Opioid use disorder (OUD) has become a considerable global public health challenge; however, potential medications for the management of OUD that are effective, safe, and nonaddictive are not available. Accumulating preclinical evidence indicates that antagonists of the dopamine D₃ receptor (D₃R) have effects on addiction in different animal models. We have previously reported that YQA14, a D₃R antagonist, exhibits very high affinity and selectivity for D₃Rs over D₂Rs, and is able to inhibit cocaine- or methamphetamine-induced reinforcement and reinstatement in self-administration tests. In the present study, our results illustrated that YQA14 dose-dependently reduced infusions under the fixed-ratio 2 procedure and lowered the breakpoint under the progressive-ratio procedure in heroin self-administered rats, also attenuated heroin-induced reinstatement of drug-seeking behavior. On the other hand, YQA14 not only reduced morphine-induced expression of conditioned place preference but also facilitated the extinguishing process in mice. Moreover, we elucidated that YQA14 attenuated opioid-induced reward or reinforcement mainly by inhibiting morphine-induced up-regulation of dopaminergic neuron activity in the ventral tegmental area and decreasing dopamine release in the nucleus accumbens with a fiber photometry recording system. These findings suggest that D₃R might play a very important role in opioid addiction, and YQA14 may have pharmacotherapeutic potential in attenuating opioid-induced addictive behaviors dependent on the dopamine system.
Rats ; Mice ; Animals ; Analgesics, Opioid ; Dopamine ; Heroin/pharmacology* ; Dopamine Antagonists/pharmacology* ; Receptors, Dopamine D3/metabolism* ; Morphine/pharmacology* ; Behavior, Addictive/drug therapy* ; Self Administration

With the proliferation of synthetic drugs, research on the mechanism of action of addictive drugs and treatment methods is of great significance. Among them, methamphetamine (METH) is the most representative amphetamine synthetic drug, and the treatment of METH addiction has become an urgent medical and social problem. In recent years, the therapeutic effects of Chinese herbal medicines on METH addiction have gained widespread attention because of their non-addictiveness, multiple targets, low side effects, low cost, and other characteristics. Previous studies have identified a variety of Chinese herbal medicines with effects on METH addiction. Based on the research on METH in recent years, this article summarizes the mechanism of action of METH as the starting point and briefly reviews the Chinese herbal medicine-based treatment of METH.
Humans ; Methamphetamine/adverse effects* ; Drugs, Chinese Herbal/therapeutic use* ; Amphetamine/therapeutic use* ; Behavior, Addictive/drug therapy* ; Amphetamine-Related Disorders/drug therapy*

PURPOSE: Smartphone overdependence in young adults is a growing issue, that requires a vigorous approach to manage its associated problems in the affected ones. This study was designed to suggest a detailed direction to help university students with smartphone overdependence, who would be internally motivated through satisfying their basic needs based on the self-determination theory (SDT). METHODS: The data were collected via face-to-face interviews with twenty program providers, who have managed the program for preventing and treating the smartphone overdependence. All interviews were audio-recorded and transcribed. The data were analyzed using directed qualitative content analysis. RESULTS: One core category emerged from the findings: ‘Empowering motivation of autonomous actor of change associated with environmental context,’ which three generic categories and seven subcategories supported. Apart from the three basic needs in the SDT, autonomy, relatedness, and competence, no additional concepts were mentioned, but the participants complained about the practical difficulties of running programs with non-motivated students. CONCLUSION: Our study findings emphasize that research and clinical practice for young people with smartphone overdependence should focus more on developing detailed program contents synchronized with theoretical and conceptual guidance.
Behavior, Addictive ; Humans ; Mental Competency ; Motivation ; Qualitative Research ; Running ; Smartphone ; Young Adult

BACKGROUND: School teachers have a possibility toward at-risk Internet addiction (IA) due to increased opportunities to use the Internet, along with the spread of the Internet in recent years. Burnout syndrome (BOS) is found to be one of the symptoms related to unhealthy mental health, especially among teachers. This study aims to research the relationship between at-risk IA and the Internet usage or BOS by conducting a nationwide cross-sectional survey and examining the factors associated with IA. METHOD: This study was a cross-sectional survey by anonymous questionnaire. This survey was a random sampling survey of junior high schools across Japan in 2016. The participants were 1696 teachers at 73 schools (response rate in teachers 51.0%). We asked participants for details of their backgrounds, Internet usage, the Internet Addiction Test (IAT) by Young, and the Japanese Burnout Scale (JBS). We divided the participants into either the at-risk IA group (IAT score ≧ 40, n = 96) or the non-IA group (IAT score < 40, n = 1600). To compare the difference between at-risk IA and non-IA, we used nonparametric tests and t test according to variables. To analyze the relationship between the IAT score and the scores of three factors of the JBS (emotional exhaustion, depersonalization, and personal accomplishment), we used both ANOVA and ANCOVA, adjusted by relevant confounding factors. To clarify the contribution of each independent variable to IAT scores, we used multiple logistic regression analysis. RESULTS: In our study, at-risk IA was associated with using the internet many hours privately, being on the Internet both on weekdays and weekends, playing games, and surfing the Internet. In the relationship between IAT score and BOS factor score, a higher score for "depersonalization" had a positive relationship with at-risk IA, and the highest quartile for "decline of personal accomplishment" had a lower odds ratio with at-risk IA by multiple logistic regression analysis. CONCLUSION We clarified there is a significant relationship between at-risk IA and BOS among junior high school teachers in a nationwide survey. Our results suggest that finding depersonalization at the early stage may lead to the prevention of at-risk IA among teachers. Those who are at-risk of IA may feel personal accomplishment through use of the Internet.
Adult ; Analysis of Variance ; Behavior, Addictive ; psychology ; Burnout, Psychological ; psychology ; Cross-Sectional Studies ; Humans ; Internet ; Japan ; Male ; Middle Aged ; Personal Satisfaction ; Risk Factors ; School Teachers ; psychology ; Schools ; Surveys and Questionnaires

PURPOSE: The purpose of this study was to examine the association of multiple addiction risks with life satisfaction, depression, and suicidal ideation in Korean adults. METHODS: This study was descriptive correlational. Data were collected in 800 adults (405 males, 395 females) aged 20 to 69 years recruited using the proportional allocation in a city on April 2017. The structured questionnaire consisted of the Alcohol Use Disorders Identification Test, the Internet Addiction Proneness Scale for adults, the Problem Gambling Severity Index, the Drug Screening Inventory, the Korean version of the Satisfaction with the Life Scale, the Patient Health Questionnaire-9, and the Scale for Suicidal Ideation. RESULTS: Adults with multiple addiction risks had a low level of life satisfaction (p=.003) and high levels of depression and suicidal ideation (p<.001) compared to other participants. Multiple addiction risks were associated with low life satisfaction (β=.12), high depression (β=.21), and suicidal ideation (β=.20). Significant factors of life satisfaction were low suicidal ideation, a simple functioning job, high level of education, and unemployment status. CONCLUSION: Multiple addiction risks are associated with life satisfaction, depression, and suicidal ideation. The comprehensive mental health assessment for multiple addictions should precede the development of preventive multidimensional interventions.
Adult ; Behavior, Addictive ; Depression ; Drug Evaluation, Preclinical ; Education ; Gambling ; Humans ; Internet ; Male ; Mental Health ; Personal Satisfaction ; Suicidal Ideation ; Unemployment

PURPOSE: The aims of this study were to evaluate a hypothetical model explaining undergraduates' interpersonal relationship ability associated with the stress of life, self-esteem, and their communication ability and to identify the mediating effect of a smartphone addiction tendency on the identified associations. METHODS: Data were collected from 201 undergraduates using a structured questionnaire from August to September 2017. Data analyses included descriptive statistics, Pearson's correlation coefficients, and structural equation modeling with SPSS AMOS 22.0. RESULTS: The participants' interpersonal relationship ability was 65.9%, explained by the stress of life, self-esteem, communication ability, and smartphone addiction tendency. The factors of undergraduates' interpersonal relationship ability were self-esteem (β=.10, p<.01) and communication ability (β=.14, p<.001). Stress of life (β=.15, p<.01) directly affected the participants' smartphone addiction tendency, which was not associated with interpersonal relationship ability. CONCLUSION: Based on our study findings, self-esteem and communication ability should be considered for developing nursing interventions to improve interpersonal relationship ability. However, a smartphone addiction tendency may be managed for undergraduates who experience excessive stress of life rather than interpersonal relationship ability. Thus, a tailored approach targeting specific needs or competence should be developed based on our data-based framework.
Behavior, Addictive ; Communication ; Humans ; Interpersonal Relations ; Mental Competency ; Negotiating ; Nursing ; Smartphone ; Statistics as Topic ; Stress, Psychological

PURPOSE: The purpose of this study is to identify the mediating effects of self-esteem between social comparison orientation and social network service (SNS) addiction in university students. METHODS: Descriptive cross-sectional survey design was employed. The data were statistically analyzed by using the descriptive and inferential statistics. Sobel test and Bootstrap method, and Kappa squared mediation effect size measure were used to identify the mediator's significance. A convenience sample of 195 subjects was recruited from two universities in Korea. RESULTS: The mean age of the subjects was 22.58±1.81. The subjects showed relatively high levels of SNS addiction with a mean score of 14.33±4.80. The overall model significantly explained 37.0% of variances in the subjects' SNS addiction after controlling gender, age, grade, major, period of SNS using, time spent on SNS per day, and times accessed SNS per day. Of the predictors, time spent on SNS per day, social comparison orientation, and self-esteem were significantly associated with SNS addiction. Self-esteem was the mediator between social comparison orientation and SNS addiction. CONCLUSION: When developing strategies for preventing SNS addiction, interventions for reducing time spent on SNS per day, not having upward social comparison orientation, and improving the self-esteem should be considered. These findings might provide a theoretical basis for developing effective strategies for preventing SNS addiction in university students.
Behavior, Addictive ; Cross-Cultural Comparison ; Cross-Sectional Studies ; Humans ; Korea ; Methods ; Negotiating ; Self Concept

Smokers keep smoking despite knowing that tobacco claims many lives, including their own and others’. What makes it hard for them to quit smoking nonetheless? Tobacco companies insist that smokers choose to smoke, according to their right to self-determination. Moreover, they insist that with motivation and willpower to quit smoking, smokers can easily stop smoking. Against this backdrop, this paper aims to discuss the addictive disease called tobacco use disorder, with an assessment of the addictiveness of tobacco and the reasons why smoking cessation is challenging, based on neuroscientific research. Nicotine that enters the body via smoking is rapidly transmitted to the central nervous system and causes various effects, including an arousal response. The changes in the nicotine receptors in the brain due to continuous smoking lead to addiction symptoms such as tolerance, craving, and withdrawal. Compared with other addictive substances, including alcohol and opioids, tobacco is more likely to cause dependence in smokers, and smokers are less likely to recover from their dependence. Moreover, the thinning of the cerebral cortex and the decrease in cognitive functions that occur with aging accelerate with smoking. Such changes occur in the structure and functions of the brain in proportion to the amount and period of smoking. In particular, abnormalities in the neural circuits that control cognition and decision-making cause loss of the ability to exert self-control and autonomy. This initiates nicotine dependence and the continuation of addictive behaviors. Therefore, smoking is considered to be a behavior that is repeated due to dependence on an addictive substance, nicotine, instead of one’s choice by free will.
Aging ; Analgesics, Opioid ; Arousal ; Behavior, Addictive ; Brain ; Central Nervous System ; Cerebral Cortex ; Cognition ; Craving ; Jurisprudence ; Motivation ; Nicotine ; Personal Autonomy ; Self-Control ; Smoke ; Smoking Cessation ; Smoking ; Tobacco Use Disorder ; Tobacco

PURPOSE: The purposes of this study were to investigate the factor of smartphone addiction based on Agnew's general strain theory and examine the mediating effects of self efficacy and self-control in the identified model of the nursing students. METHODS: Study participants were 292 nursing students recruited from 3 universities. Self-reported data were collected in September 2015 from structured questionnaires. Data were analyzed using descriptive statistics, Pearson's correlation coefficient, exploratory factor analyses, and structural equation modeling. RESULTS: Self efficacy and self-control have a direct effect on smartphone addiction in the nursing students. The relationship between depression and smartphone addiction was fully mediated by self efficacy and self-control. However, the relationships of smartphone addiction shares with college adaptation and stress were partially mediated by depression, self efficacy, and self-control. CONCLUSION: Our study findings may be used as baseline information to develop preventive intervention programs for nursing students. Nursing educators and clinicians should encourage students' self-control, improve self efficacy when dealing with those with smartphone addiction, emphasize adaptation to college, and help manage stress and depression.
Behavior, Addictive ; Depression ; Humans ; Negotiating ; Nursing ; Self Efficacy ; Self-Control ; Smartphone ; Students, Nursing

µ-opioid receptor (MOR) is a class of opioid receptors with a high affinity for enkephalins and beta-endorphin. In hippocampus, activation of MOR is known to enhance the neuronal excitability of pyramidal neurons, which has been mainly attributed to a disinhibition of pyramidal neurons via activating Gαi subunit to suppress the presynaptic release of GABA in hippocampal interneurons. In contrast, the potential role of MOR in hippocampal astrocytes, the most abundant cell type in the brain, has remained unexplored. Here, we determine the cellular and subcellular distribution of MOR in different cell types of the hippocampus by utilizing MOR-mCherry mice and two different antibodies against MOR. Consistent with previous findings, we demonstrate that MOR expression in the CA1 pyramidal layer is co-localized with axon terminals from GABAergic inhibitory neurons but not with soma of pyramidal neurons. More importantly, we demonstrate that MOR is highly expressed in CA1 hippocampal astrocytes. The ultrastructural analysis further demonstrates that the astrocytic MOR is localized in soma and processes, but not in microdomains near synapses. Lastly, we demonstrate that astrocytes in ventral tegmental area and nucleus accumbens also express MOR. Our results provide the unprecedented evidence for the presence of MOR in astrocytes, implicating potential roles of astrocytic MOR in addictive behaviors.
Animals ; Antibodies ; Astrocytes* ; Behavior, Addictive ; beta-Endorphin ; Brain ; Carisoprodol ; Enkephalins ; gamma-Aminobutyric Acid ; Hippocampus ; Interneurons ; Mice ; Microscopy, Electron ; Neurons ; Nucleus Accumbens ; Presynaptic Terminals ; Pyramidal Cells ; Receptors, Opioid ; Synapses ; Ventral Tegmental Area