Addiction

Addiction is a brain disorder characterized by compulsive engagement in rewarding stimuli despite adverse consequences.[8] Despite the involvement of a number of psychosocial factors, a biological process – one which is induced by repeated exposure to an addictive stimulus – is the core pathology that drives the development and maintenance of an addiction.[1][9] The two properties that characterize all addictive stimuli are that they are reinforcing (i.e., they increase the likelihood that a person will seek repeated exposure to them) and intrinsically rewarding (i.e., they are perceived as being inherently positive, desirable, and pleasurable).[1][3][7]

Addiction is a disorder of the brain’s reward system which arises through transcriptional and epigenetic mechanisms and occurs over time from chronically high levels of exposure to an addictive stimulus (e.g., eating food, the use of cocaine, engagement in sexual activity, participation in high-thrill cultural activities such as gambling, etc.).[1][10][11] ΔFosB, a gene transcription factor, is a critical component and common factor in the development of virtually all forms of behavioral and drug addictions.[10][11][12][13] Two decades of research into ΔFosB’s role in addiction have demonstrated that addiction arises, and the associated compulsive behavior intensifies or attenuates, along with the overexpression of ΔFosB in the D1-type medium spiny neurons of the nucleus accumbens.[1][10][11][12] Due to the causal relationship between ΔFosB expression and addictions, it is used preclinically as an addiction biomarker.[1][10][12] ΔFosB expression in these neurons directly and positively regulates drug self-administration and reward sensitization through positive reinforcement, while decreasing sensitivity to aversion.[note 1][1][10]

Addiction exacts an “astoundingly high financial and human toll” on individuals and society as a whole.[14][15][16] In the United States, the total economic cost to society is greater than that of all types of diabetes and all cancers combined.[16] These costs arise from the direct adverse effects of drugs and associated healthcare costs (e.g., emergency medical services and outpatient and inpatient care), long-term complications (e.g., lung cancer from smoking tobacco productsliver cirrhosis and dementia from chronic alcohol consumption, and meth mouth from methamphetamine use), the loss of productivity and associated welfare costs, fatal and non-fatal accidents (e.g., traffic collisions), suicides, homicides, and incarceration, among others.[14][15][16][17] Classic hallmarks of addiction include impaired control over substances or behavior, preoccupation with substance or behavior, and continued use despite consequences.[18] Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs).[19]

Examples of drug and behavioral addictions include alcoholismamphetamine addictioncocaine addictionnicotine addictionopioid addictionfood addictiongambling addiction, and sexual addiction. The only behavioral addiction recognized by the DSM-5 and the ICD-10 is gambling addiction. The term addiction is misused frequently to refer to other compulsive behaviors or disorders, particularly dependence, in news media.[20] An important distinction between drug addiction and dependence is that drug dependence is a disorder in which cessation of drug use results in an unpleasant state of withdrawal, which can lead to further drug use.[21] Addiction is the compulsive use of a substance or performance of a behavior that is independent of withdrawal. Addiction can occur in the absence of dependence, and dependence can occur in the absence of addiction, although the two often co-occur.

USA

The United States of America (USA), commonly referred to as the United States (U.S.), America, and sometimes the States, is a federal republic[17][18] consisting of 50 statesand a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is located in the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The country also has five populated and nine unpopulated territories in the Pacific and the Caribbean. At 3.80 million square miles (9.85 million km2)[4] and with around 318 million people, the United States is the world’s fourth-largest country by total area and third-largest by population. It is one of the world’s most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries.[19]The geography and climate of the United States is also extremely diverse, and it is home to a wide variety of wildlife.[20]

The United States is a developed country and has the world’s largest national economy.[6] The economy is fueled by an abundance of natural resources and high worker productivity.[29] While the U.S. economy is considered post-industrial, it continues to be one of the world’s largest manufacturers.[30] The country accounts for 37% of global military spending,[31] being the world’s foremost economic and military power, a prominent political and cultural force, and a leader in scientific research and technological innovations.[32]