an intervention. The results showed that IGD subjects showed decreased amplitude of low fluctuation in the orbital frontal cortex and posterior cingulate cortex, and exhibited increased resting-state functional connectivity between the posterior cingulate cortex and dorsolateral prefrontal cortex, compared with HC subjects. Compared with IGD subjects who did not receive the intervention, those receiving CBI demonstrated significantly reduced resting-state functional connectivity between the: (1) orbital frontal cortex with hippocampus/parahippocampal gyrus; and, (2) posterior cingulate cortex with supplementary motor area, precentral gyrus, and postcentral gyrus. These findings suggest that IGD is associated with abnormal resting-state neural activity in reward-related, default mode and executive control networks. Thus, the CBI may exert effects by reducing interactions between regions within a reward-related network, and across the default mode and executive control networks.

Sex and Gender Differences in Central Nervous System-Related Disorders

There are important sex differences in the brain that seem to arise from biology as well as psychosocial influences. Sex differences in several aspects of human behavior and cognition have been reported. Gonadal sex steroids or genes found on sex chromosomes influence sex differences in neuroanatomy, neurochemistry and neuronal structure, and connectivity. There has been some resistance to accept that sex differences in the human brain exist and have biological relevance; however, a few years ago, it has been recommended by the USA National Institute of Mental Health to incorporate sex as a variable in experimental and clinical neurological and psychiatric studies. We here review the clinical literature on sex differences in pain and neurological and psychiatric diseases, with the aim to further stimulate interest in sexual dimorphisms in the brain and brain diseases, possibly encouraging more research in the field of the implications of sex differences for treating these conditions.

Cue-induced Behavioral and Neural Changes among Excessive Internet Gamers and Possible Application of Cue Exposure Therapy to Internet Gaming Disorder

Internet gaming disorder (IGD) may lead to many negative consequences in everyday life, yet there is currently no effective treatment for IGD. Cue-reactivity paradigm is commonly used to evaluate craving for substance, food, and gambling; cue exposure therapy (CET) is applied to treating substance use disorders (SUDs) and some other psychological disorders such as pathological gambling (PG). However, no study has explored CET's application to the treatment of IGD except two articles having implied that cues' exposure may have therapeutic effect on IGD. This paper reviews studies on cue-induced behavioral and neural changes in excessive Internet gamers, indicating that behavioral and neural mechanisms of IGD mostly overlap with those of SUD. The CET's effects in the treatment of SUDs and PG are also reviewed. We finally propose an optimized CET paradigm, which future studies should consider and investigate as a probable treatment of IGD.

Problematic Internet Users Show Impaired Inhibitory Control and Risk Taking with Losses: Evidence from Stop Signal and Mixed Gambles Tasks

According to the balance model of self-regulation, dysfunction of the inhibitory control and reward processing might be a behavioral marker for addiction and problematic behaviors. Although several studies have separately examined the inhibitory control or reward processing of individuals exhibiting problematic Internet use (PIU), no study has explored these two functions simultaneously to examine the potential imbalance of these functions. This study aimed to investigate whether the self-regulatory failure of PIU individuals results from deficits in both inhibitory control [indexed with the stop signal reaction time (SSRT) in a stop signal task] and risk taking with losses (measured as the acceptance rates of risky gables or the ratio of win/loss in a mixed gambles task). The results revealed that PIU individuals, compared with controls, showed decreased SSRT and increased error rates as well as reduced risk taking with losses. Correlational analyses revealed a significant positive relationship between the SSRT and risk taking with losses. These findings suggest that both the inhibitory control and reward functions are impaired in PIU individuals and reveal an association between these two systems. These results strengthen the balance model of self-regulation theory's argument that deficits in inhibitory control and risk taking with losses may assist in identifying risk markers for early diagnosis, progression, and prediction of PIU.

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.

Internet Gaming Disorder in the DSM-5

The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes in its research appendix a potential new diagnosis-Internet gaming disorder. This article outlines the debate surrounding non-substance addictions and the rationale for including this condition in the "Conditions for Further Study" chapter in DSM-5 Section III. It also describes the diagnostic criteria that DSM-5 recommends and methods to assess Internet gaming disorder. The paper details international research related to prevalence rates, demographic, psychiatric, and neurobiological risk factors, the natural course of the condition, and promising treatment approaches. The paper concludes by describing important issues for research to address prior to official recognition of this condition as a mental disorder.

Smoking in Video Games: A Systematic Review

INTRODUCTION

Video games are played by a majority of adolescents, yet little is known about whether and how video games are associated with smoking behavior and attitudes. This systematic review examines research on the relationship between video games and smoking.

METHODS

We searched MEDLINE, psycINFO, and Web of Science through August 20, 2014. Twenty-four studies met inclusion criteria. Studies were synthesized qualitatively in four domains: the prevalence and incidence of smoking imagery in video games (n = 6), video game playing and smoking behavior (n = 11), video game addiction and tobacco addiction (n = 5) and genre-specific game playing and smoking behavior (n = 3).

RESULTS

Tobacco content was present in a subset of video games. The literature is inconclusive as to whether exposure to video games as a single construct is associated with smoking behavior. Four of five studies found an association between video game addiction and smoking. For genre-specific game playing, studies suggest that the type of game played affected association with smoking behavior.

CONCLUSIONS

Research on how playing video games influences adolescents' perceptions of smoking and smoking behaviors is still in its nascence. Further research is needed to understand how adolescents respond to viewing and manipulating tobacco imagery, and whether engaging in game smoking translates into changes in real-world attitudes or behavior. Smoking imagery in video games may contribute to normalizing adolescent smoking.

IMPLICATIONS

A large body of research has shown that smoking imagery in a variety of media types contributes to adolescent smoking uptake and the normalization of smoking behavior, and almost 90% of adolescents play video games, yet there has never been a published systematic review of the literature on this important topic. This is the first systematic review to examine the research on tobacco and video games.We found that tobacco imagery is indeed present in video games, the relationship between video game playing and smoking remains unclear, there appears to be a correlation between problem gaming and smoking and the genre of games may play a role in adolescent smoking behavior.

Epidemiology of internet behaviors and addiction among adolescents in six Asian countries

Internet addiction has become a serious behavioral health problem in Asia. However, there are no up-to-date country comparisons. The Asian Adolescent Risk Behavior Survey (AARBS) screens and compares the prevalence of Internet behaviors and addiction in adolescents in six Asian countries. A total of 5,366 adolescents aged 12-18 years were recruited from six Asian countries: China, Hong Kong, Japan, South Korea, Malaysia, and the Philippines. Participants completed a structured questionnaire on their Internet use in the 2012-2013 school year. Internet addiction was assessed using the Internet Addiction Test (IAT) and the Revised Chen Internet Addiction Scale (CIAS-R). The variations in Internet behaviors and addiction across countries were examined. The overall prevalence of smartphone ownership is 62%, ranging from 41% in China to 84% in South Korea. Moreover, participation in online gaming ranges from 11% in China to 39% in Japan. Hong Kong has the highest number of adolescents reporting daily or above Internet use (68%). Internet addiction is highest in the Philippines, according to both the IAT (5%) and the CIAS-R (21%). Internet addictive behavior is common among adolescents in Asian countries. Problematic Internet use is prevalent and characterized by risky cyberbehaviors.

Molecular and functional imaging of internet addiction

Maladaptive use of the Internet results in Internet addiction (IA), which is associated with various negative consequences. Molecular and functional imaging techniques have been increasingly used for analysis of neurobiological changes and neurochemical correlates of IA. This review summarizes molecular and functional imaging findings on neurobiological mechanisms of IA, focusing on magnetic resonance imaging (MRI) and nuclear imaging modalities including positron emission tomography (PET) and single photon emission computed tomography (SPECT). MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects. Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems. Abnormal dopamine regulation of the prefrontal cortex (PFC) could underlie the enhanced motivational value and uncontrolled behavior over Internet overuse in addicted subjects. Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

The alteration of gray matter volume and cognitive control in adolescents with internet gaming disorder

Objective: Internet gaming disorder (IGD) has been investigated by many behavioral and neuroimaging studies, for it has became one of the main behavior disorders among adolescents. However, few studies focused on the relationship between alteration of gray matter volume (GMV) and cognitive control feature in IGD adolescents.

Methods: Twenty-eight participants with IAD and twenty-eight healthy age and gender matched controls participated in the study. Brain morphology of adolescents with IGD and healthy controls was investigated using an optimized voxel-based morphometry (VBM) technique. Cognitive control performances were measured by Stroop task, and correlation analysis was performed between brain structural change and behavioral performance in IGD group.

Results: The results showed that GMV of the bilateral anterior cingulate cortex (ACC), precuneus, supplementary motor area (SMA), superior parietal cortex, left dorsal lateral prefrontal cortex (DLPFC), left insula, and bilateral cerebellum decreased in the IGD participants compared with healthy controls. Moreover, GMV of the ACC was negatively correlated with the incongruent response errors of Stroop task in IGD group.

Conclusion: Our results suggest that the alteration of GMV is associated with the performance change of cognitive control in adolescents with IGD, which indicating substantial brain image effects induced by IGD.

The impact of Internet-based specific activities on the perceptions of Internet addiction, quality of life, and excessive usage: A cross-sectional study

Introduction

Recent research has examined the context in which preference for specific online activities arises, leading researchers to suggest that excessive Internet users are engaged in specific activities rather than ‘generalized’ Internet use. The present study aimed to partially replicate and expand these findings by addressing four research questions regarding (i) participants' preferred online activities, (i) possible expected changes in online behavior in light of hypothetical scenarios, (iii) perceived quality of life when access to Internet was not possible, and (iv) how participants with self-diagnosed Internet addiction relate to intensity and frequency of Internet use.

Methods

A cross-sectional design was adopted using convenience and snowball sampling to recruit participants. A total of 1057 Internet users with ages ranging from 16 to 70 years (M_age = 30 years, SD = 10.84) were recruited online via several English-speaking online forums.

Results

Most participants indicated that their preferred activities were (i) accessing general information and news, (ii) social networking, and (iii) using e-mail and/or online chatting. Participants also reported that there would be a significant decrease of their Internet use if access to their preferred activities was restricted. The study also found that 51% of the total sample perceived themselves as being addicted to the Internet, while 14.1% reported that without the Internet their life would be improved.

Conclusions

The context in which the Internet is used appears to determine the intensity and the lengths that individuals will go to use this tool. The implications of these findings are further discussed.

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Preferred non-work online activities were of informational and social nature.

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Online behaviors may change by manipulating the availability of online activities.

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Perceived quality of life can be affected in the absence of Internet access.

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Perception of Internet addiction may be a useful indicator of possible addiction.

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Specific online activities are associated with perceived Internet addiction.

Imbalanced functional link between executive control network and reward network explain the online-game seeking behaviors in Internet gaming disorder

Literatures have shown that Internet gaming disorder (IGD) subjects show impaired executive control and enhanced reward sensitivities than healthy controls. However, how these two networks jointly affect the valuation process and drive IGD subjects' online-game-seeking behaviors remains unknown. Thirty-five IGD and 36 healthy controls underwent a resting-states scan in the MRI scanner. Functional connectivity (FC) was examined within control and reward network seeds regions, respectively. Nucleus accumbens (NAcc) was selected as the node to find the interactions between these two networks. IGD subjects show decreased FC in the executive control network and increased FC in the reward network when comparing with the healthy controls. When examining the correlations between the NAcc and the executive control/reward networks, the link between the NAcc - executive control network is negatively related with the link between NAcc - reward network. The changes (decrease/increase) in IGD subjects' brain synchrony in control/reward networks suggest the inefficient/overly processing within neural circuitry underlying these processes. The inverse proportion between control network and reward network in IGD suggest that impairments in executive control lead to inefficient inhibition of enhanced cravings to excessive online game playing. This might shed light on the mechanistic understanding of IGD.

Decreased functional connectivity in an executive control network is related to impaired executive function in Internet gaming disorder

BACKGROUND

Resting brain spontaneous neural activities across cortical regions have been correlated with specific functional properties in psychiatric groups. Individuals with Internet gaming disorder (IGD) demonstrate impaired executive control. Thus, it is important to examine executive control networks (ECNs) during resting states and their relationships to executive control during task performance.

METHODS

Thirty-five IGD and 36 healthy control participants underwent a resting-state fMRI scan and performed a Stroop task inside and outside of the MRI scanner. Correlations between Stroop effect and functional connectivity among ECN regions of interest (ROIs) were calculated within and between groups.

RESULTS

IGD subjects show lower functional connectivity in ECNs than do HC participants during resting state; functional-connectivity measures in ECNs were negatively correlated with Stroop effect and positively correlated with brain activations in executive-control regions across groups. Within groups, negative trends were found between Stroop effect and functional connectivity in ECNs in IGD and HC groups, separately; positive trends were found between functional connectivity in ECNs and brain activations in Stroop task in IGD and HC groups, separately.

CONCLUSIONS

Higher functional connectivity in ECNs may underlie better executive control and may provide resilience with respect to IGD. Lower functional connectivity in ECNs may represent an important feature in understanding and treating IGD.

Impaired risk evaluation in people with Internet gaming disorder: fMRI evidence from a probability discounting task

This study examined how Internet gaming disorder (IGD) subjects modulating reward and risk at a neural level under a probability-discounting task with functional magnetic resonance imaging (fMRI). Behavioral and imaging data were collected from 19 IGD subjects (22.2 ± 3.08 years) and 21 healthy controls (HC, 22.8 ± 3.5 years). Behavior results showed that IGD subjects prefer the probabilistic options to fixed ones and were associated with shorter reaction time, when comparing to HC. The fMRI results revealed that IGD subjects show decreased activation in the inferior frontal gyrus and the precentral gyrus when choosing the probabilistic options than HC. Correlations were also calculated between behavioral performances and brain activities in relevant brain regions. Both of the behavioral performance and fMRI results indicate that people with IGD show impaired risk evaluation, which might be the reason why IGD subjects continue playing online games despite the risks of widely known negative consequence.

New Concepts, Old Known Issues

Background: Following the growing concern about ‘gaming addiction', the American Psychiatric Association (APA) and numerous scholars have suggested the need for unification and consensus for the assessment of gaming addiction, which is now possible given the recent formal recognition of ‘Internet Gaming Disorder' (IGD) by the APA since its inclusion in the DSM-5. Aims: In light of this, the aim of this chapter is to present the main findings concerning the development of the Internet Gaming Disorder Test (IGD-20 Test) and the Internet Gaming Disorder Scale – Short-Form (IGDS9-SF), two newly developed psychometric tools aimed to measure the extent of gaming disorder in online and/or offline players. Conclusions: The present findings support the viability of the two newly developed measures as adequate standardized psychometrically robust tools for assessing internet gaming disorder. Consequently, the new instruments represent the first step towards unification and consensus in the field of gaming studies.

Examination of Neural Systems Sub-Serving Facebook “Addiction”

Because addictive behaviors typically result from violated homeostasis of the impulsive (amygdala-striatal) and inhibitory (prefrontal cortex) brain systems, this study examined whether these systems sub-serve a specific case of technology-related addiction, namely Facebook “addiction.” Using a go/no-go paradigm in functional MRI settings, the study examined how these brain systems in 20 Facebook users ( M age = 20.3 yr., SD = 1.3, range = 18–23) who completed a Facebook addiction questionnaire, responded to Facebook and less potent (traffic sign) stimuli. The findings indicated that at least at the examined levels of addiction-like symptoms, technology-related “addictions” share some neural features with substance and gambling addictions, but more importantly they also differ from such addictions in their brain etiology and possibly pathogenesis, as related to abnormal functioning of the inhibitory-control brain system.

Different resting-state functional connectivity alterations in smokers and nonsmokers with Internet gaming addiction

This study investigated changes in resting-state functional connectivity (rsFC) of posterior cingulate cortex (PCC) in smokers and nonsmokers with Internet gaming addiction (IGA). Twenty-nine smokers with IGA, 22 nonsmokers with IGA, and 30 healthy controls (HC group) underwent a resting-state fMRI scan. PCC connectivity was determined in all subjects by investigating synchronized low-frequency fMRI signal fluctuations using a temporal correlation method. Compared with the nonsmokers with IGA, the smokers with IGA exhibited decreased rsFC with PCC in the right rectus gyrus. Left middle frontal gyrus exhibited increased rsFC. The PCC connectivity with the right rectus gyrus was found to be negatively correlated with the CIAS scores in the smokers with IGA before correction. Our results suggested that smokers with IGA had functional changes in brain areas related to motivation and executive function compared with the nonsmokers with IGA.

Reward processing in obesity, substance addiction and non-substance addiction

Similarities and differences between obesity and addiction are a prominent topic of ongoing research. We conducted an activation likelihood estimation meta-analysis on 87 studies in order to map the functional magnetic resonance imaging (fMRI) response to reward in participants with obesity, substance addiction and non-substance (or behavioural) addiction, and to identify commonalities and differences between them. Our study confirms the existence of alterations during reward processing in obesity, non-substance addiction and substance addiction. Specifically, participants with obesity or with addictions differed from controls in several brain regions including prefrontal areas, subcortical structures and sensory areas. Additionally, participants with obesity and substance addictions exhibited similar blood-oxygen-level-dependent fMRI hyperactivity in the amygdala and striatum when processing either general rewarding stimuli or the problematic stimuli (food and drug-related stimuli, respectively). We propose that these similarities may be associated with an enhanced focus on reward--especially with regard to food or drug-related stimuli--in obesity and substance addiction. Ultimately, this enhancement of reward processes may facilitate the presence of compulsive-like behaviour in some individuals or under some specific circumstances. We hope that increasing knowledge about the neurobehavioural correlates of obesity and addictions will lead to practical strategies that target the high prevalence of these central public health challenges.

Cue-induced craving in pathological buying: empirical evidence and clinical implications

OBJECTIVE

Pathological buying is associated with marked distress and impaired functioning in important life domains. It is currently under debate whether pathological buying can be considered a behavioral addiction. In analogy to results reported in addicted individuals, craving reactions elicited by addiction-related cues might be an underlying mechanism for the etiology and pathogenesis of pathological buying.

METHODS

In the present study, 30 pathological buyers and 30 matched control participants were examined with a cue-reactivity paradigm consisting of shopping and control cues. Skin conductance responses, as well as subjective ratings for arousal, valence, and urge to buy, were assessed. Subjective craving reactions were measured before and after the cue-reactivity paradigm.

RESULTS

On a physiological level, skin conductance responses toward shopping cues were higher in pathological buyers (mean [M; standard deviation {SD}] = 0.26 [0.13]) compared with control participants (M [SD] = 0.19 [0.09]; t(58) = 2.29, p = .025, d = 0.60). On a behavioral level, the individuals with pathological buying rated the shopping cues as more arousing and more positive, and reported a greater urge to buy compared with control participants and with control cues. An increase in subjective craving after completing the cue-reactivity paradigm was observed only in the pathological buyers (Mpre [SD] = 1.95 [1.47], Mpost [SD] = 2.87 [1.79]; t(29) = 5.07, p < .001, d = 0.97).

CONCLUSIONS

Cue-reactivity and craving might be potential correlates for the development and maintenance of pathological buying. The results demonstrate similarities between pathological buying and substance or behavioral addictions and provide implications for clinical treatment.

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 association between cue-reactivity in the precuneus and level of dependence on nicotine and alcohol

BACKGROUND

Given numerous reports implicating involvement of the precuneus in cue-reactivity paradigms, the goal of this investigation was to examine the relationship between activation of the precuneus in response to drug cues and measures of subjective craving and severity of dependence in volunteers who were comorbid for alcohol and nicotine abuse.

METHODS

Forty research participants, who all reported heavy drinking and daily smoking, were recruited (15 women; 70% Caucasian; mean age=31.2 years) for a functional magnetic resonance imaging (fMRI) session involving a cigarette video-cues task and an alcohol taste-cues task. Mean precuneus activation from both tasks during cue presentation was subjected to bivariate correlation analyses with indices of dependence severity and subjective craving.

RESULTS

Precuneus activation in the contrast of Cigarette Cues vs. Control Cues was positively correlated with scores on the Fagerström Test of Nicotine Dependence (r=0.389, p=0.016), and activation in the Alcohol Cues vs. Control Cues contrast was positively correlated with Alcohol Dependence Scale scores (r=0.338, p=0.038). No correlations with subjective craving were observed (ps>0.05).

CONCLUSIONS

These findings indicate that the precuneus is involved in cue reactivity for both cigarettes and alcohol, and that this involvement is moderated by severity of drug dependence. The precuneus may be a cortical locus for neuroplastic changes related to drug dependence.

Treatment outcomes in patients with internet addiction: a clinical pilot study on the effects of a cognitive-behavioral therapy program

Internet addiction is regarded as a growing health concern in many parts of the world with prevalence rates of 1-2% in Europe and up to 7% in some Asian countries. Clinical research has demonstrated that Internet addiction is accompanied with loss of interests, decreased psychosocial functioning, social retreat, and heightened psychosocial distress. Specialized treatment programs are needed to face this problem that has recently been added to the appendix of the DSM-5. While there are numerous studies assessing clinical characteristics of patients with Internet addiction, the knowledge about the effectiveness of treatment programs is limited. Although a recent meta-analysis indicates that those programs show effects, more clinical studies are needed here. To add knowledge, we conducted a pilot study on the effects of a standardized cognitive-behavioral therapy program for IA. 42 male adults meeting criteria for Internet addiction were enrolled. Their IA-status, psychopathological symptoms, and perceived self-efficacy expectancy were assessed before and after the treatment. The results show that 70.3% of the patients finished the therapy regularly. After treatment symptoms of IA had decreased significantly. Psychopathological symptoms were reduced as well as associated psychosocial problems. The results of this pilot study emphasize findings from the only meta-analysis conducted so far.

Evaluation of the diagnostic criteria of Internet gaming disorder in the DSM-5 among young adults in Taiwan

The DSM-5 proposed the diagnostic criteria of Internet gaming disorder (IGD) and suggested that more evidence is necessary before it is included as a standard disorder in the DSM system. The aims of this study were to: 1) evaluate the diagnostic validity of individual criteria of IGD in the DSM-5 and the criteria of craving and irritability; 2) determine the optimal cut-off point for the IGD criteria in the DSM-5. We recruited 75 subjects with IGD, 75 without IGD, and 75 in remission from IGD based on the Diagnostic Criteria of Internet Addiction for College Students (DC-IA-C). All participants underwent a diagnostic interview based on the diagnostic criteria of IGD in the DSM-5 and completed the CIAS and QGU-B. Except for the "deceiving" and "escape" criteria, all criteria of IGD had diagnostic accuracy ranging from 77.3% to 94.7% to differentiate university students with IGD from remitted students. The criterion of craving had diagnostic accuracy of 88% and the criteria of irritability had an accuracy of 68.7%. Fulfilling 5 or more criteria of IGD in the DSM-5 was the best cut-off point to differentiate young adults with IGD from healthy or remitted users.

Prefrontal control and internet addiction: a theoretical model and review of neuropsychological and neuroimaging findings

Most people use the Internet as a functional tool to perform their personal goals in everyday-life such as making airline or hotel reservations. However, some individuals suffer from a loss of control over their Internet use resulting in personal distress, symptoms of psychological dependence, and diverse negative consequences. This phenomenon is often referred to as Internet addiction. Only Internet Gaming Disorder has been included in the appendix of the DSM-5, but it has already been argued that Internet addiction could also comprise problematic use of other applications with cybersex, online relations, shopping, and information search being Internet facets at risk for developing an addictive behavior. Neuropsychological investigations have pointed out that certain prefrontal functions in particular executive control functions are related to symptoms of Internet addiction, which is in line with recent theoretical models on the development and maintenance of the addictive use of the Internet. Control processes are particularly reduced when individuals with Internet addiction are confronted with Internet-related cues representing their first choice use. For example, processing Internet-related cues interferes with working memory performance and decision making. Consistent with this, results from functional neuroimaging and other neuropsychological studies demonstrate that cue-reactivity, craving, and decision making are important concepts for understanding Internet addiction. The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. The neuropsychological and neuroimaging results have important clinical impact, as one therapy goal should enhance control over the Internet use by modifying specific cognitions and Internet use expectancies.

Cognitive flexibility in internet addicts: fMRI evidence from difficult-to-easy and easy-to-difficult switching situations

Internet addiction disorder (IAD) has raised widespread public health concerns. In this study, we explored the cognitive flexibility in IAD subjects using a color-word Stroop task. Behavioral and imaging data were collected from 15 IAD subjects (21.2±3.2years) and 15 healthy controls (HC, 22.1±3.6years). Group comparisons found that IAD subjects show higher superior temporal gyrus activations than healthy controls in switching (easy to difficult; difficult to easy) than in repeating trials. In addition, in difficult-to-easy situation, IAD subjects show higher brain activation in bilateral insula than healthy controls; in easy-to-difficult situation, IAD subjects show higher brain activation in bilateral precuneus than healthy controls. Correlations were also performed between behavioral performances and brain activities in relevant brain regions. Taken together, we concluded that IAD subjects engaged more endeavors in executive control and attention in the switching task. From another perspective, IAD subjects show impaired cognitive flexibilities.