Current Pharmaceutical Design - Volume 20, Issue 25, 2014

Background and aims: The primary aim of the present review was to summarize the findings of genetic studies conducted on problem and pathological gambling. Method: Literature searches were conducted using PubMed, Medline and the HuGE Navigator databases using the keywords ‘gambling’ and ‘genetic*’. Results: The literature searches identified 21 empirical studies that had analyzed data from eight independent samples. Empirical research utilizing twin data accounted for eight of the studies, while gene association data were presented in 13 studies (including one genome wide-association study [GWAS] study). Twin studies emphasized the significant role of genetic and individual environmental factors in problem and pathological gambling. Gene association studies primarily reported the involvement of the dopaminergic and serotonergic systems. Discussion: Despite the relatively low number of genetic studies, the data clearly indicated the genetic vulnerability of problem and pathological gambling. Studies to date have mainly investigated and verified the role of factors reported to be important in other types of addiction, and it is suggested that pathological gambling should be included as a subtype of ‘Reward Deficiency Syndrome’ (RDS). It is concluded that future research should attempt to identify possible gambling specific susceptibility factors.

Given the importance and the burden of pathological gambling (PG) and its effect on gamblers and their relatives, better comprehension of the phenomena involved in its development and persistence is needed. The present paper describes the previous 5 years of studies on decision making and magnetic resonance imaging in people with PG. Twenty-six studies (456 participants with PG) were included. Perseveration in monetary tasks was associated with PG despite intact executive planning abilities. PG was linked with impairment in decision making under uncertainty. Hyperactivation of the reward pathway was repeatedly found. PG was also linked with neural hyperactivation of the reward pathway during high-risk conditions and hypoactivation in low-risk conditions. Furthermore, in PG, near misses activated the brain regions related to wins. Numerous similarities were found between PG and substance use disorders, highlighting the scientific basis of the recent reclassification of PG in the spectrum of addictive disorders.

Sexual addiction, which is also known as hypersexual disorder, has largely been ignored by psychiatrists, even though the condition causes serious psychosocial problems for many people. A lack of empirical evidence on sexual addiction is the result of the disease’s complete absence from versions of the Diagnostic and Statistical Manual of Mental Disorders. However, people who were categorized as having a compulsive, impulsive, addictive sexual disorder or a hypersexual disorder reported having obsessive thoughts and behaviors as well as sexual fantasies. Existing prevalence rates of sexual addiction-related disorders range from 3% to 6%. Sexual addiction/ hypersexual disorder is used as an umbrella construct to encompass various types of problematic behaviors, including excessive masturbation, cybersex, pornography use, sexual behavior with consenting adults, telephone sex, strip club visitation, and other behaviors. The adverse consequences of sexual addiction are similar to the consequences of other addictive disorders. Addictive, somatic and psychiatric disorders coexist with sexual addiction. In recent years, research on sexual addiction has proliferated, and screening instruments have increasingly been developed to diagnose or quantify sexual addiction disorders. In our systematic review of the existing measures, 22 questionnaires were identified. As with other behavioral addictions, the appropriate treatment of sexual addiction should combine pharmacological and psychological approaches. Psychiatric and somatic comorbidities that frequently occur with sexual addiction should be integrated into the therapeutic process. Group-based treatments should also be attempted.

Compulsive buying disorder (CBD) refers to the chronic purchasing of unneeded or unwanted items, causing significant negative consequences. There are no established criteria for CBD, and operational definitions have relied on similarities with OCD, substance use disorders, and impulse control disorders. Compulsive buying disorder is common, affecting 5.8% of the general population, according to one study. Typically, CBD has early onset, frequent comorbidities, and a chronic course. The etiology of CBD is unknown, with biological, psychological and sociocultural factors proposed as likely contributors. Treatment data are limited and suggest addressing comorbid conditions and considering cognitive behavioral therapy, financial and family counseling, selective serotonin reuptake inhibitors, and naltrexone, among other possible interventions, to target CBD. Beyond treatment, educational, legislative and family-based public policy initiatives can likely help individuals with CBD and other excessive spenders.

In the last decade, Internet usage has grown tremendously on a global scale. The increasing popularity and frequency of Internet use has led to an increasing number of reports highlighting the potential negative consequences of overuse. Over the last decade, research into Internet addiction has proliferated. This paper reviews the existing 68 epidemiological studies of Internet addiction that (i) contain quantitative empirical data, (ii) have been published after 2000, (iii) include an analysis relating to Internet addiction, (iv) include a minimum of 1000 participants, and (v) provide a full-text article published in English using the database Web of Science. Assessment tools and conceptualisations, prevalence, and associated factors in adolescents and adults are scrutinised. The results reveal the following. First, no gold standard of Internet addiction classification exists as 21 different assessment instruments have been identified. They adopt official criteria for substance use disorders or pathological gambling, no or few criteria relevant for an addiction diagnosis, time spent online, or resulting problems. Second, reported prevalence rates differ as a consequence of different assessment tools and cut-offs, ranging from 0.8% in Italy to 26.7% in Hong Kong. Third, Internet addiction is associated with a number of sociodemographic, Internet use, and psychosocial factors, as well as comorbid symptoms and disorder in adolescents and adults. The results indicate that a number of core symptoms (i.e., compulsive use, negative outcomes and salience) appear relevant for diagnosis, which assimilates Internet addiction and other addictive disorders and also differentiates them, implying a conceptualisation as syndrome with similar etiology and components, but different expressions of addictions. Limitations include the exclusion of studies with smaller sample sizes and studies focusing on specific online behaviours. Conclusively, there is a need for nosological precision so that ultimately those in need can be helped by translating the scientific evidence established in the context of Internet addiction into actual clinical practice.

Research into frequent, excessive, and compulsive social network activity has increased the last years, in which terms such as “social network site addiction” and “Facebook addiction” have been used interchangeably. The aim of this review is to offer more knowledge and better understanding of social network site addiction (SNS-addiction) among researchers as well as clinicians by presenting a narrative overview of the research field in terms of definition, measurement, antecedents, consequences, and treatment as well as recommendations for future research efforts. Seven different measures of SNS-addiction have been developed, although they have to a very little extent been validated against each other. The small number of studies conducted so far on this topic suggests that SNSaddiction is associated with health-related, academic, and interpersonal problems/issues. However such studies have relied on a simple cross-sectional study design. It is therefore hard to draw any conclusions about potential causality and long-term effects at this point, beyond hypothetical speculations. Empirical studies suggest that SNS-addiction is caused by dispositional factors (e.g., personality, needs, self-esteem), although relevant explanatory socio-cultural and behavioral reinforcement factors remain to be empirically explored. No well-documented treatment for SNS-addiction exists, but knowledge gained from Internet addiction treatment approaches might be transferable to SNS-addiction. Overall, the research on this topic is in its infancy, and as such the SNS-addiction construct needs further conceptual and empirical exploration. There is a great demand for studies using careful longitudinal designs and studies which include objective measures of both behavior and health based on broad representative samples.

Exercise and sports activity are beneficial both physically and psychologically but excessive exercise may have adverse physiological and psychological effects. There are methodological issues in the definition, diagnosis and etiology of exercise addiction. Several questionnaires and diagnostic tools have been developed and validated and they show high validity and reliability. Exercise addiction has been suggested as having an obsessive-compulsive dimension as well as rewarding aspects that may include it among the behavioral addictions. Biological studies show that in rodents, exercise such as wheel running activates the dopamine reward system and thus contributing to stress reduction. Further evidence suggests that running is associated with endorphins and cannabinoids thus explaining the “runners high” or euphoric feelings that may lead to exercise addiction. Genetic studies suggest that genes which control preference for drugs also control the preference for naturally rewarding behaviors such as exercise. Psychological studies also explain exercise addiction in terms of reward, habituation, social support, stress-relief, avoidance of withdrawal and reduction of anxiety. It has been suggested that exercise addiction is a part of a continuum of sportive activity that develops in stages from the recreational exercise to at-risk exercise, problematic exercise and finally into exercise addiction. Assessment and treatment should take into account the various stages of exercise addiction development, its comorbidity with other psychiatric disorders such as eating disorders or substance use and alcohol disorders. Treatment approaches for exercise addiction are based on the cognitive-behavioral approach but little is known about their effectiveness. A single-case study shows promise of pharmacological treatment for exercise addiction and further studies are required. This review summarizes diagnostic and phenomenology of exercise addiction with emphasis on physiological and neuro-pharmacological mechanisms responsible for its rewarding and addictive properties.

Background: Socially valorized, excessive indoor tanning can lead to dependence. This finding is based on the observations of many dermatologists, who report repeated failures in preventing their patients from visiting tanning cabins, despite the announcement of a diagnosis of malignant melanoma. Objective: The objective of this paper is to show that excessive indoor tanning can be included in the spectrum of addictive behavior. This review focuses on the clinical features, diagnosis, prevalence, etiology, treatment, prevention, and psychopathology of this disorder. Methods: A review of the medical literature was conducted using PubMed and Google Scholar and using the following key words alone or in combination: tanning, addiction, dependence, tanning bed, sun exposure, and solarium. We selected 41 English-language articles from 1974 to 2013. Results: Many excessive indoor tanners meet symptom criteria adapted from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) substance abuse and dependence criteria. Trial studies suggest that there may be a physiological basis, consisting of dependence on opioids, for excessive indoor tanning behaviors. Conclusion: Excessive indoor tanning can be included in the spectrum of addictive behaviors, although other models may be proposed. Further controlled studies must be performed, especially in neurobiology and imaging, to improve our understanding of tanning dependence.

A growing body of evidence shows that gamma-hydroxybutyric acid (GHB) is an addictive substance. Its precursors gammabutyrolactone (GBL) and 1,4-butanediol (1,4-BD) show the same properties and may pose even more risks due to different pharmacokinetics. There are indications that problematic GHB use is increasing in the European Union. This review investigates the existing literature on the neurochemistry of GHB and its precursors, their acute toxicity, addiction potential and withdrawal, the proposed molecular mechanism underlying addiction and the treatment of withdrawal and addiction. Current evidence shows that GHB and its precursors are highly addictive, both in humans and animals, probably through a GABAB receptor related mechanism. Severity of withdrawal symptoms can be considered as a medical emergency. Recent studies suggest that benzodiazepines are not very effective, showing a high treatment resistance, whereas detoxification with pharmaceutical GHB proved to be successful. However, relapse in GHB use is frequent and more research is warranted on relapse prevention. This might aid medical practitioners in the field and improve general understanding of the severity of addiction to GHB, GBL and 1,4-BD.

Cocaine has become a public health problem. Several studies have shown that cocaine addiction is associated with multiple cognitive damages, such as memory, inhibitory control, attention and executive functions. A French cohort of cocaine addicted patients was divided into two groups: CCU (Current cocaine users) and abstainers. Their cognitive abilities were compared to a control group and associations with clinical determinants were assessed. The CCU group and the abstainers had episodic memory, working memory and inhibitory control disabilities compared to the control group. Both the CCU and the abstainers group had the same cognitive abilities but their clinical determinants for these cognitive abilities differed. In the CCU group, exposure to cocaine seemed to have a negative impact on cognition especially inhibitory control, memory and impulsivity. In the abstainers group, craving and depression impeded cognition.

Background: Although methadone maintenance treatment (MMT) is recognized as the treatment of reference for opioid dependence, little information is available regarding the dynamic adherence to methadone and its determinants. With data from the Methaville trial we investigated the evolution of non-adherence to methadone and the effect of pre-treatment and in-treatment factors on longterm non-adherence to methadone. Methods: We selected 145 patients to study adherence to methadone at 3, 6 and 12 months (M3, M6 and M12, respectively) using a multidimensional questionnaire and a 3-level variable “adherent”/”non adherent”/”highly nonadherent”. We then identified the pre-treatment and in-treatment variables associated with long-term non-adherence to methadone at the M12 visit using a univariate logistic regression and two different multivariate models: the first incorporating only the pre-treatment variables, the second adding the in-treatment variables to the pre-treatment ones. Results: At the M12 visit, 35.2% of the participants remained adherent, 55.9% and 9% were non-adherent and highly non-adherent, respectively. The multivariate analysis of long-term non-adherence to methadone showed 4 pre-treatment predictors and 1 in-treatment predictor as follows: being female, not having stable housing, alcohol consumption, cocaine use and perceiving methadone dose as inadequate. Conclusions: Our findings highlight that pretreatment predictors are important to consider when starting maintenance treatment for opioid dependence, such as cocaine use and problematic alcohol consumption but also low socio-economic levels. In addition, during maintenance treatment, in-treatment predictors such as methadone dose adequacy is a crucial issue to achieve good adherence to MMT.

New designer drugs (synthetic cannabinoids and synthetic cathinones) are new “legal highs” that are sold online for recreational public or private use. Synthetic cannabinoids are psychoactive herbal and chemical products that mimic the effects of cannabis when used. These drugs are available on the Internet or in head shops as incense or air fresheners to circumvent the law. Cathinone is a naturally occurring beta-ketone amphetamine analog found in the leaves of the Catha edulis plant. Synthetic cathinones are phenylalkylamine derivatives that may possess amphetamine-like properties. These drugs are sold online as bath salts. Designer drugs are often labeled as “not for human consumption” to circumvent drug abuse legislation. The absence of legal risks, the ease of obtaining these drugs, the moderate cost, and the availability via the Internet are the main features that attract users, but the number of intoxicated people presenting with emergencies is increasing. There is evidence that negative health and social consequences may affect recreational and chronic users. The addictive potential of designer drugs is not negligible.

Cannabis remains the most commonly used and trafficked illicit drug in the world. Its use is largely concentrated among young people (15- to 34-year-olds). There is a variety of cannabis use patterns, ranging from experimental use to dependent use. Men are more likely than women to report both early initiation and frequent use of cannabis. Due to the high prevalence of cannabis use, the impact of cannabis on public health may be significant. A range of acute and chronic health problems associated with cannabis use has been identified. Cannabis can frequently have negative effects in its users, which may be amplified by certain demographic and/or psychosocial factors. Acute adverse effects include hyperemesis syndrome, impaired coordination and performance, anxiety, suicidal ideations/tendencies, and psychotic symptoms. Acute cannabis consumption is also associated with an increased risk of motor vehicle crashes, especially fatal collisions. Evidence indicates that frequent and prolonged use of cannabis can be detrimental to both mental and physical health. Chronic effects of cannabis use include mood disorders, exacerbation of psychotic disorders in vulnerable people, cannabis use disorders, withdrawal syndrome, neurocognitive impairments, cardiovascular and respiratory and other diseases.