Binge eating and psychostimulant addiction

Many of the various factors, characteristics, and variables involved in the addictive process can determine an individual’s vulnerability to develop drug addiction. Hedonic eating, based on pleasure rather than energy needs, modulates the same reward circuits, as do drugs of abuse. According to the last report of the World Health Organization, the worldwide obesity rate has more than doubled since 1980, reaching especially critical levels in children and young people, who are overexposed to high-fat, high-sugar, energy-dense foods. Over the past few decades, there has been an increase in the number of studies focused on how eating disorders can lead to the development of drug addiction and on the comorbidity that exists between the two disorders. Herein, we review the most recent research on the subject, focusing especially on animal models of binge eating disorders and drug addiction. The complex profile of patients with substance use and binge eating disorders requires an integrated response to dually diagnosed patients. Nutritional patterns should be considered an important variable in the treatment of substance use disorders, and future studies need to focus on specific treatments and interventions in individuals who show a special vulnerability to shift from one addiction to the other.     

Diagnosis and treatment of co-occurring affective disorders and substance use disorders.

There is growing interest in the co-occurrence of mood and substance use disorders. It is clear that co-occurrence of these disorders is common and has an impact on prognosis and course of both disorders. The diagnostic issues at the interface of substance or alcohol use disorders and affective illnesses are particularly difficult because of the substantial symptom overlap between substance intoxication and withdrawal and symptoms of affective disorders. Over the past few years, advances have been made in the treatment of co-occurring disorders. Further investigation of specifically tailored treatments for patients with co-occurring substance use and other mood disorders is underway. Because many advances have been made in pharmacotherapy of mood disorders in the past 10 years, this progress will impact individuals with co-occurring disorders, because newer agents with less toxicity and fewer adverse effects and interactions with substances of abuse will be evaluated for treating the comorbid condition. Specific considerations in choosing a pharmacologic agent for use in patients with substance use disorders include safety, toxicity, and abuse liability. Although there are few studies specifically targeting pharmacotherapy for co-occurring disorders, those that have been conducted indicate that similar pharmacotherapeutic agents work for mood disorders with or without substance use disorders. In conclusion, although the co-occurrence of substance abuse and mood disorders is an important area in which recent developments provide cause for considerable optimism, much work remains to be done.     

Chromatin regulation in drug addiction and depression

Alterations in gene expression are implicated in the pathogenesis of several neuropsychiatrie disorders, including drug addiction and depression, increasing evidence indicates that changes in gene expression in neurons, in the context of animal models of addiction and depression, are mediated in part by epigenetic mechanisms that alter chromatin structure on specific gene promoters. This review discusses recent findings from behavioral, molecular, and bioinformatic approaches that are being used to understand the complex epigenetic regulation of gene expression in brain by drugs of abuse and by stress. These advances promise to open up new avenues for improved treatments of these disorders.     

Glial mechanisms underlying substance use disorders

Addiction is a devastating disorder that produces persistent maladaptive changes to the central nervous system, including glial cells. Although there is an extensive body of literature examining the neuronal mechanisms of substance use disorders, effective therapies remain elusive. Glia, particularly microglia and astrocytes, have an emerging and meaningful role in a variety of processes beyond inflammation and immune surveillance, and may represent a promising therapeutic target. Indeed, glia actively modulate neurotransmission, synaptic connectivity and neural circuit function, and are critically poised to contribute to addictive‐like brain states and behaviors. In this review, we argue that glia influence the cellular, molecular, and synaptic changes that occur in neurons following drug exposure, and that this cellular relationship is critically modified following drug exposure. We discuss direct actions of abused drugs on glial function through immune receptors, such as Toll‐like receptor 4, as well as other mechanisms. We highlight how drugs of abuse affect glia‐neural communication, and the profound effects that glial‐derived factors have on neuronal excitability, structure, and function. Recent research demonstrates that glia have brain region‐specific functions, and glia in different brain regions have distinct contributions to drug‐associated behaviors. We will also evaluate the evidence demonstrating that glial activation is essential for drug reward and drug‐induced dopamine release, and highlight clinical evidence showing that glial mechanisms contribute to drug abuse liability. In this review, we synthesize the extensive evidence that glia have a unique, pivotal, and underappreciated role in the development and maintenance of addiction.     

Sex differences in drug abuse

Sex differences are present for all of the phases of drug abuse (initiation, escalation of use, addiction, and relapse following abstinence). While there are some differences among specific classes of abused drugs, the general pattern of sex differences is the same for all drugs of abuse. Females begin regularly self-administering licit and illicit drugs of abuse at lower doses than do males, use escalates more rapidly to addiction, and females are at greater risk for relapse following abstinence. In this review, sex differences in drug abuse are discussed for humans and in animal models. The possible neuroendocrine mechanisms mediating these sex differences are discussed.     

Neural and psychological mechanisms underlying compulsive drug seeking habits and drug memories – indications for novel treatments of addiction

This review discusses the evidence for the hypothesis that the development of drug addiction can be understood in terms of interactions between Pavlovian and instrumental learning and memory mechanisms in the brain that underlie the seeking and taking of drugs. It is argued that these behaviours initially are goal‐directed, but increasingly become elicited as stimulus–response habits by drug‐associated conditioned stimuli that are established by Pavlovian conditioning. It is further argued that compulsive drug use emerges as the result of a loss of prefrontal cortical inhibitory control over drug seeking habits. Data are reviewed that indicate these transitions from use to abuse to addiction depend upon shifts from ventral to dorsal striatal control over behaviour, mediated in part by serial connectivity between the striatum and midbrain dopamine systems. Only some individuals lose control over their drug use, and the importance of behavioural impulsivity as a vulnerability trait predicting stimulant abuse and addiction in animals and humans, together with consideration of an emerging neuroendophenotype for addiction are discussed. Finally, the potential for developing treatments for addiction is considered in light of the neuropsychological advances that are reviewed, including the possibility of targeting drug memory reconsolidation and extinction to reduce Pavlovian influences on drug seeking as a means of promoting abstinence and preventing relapse.     

Mood‐related central and peripheral clocks

Mood disorders, including major depression, bipolar disorder, and seasonal affective disorder, are debilitating disorders that affect a significant portion of the global population. Individuals suffering from mood disorders often show significant disturbances in circadian rhythms and sleep. Moreover, environmental disruptions to circadian rhythms can precipitate or exacerbate mood symptoms in vulnerable individuals. Circadian clocks exist throughout the central nervous system and periphery, where they regulate a wide variety of physiological processes implicated in mood regulation. These processes include monoaminergic and glutamatergic transmission, hypothalamic–pituitary–adrenal axis function, metabolism, and immune function. While there seems to be a clear link between circadian rhythm disruption and mood regulation, the mechanisms that underlie this association remain unclear. This review will touch on the interactions between the circadian system and each of these processes and discuss their potential role in the development of mood disorders. While clinical studies are presented, much of the review will focus on studies in animal models, which are attempting to elucidate the molecular and cellular mechanisms in which circadian genes regulate mood.     

Different explanatory models for addictive behavior in Turkish and German youths in Germany: significance for prevention and treatment

Due to cultural and social barriers, immigrants seldom frequent centers for information, counseling, and treatment of addictive disorders. We examine cultural differences in the explanatory models of addictive behavior among Turkish and German youths in Germany with statistical devices that map the concepts associated with problems of addiction. Relevant differences were found between the disorder concepts of Turkish and German youth. German but not Turkish youths classified eating disorders among severe addictive disorders and associated them with embarrassment and shame. Concerning substance abuse, German but not Turkish youths clearly differentiated between illegal drug abuse and the abuse of alcohol and nicotine. Nearly half of all Turkish youths rejected central medical concepts such as "physical dependence" or "reduced control of substance intake" as completely inadequate to characterize problems of addictive behavior. Preventive information programs must consider these differences and use concepts that are accepted and clearly associated with addictive behavior by immigrant populations.     

Dopamine and Oxytocin Interactions Underlying Behaviors: Potential Contributions to Behavioral Disorders

Dopamine is an important neuromodulator that exerts widespread effects on the central nervous system (CNS) function. Disruption in dopaminergic neurotransmission can have profound effects on mood and behavior and as such is known to be implicated in various neuropsychiatric behavioral disorders including autism and depression. The subsequent effects on other neurocircuitries due to dysregulated dopamine function have yet to be fully explored. Due to the marked social deficits observed in psychiatric patients, the neuropeptide, oxytocin is emerging as one particular neural substrate that may be influenced by the altered dopamine levels subserving neuropathologic‐related behavioral diseases. Oxytocin has a substantial role in social attachment, affiliation and sexual behavior. More recently, it has emerged that disturbances in peripheral and central oxytocin levels have been detected in some patients with dopamine‐dependent disorders. Thus, oxytocin is proposed to be a key neural substrate that interacts with central dopamine systems. In addition to psychosocial improvement, oxytocin has recently been implicated in mediating mesolimbic dopamine pathways during drug addiction and withdrawal. This bi‐directional role of dopamine has also been implicated during some components of sexual behavior. This review will discuss evidence for the existence dopamine/oxytocin positive interaction in social behavioral paradigms and associated disorders such as sexual dysfunction, autism, addiction, anorexia/bulimia, and depression. Preliminary findings suggest that whilst further rigorous testing has to be conducted to establish a dopamine/oxytocin link in human disorders, animal models seem to indicate the existence of broad and integrated brain circuits where dopamine and oxytocin interactions at least in part mediate socio‐affiliative behaviors. A profound disruption to these pathways is likely to underpin associated behavioral disorders. Central oxytocin pathways may serve as a potential therapeutic target to improve mood and socio‐affiliative behaviors in patients with profound social deficits and/or drug addiction.     

Natural and complementary therapies for substance use disorders

PURPOSE OF REVIEW: To review recent studies that have examined the efficacy of natural and complementary therapies as treatments for substance use disorders and their complications. RECENT FINDINGS: Despite increasing interest in natural and complementary therapies for substance use disorders, rigorous clinical studies in this area are few in number. Recent clinical studies, although preliminary, have reported potential therapeutic effects for hypericum in the treatment of smoking cessation, for prickly pear extract in the prevention of alcohol hangover and magnesium supplementation as an adjunct to methadone treatment. Other clinical studies have reported negative findings for ginkgo as an adjunctive treatment for cocaine dependence, for artichoke in prevention of alcohol hangover, and acupuncture for alcohol withdrawal. Relevant findings from animal studies are also discussed. Neither vitamin E nor Liv 52 had a useful effect in alcohol-related liver disease. A study of silymarin in baboons, which was undertaken in an attempt to untangle the conflicting findings of human studies, reported a potential for this compound to prevent liver injury. There is increasing awareness of safety issues associated with complementary therapies. Safety issues pertinent to substance use treatment are discussed in this review. SUMMARY: Several pharmacological and psychosocial treatments for substance use disorders are solidly evidence-based and improve both individual and public health outcomes. At this stage, there remains insufficient evidence to support the use of natural and complementary therapies as a primary intervention for substance use disorders. Further clinical trials are required to clarify the potential role of particular agents.     

Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake

[Avena, N.M., Rada, P., Hoebel B.G., 2007. Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neuroscience and Biobehavioral Reviews XX(X), XXX-XXX]. The experimental question is whether or not sugar can be a substance of abuse and lead to a natural form of addiction. "Food addiction" seems plausible because brain pathways that evolved to respond to natural rewards are also activated by addictive drugs. Sugar is noteworthy as a substance that releases opioids and dopamine and thus might be expected to have addictive potential. This review summarizes evidence of sugar dependence in an animal model. Four components of addiction are analyzed. "Bingeing," "withdrawal," "craving" and "cross-sensitization" are each given operational definitions and demonstrated behaviorally with sugar bingeing as the reinforcer. These behaviors are then related to neurochemical changes in the brain that also occur with addictive drugs. Neural adaptations include changes in dopamine and opioid receptor binding, enkephalin mRNA expression and dopamine and acetylcholine release in the nucleus accumbens. The evidence supports the hypothesis that under certain circumstances rats can become sugar dependent. This may translate to some human conditions as suggested by the literature on eating disorders and obesity.     

Exploring the Relationships between Spirituality and Personality Disorder Traits among a Sample of In-Patients in Treatment for Substance Use Disorder

Personality disorders (PD) complicate the treatment of individuals with substance use disorders. Spirituality has been shown to be a protective factor in the treatment of addiction but very little research has explored how spirituality may differ among individuals in treatment for substance use issues who present with clinical and non-clinical levels of PD traits. This study examined the relationship between spirituality and PD traits among 305 clients recruited from a residential substance abuse treatment center. Results indicated that the existential well-being dimension of spirituality was a statistically significant predictor of most PD trait levels. In addition, the religious well-being dimension was a statistically significant predictor of Narcissistic traits. However, the clinical significance of these results may be limited due to the relatively low amount of variance in PD trait levels explained by the spirituality dimensions. Clinical implications for the treatment of individuals experiencing comorbid PDs and substance use disorders were discussed highlighting the potential benefit of focusing on therapeutic techniques that would help these clients develop existential well-being in their lives rather than a relationship with a Higher Power.     

Mixing Oil and Water: Integrating Mental Health and Addiction Services to Treat People with a Co-occurring Disorder

Treatments for people with the co-occurring disorders of mental illness and substance use (abuse or dependence) have been evolving and improving since the mid 1980s. During this period substance abuse treatment programs reported between 50 and 75% of the people they served also had a mental health problem. At the same time, mental health programs reported between 20 and 50% of the people they served had a co-occurring problem of substance use or abuse. The proposed solution is to integrate the two treatment systems so as to treat both disorders at the same time. During the 1990s integrated treatment was proposed and several models of integrated care were evaluated. The fallacy of these conceptualizations is that the authors of these models presume that the numerous treatment interventions from both treatment traditions are compatible. This is a critical assumption. What if the two are not compatible? Rather than integrate the two systems of mental health and addiction treatment in whole, I would argue, a model is needed that selects the best interventions from each field and discard the rest. Suggestions are presented here for a beginning inventory of best practice interventions that could be the foundation for effectively treating people with co-occurring disorders.     

Computer addiction: implications for nursing psychotherapy practice

TOPIC: Nurse psychotherapists will encounter the impact of today's technology on the daily lives of people including computer addiction. Computer addiction may also present with comorbidities such as depression, gambling, substance abuse, and marital infidelity and divorce. PURPOSE: This overview article presents what is currently documented in the literature regarding the incidence, symptomatology, and nursing psychotherapy interventions relevant to computer addiction and its treatment. Issues presented include computer addiction, virtual relationships, online marital infidelity, and compulsive online sexual behavior. SOURCES: Review of literature from Medline, Psychoinfo, CINAHL, and current texts. CONCLUSIONS: Given the increased use of computers in today's society, there is the potential for overuse of technology and neglect of others and self as a result of computer addiction. Computer disorders also present themselves as marital or couple discord with the potential for online extramarital affairs and compulsive sexual online behavior. A summary and an assessment tool are provided to guide the nurse psychotherapist in practice.     

La plasticidad sináptica mediada por endocannabinoides y «trastornos por consumo de drogas»

Drugs impact brain reward circuits, causing dependence and addiction, in a condition currently described as substance use disorders. Mechanisms of synaptic plasticity in these circuits are crucial in the development of addictive behaviour, and endocannabinoids, particularly anandamide and 2-arachidonyl-glycerol, participate in normal neuroplasticity. Substance use disorders are known to be associated with disruption of endocannabinoid-mediated synaptic plasticity, among other phenomena. Endocannabinoids mediate neuroplasticity in the short and the long term. In the short term, we may stress «inhibitory» phenomena, such as depolarisation-induced suppression of inhibition and depolarisation-induced suppression of excitation, and such «disinhibitory» phenomena as long-lasting disinhibition of neuronal activity, particularly in the striatum, and suppression of hippocampal GABA release. Drugs of abuse can also disrupt normal endocannabinoid-mediated long-term potentiation and long-term depression. Endocannabinoids are also involved in the development of drug-induced hypofrontality and sensitisation. In summary, substance abuse causes a disruption in the synaptic plasticity of the brain circuits involved in addiction, with the alteration of normal endocannabinoid activity playing a prominent role. This facilitates abnormal changes in the brain and the development of the addictive behaviours that characterise substance use disorders.     

Targeting redox regulation to treat substance use disorder using N‐acetylcysteine

Substance use disorder (SUD) is a chronic relapsing disorder characterized by transitioning from acute drug reward to compulsive drug use. Despite the heavy personal and societal burden of SUDs, current treatments are limited and unsatisfactory. For this reason, a deeper understanding of the mechanisms underlying addiction is required. Altered redox status, primarily due to drug‐induced increases in dopamine metabolism, is a unifying feature of abused substances. In recent years, knowledge of the effects of oxidative stress in the nervous system has evolved from strictly neurotoxic to include a more nuanced role in redox‐sensitive signaling. More specifically, S‐glutathionylation, a redox‐sensitive post‐translational modification, has been suggested to influence the response to drugs of abuse. In this review we will examine the evidence for redox‐mediating drugs as therapeutic tools focusing on N‐acetylcysteine as a treatment for cocaine addiction. We will conclude by suggesting future research directions that may further advance this field.     

Nitrous oxide abuse in perspective.

I present evidence that certain health professionals have a higher liability to drug abuse than does the general population. In view of this, data are presented in which the extremely limited contribution of nitrous oxide to this problem is assessed. I demonstrate on the basis of the limited published data now available that pure nitrous oxide addiction is very rare among health professionals, being the rarest drug of abuse among them. When used by the latter, it is most commonly part of a polydrug abuse pattern, not being a major component of the addiction in these cases. It is clear that nitrous oxide addiction is even less of a problem in the general population. Furthermore, after almost 200 years of use, its very minor addictive potential should by now have clarified itself. It would appear that it is unlikely to become, has never been, nor is it the moment of any real significance as a drug of abuse when compared with the many currently available addictive drugs, which clearly pose a much more serious problem.     

Anxiety, Substance Use, and Their Co-Occurrence: Advances in Clinical Science

Research and clinical literatures are replete with examples that psychological disorders are related to drug use, abuse, and dependence. The preponderance of scientific work addressing relations among psychopathological processes and drug use, abuse, and dependence has been focused primarily on psychotic disorders, major depression, antisocial personality disorder, and attention deficit hyperactivity disorder. This corpus of empirical work has indicated that there are clinically meaningful relations among particular types of psychopathology and the onset and maintenance of substance use behaviors and disorders and, in turn, that substance use and use-related problems can impact vulnerability for psychopathology. Within this public health context, it is striking that despite the fact that anxiety disorders are one of the most common classes of psychological problems (Kessler et al., 2005), there has been limited programmatic study of the relations between anxiety vulnerability processes and substance use disorders.     

Neuroimaging bei Substanzabhängigkeit

The use of neuroimaging techniques in research on substance abuse disorders has advanced our understanding of the underlying pathophysiological and neuropsychological mechanisms. While initial structural imaging techniques were applied to investigate substance abuse-related cerebral atrophy, the functional techniques of SPECT, PET, and later fMRT and MRS provide a much broader range of possible research in this field. Besides their use in characterizing the pharmacology of abused substances and their relations to the pathophysiology of substance abuse disorders, they have also played an essential role in examining the neuropsychiatric underpinnings of the illness and their manifestation in changes of cerebral metabolism. Here, the influence of these techniques on the developing picture of substance abuse disorders is discussed by examining areas of particular scientific interest and reviewing exemplary findings.     

Future directions in preventing relapse to substance abuse among clients with severe mental illnesses

The authors review the literature on substance use disorders among persons with severe mental illnesses, including the other papers in this special section on relapse prevention, and suggest future directions. Although prevention of relapse to substance abuse has a well-developed theoretical and empirical base, this perspective has rarely been applied to persons with co-occurring severe mental illness. Research indicates that clients with co-occurring disorders are highly prone to relapse to substance abuse, even after they have attained full remission. Their risk factors include exacerbations of mental illness, social pressures within drug-using networks, lack of meaningful activities and social supports for recovery, independent housing in high-risk neighborhoods, and lack of substance abuse or dual diagnosis treatments. The evidence in hand suggests several steps: developing healthy and protective environments that are experienced as nurturing of recovery; helping people make fundamental changes in their lives, such as finding satisfying jobs, abstinent friends, networks of people who are in the process of recovery, and a sense of meaning; providing specific and individualized treatments for mental illnesses, substance use disorders, and other co-occurring problems; and developing longitudinal research on understanding and preventing relapse that addresses social context as well as biological vulnerabilities and cognitive strategies.