addiction addiction addiction is generally a neuropsychological symptom defining pervasive and intense urge to engage in maladaptive behaviors providing immediate sensory rewards (e.g. consuming drugs, excessively gambling), despite their harmful consequences. dependence is generally an addiction that can involve withdrawal issues. addictive disorder is a category of mental disorders defining important intensities of addictions or dependences, which induce functional disabilities. there are no agreed definitions on these terms – see section on 'definitions'. not to be confused with psychological dependence. addictionother namesaddictive behaviour (e.g. substance-use addiction, sexual addiction), dependence, addictive disorder, addiction disorder (e.g. severe substance-use disorder, gambling disorder)brain positron emission tomography images that compare brain metabolism in a healthy individual and an individual with a cocaine addictionspecialtypsychiatry, clinical psychology, toxicology, addiction medicine repetitive drug use alters brain function in ways that perpetuate craving, and weakens (but does not completely negate) self-control. this phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological (and thus involuntary) factors that are implicated in addiction's development. classic signs of addiction include compulsive engagement in rewarding stimuli, preoccupation with substances or behavior, and continued use despite negative consequences. habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs). examples of drug (or more generally, substance) addictions include alcoholism, marijuana addiction, amphetamine addiction, cocaine addiction, nicotine addiction, opioid addiction, and eating or food addiction. alternatively, behavioral addictions may include gambling addiction, internet addiction, social media addiction, video game addiction, pornography addiction and sexual addiction. the dsm-5 and icd-10 only recognise gambling addictions as behavioural addictions, but the icd-11 also recognises gaming addictions. definitions addictions or addictive behaviours, are polysemes defining both a category of mental disorders, neuropsychological symptoms, or merely maldaptive/harmful habits and lifestyles. a common use of addictions in medicine, is as neuropsychological symptoms defining pervasive/excessive and intense urges to engage in a category of behavioural compulsions or impulses towards sensory rewards (e.g. alcohol, betel quid, drugs, sex, gambling, video gaming). addictive disorders or addiction disorders, are mental disorders involving high intensities of addictions (as neuropsychological symptoms) that induce functional disabilities (i.e. limit subjects' social/family and occupational activities), and whose the two addiction categories are substance-use addictions and behavioural addictions. however, there is no agreement on the exact definition of addictions in medicine. indeed, volkow et al. (2016) report that the dsm-5 defines addictions as the most severe degree of the addictive disorders due to pervasive/excessive substance-use or behavioural compulsions/impulses. it is a definition that many scientific papers and reports use. moreover, the icd-11 is ambiguous; it uses addictions both as neuropsychological symptoms and mental disorders, but only in the context of substance use (i.e. not behaviors). indeed, the icd-11 uses in its entries and classification hierarchy, substance-use disorders "due to" substance-use addictions/dependences alongside with the other "symptoms" defining this category of mental disorders (i.e. harmful episodes, harmful patterns, withdrawal issues, intoxication). in this context, it defines addictions as neuropsychological symptoms, just like ocds due to pervasive/excessive obsessions/compulsions, or impulse control disorders due to pervasive/excessive impulses. unfortunately the icd-11 also uses the term " disorder" (only) within the entries on the substance-use addictions/dependences (i.e. alcohol dependence/addiction, cannabis dependence/addiction, etc.), whereas it implicitly or explicitly uses the term "symptoms" for all the other mentioned terms above (which all happen at the same classification-hierarchy level). dependences is also a polyseme defining either neuropsychological symptoms or mental disorders. in the dsm-5, dependences differ from addictions and can even normally happen without addictions; besides, substance-use dependences are severe stages of substance-use addictions (i.e. mental disorders) involving withdrawal issues. in the icd-11, substance-use dependences is a synonym of substance-use addictions (i.e. neuropsychological symptoms) that can but not necessarily involve withdrawal issues. substance addiction main article: substance use disorder further information: substance abuse and substance-related disorder addiction and dependence glossary addiction – a biopsychosocial disorder characterized by persistent use of drugs (including alcohol) despite substantial harm and adverse consequences addictive drug – psychoactive substances that with repeated use are associated with significantly higher rates of substance use disorders, due in large part to the drug's effect on brain reward systems dependence – an adaptive state associated with a withdrawal syndrome upon cessation of repeated exposure to a stimulus (e.g., drug intake) drug sensitization or reverse tolerance – the escalating effect of a drug resulting from repeated administration at a given dose drug withdrawal – symptoms that occur upon cessation of repeated drug use physical dependence – dependence that involves persistent physical–somatic withdrawal symptoms (e.g., fatigue and delirium tremens) psychological dependence – dependence that involves emotional–motivational withdrawal symptoms (e.g., dysphoria and anhedonia) reinforcing stimuli – stimuli that increase the probability of repeating behaviors paired with them rewarding stimuli – stimuli that the brain interprets as intrinsically positive and desirable or as something to approach sensitization – an amplified response to a stimulus resulting from repeated exposure to it substance use disorder – a condition in which the use of substances leads to clinically and functionally significant impairment or distress tolerance – the diminishing effect of a drug resulting from repeated administration at a given dose drug addiction, which belongs to the class of substance-related disorders, is a chronic and relapsing brain disorder that features drug seeking and drug abuse, despite their harmful effects. this form of addiction changes brain circuitry such that the brain's reward system is compromised, causing functional consequences for stress management and self-control. damage to the functions of the organs involved can persist throughout a lifetime and cause death if untreated. substances involved with drug addiction include alcohol, nicotine, marijuana, opioids, cocaine, amphetamines, and even foods with high fat and sugar content. addictions can begin experimentally in social contexts and can arise from the use of prescribed medications or a variety of other measures. drug addiction has been shown to work in phenomenological, conditioning (operant and classical), cognitive models, and the cue reactivity model. however, no one model completely illustrates substance abuse. risk factors for addiction include: aggressive behavior (particularly in childhood) availability of substance community economic status experimentation epigenetics impulsivity (attentional, motor, or non-planning) lack of parental supervision lack of peer refusal skills mental disorders method substance is taken usage of substance in youth food addiction main article: food addiction the diagnostic criteria for food or eating addiction has not been categorized or defined in references such as the diagnostic and statistical manual of mental disorders (dsm or dsm-5) and is based on subjective experiences similar to substance use disorders. food addiction may be found in those with eating disorders, though not all people with eating disorders have food addiction and not all of those with food addiction have a diagnosed eating disorder. long-term frequent and excessive consumption of foods high fat, salt, or sugar, such as chocolate, can produce an addiction similar to drugs since they trigger the brain's reward system, such that the individual may desire the same foods to an increasing degree over time. the signals sent when consuming highly palatable foods have the ability to counteract the body's signals for fullness and persistent cravings will result. those who show signs of food addiction may develop food tolerances, in which they eat more, despite the food becoming less satisfactory. chocolate's sweet flavor and pharmacological ingredients are known to create a strong craving or feel 'addictive' by the consumer. a person who has a strong liking for chocolate may refer to themselves as a chocoholic. risk factors for developing food addiction include excessive overeating and impulsivity. the yale food addiction scale (yfas), version 2.0, is the current standard measure for assessing whether an individual exhibits signs and symptoms of food addiction. it was developed in 2009 at yale university on the hypothesis that foods high in fat, sugar, and salt have addictive-like effects which contribute to problematic eating habits. the yfas is designed to address 11 substance-related and addictive disorders (srads) using a 25-item self-report questionnaire, based on the diagnostic criteria for srads as per dsm-5. a potential food addiction diagnosis is predicted by the presence of at least two out of 11 srads and a significant impairment to daily activities. the barratt impulsiveness scale, specifically the bis-11 scale, and the upps-p impulsive behavior subscales of negative urgency and lack of perseverance have been shown to have relation to food addiction. behavioral addiction main article: behavioral addiction the term behavioral addiction refers to a compulsion to engage in a natural reward – which is a behavior that is inherently rewarding (i.e., desirable or appealing) – despite adverse consequences. preclinical evidence has demonstrated that marked increases in the expression of δfosb through repetitive and excessive exposure to a natural reward induces the same behavioral effects and neuroplasticity as occurs in a drug addiction. addiction can exist in the absence of psychotropic drugs, which was popularized by peele. these are termed behavioral addictions. such addictions may be passive or active, but they commonly contain reinforcing features, which are found in most addictions. sexual behavior, eating, gambling, playing video games, and shopping are all associated with compulsive behaviors in humans and have been shown to activate the mesolimbic pathway and other parts of the reward system. based on this evidence, sexual addiction, gambling addiction, video game addiction, and shopping addiction are classified accordingly. sexual main article: sexual addiction sexual addiction involves an engagement in excessive, compulsive, or otherwise problematic sexual behavior that persists despite negative physiological, psychological, social, and occupational consequences. sexual addiction may be referred to as hypersexuality or compulsive sexual behavior disorder. the dsm-5 does recognize sexual addiction as a clinical diagnosis. hypersexuality disorder and internet addiction disorder were among proposed addictions to the dsm-5, but were later rejected due to the insufficient evidence available in support of the existence of these disorders as discrete mental health conditions. reviews of both clinical research in humans and preclinical studies involving δfosb have identified compulsive sexual activity – specifically, any form of sexual intercourse – as an addiction (i.e., sexual addiction). reward cross-sensitization between amphetamine and sexual activity, meaning that exposure to one increases the desire for both, has been shown to occur as a dopamine dysregulation syndrome. δfosb expression is required for this cross-sensitization effect, which intensifies with the level of δfosb expression. gambling gambling provides a natural reward that is associated with compulsive behavior. functional neuroimaging evidence shows that gambling activates the reward system and the mesolimbic pathway in particular. it is known that dopamine is involved in learning, motivation, as well as the reward system. the exact role of dopamine in gambling addiction has been debated. suggested roles for d2, d3, and d4 dopamine receptors, as well as d3 receptors in the substantia nigra have been found in rat and human models, showing a correlation with the severity of the gambling behavior. this in turn was linked with greater dopamine release in the dorsal striatum. gambling addictions are linked with comorbidities such as mental health disorders, substance abuse, alcohol use disorder, and personality disorders. risk factors for gambling addictions include: antisocial behavior, impulsive personality, male, sensation seeking, substance use, and young age. gambling addiction has been associated with some personality traits, including: harm avoidance, low self direction, decision making and planning insufficiencies, impulsivity, as well as sensation seeking individuals. although some personality traits can be linked with gambling addiction, there is no general description of individuals addicted to gambling. internet main article: internet addiction disorder internet addiction does not have any standardized definition, yet there is widespread agreement that this problem exists. debate over the classification of problematic internet use considers whether it should be thought of as a behavioral addiction, an impulse control disorder, or an obsessive-compulsive disorder. others argue that internet addiction should be considered a symptom of an underlying mental health condition and not a disorder in itself. internet addiction has been described as "a psychological dependence on the internet, regardless of the type of activity once logged on." problematic internet use may include a preoccupation with the internet and/or digital media, excessive time spent using the internet despite resultant distress in the individual, increase in the amount of internet use required to achieve the same desired emotional response, loss of control over one's internet use habits, withdrawal symptoms, and continued