Introduction to Addiction

Addiction, Animal Models, and Theories

George F. Koob,Michael A. Arends,Mandy L McCracken,Michel Le Moal

• Publisher: Academic Press
• Year: 2019
• ISBN:
  9780128167953
• Topic: Scienze biologiche
• Subtopic: Neuroscienza

Introduction to Addiction, Volume One in the series, introduces the reader to the study of neurobiology of addiction by clearly defining addiction and its neuroadaptational views. This volume includes thorough descriptions of the various animal models applicable to the study of addiction, including Animal Models of the Binge-Intoxication Stage of the Addiction Cycle and Animal Models of Vulnerability to Addiction. The book's authors also include a section on numerous neurobiological theories that aid in the understanding of addiction, including dopamine, prefrontal cortex and relapse.

• Provides neurobiological theories on how addiction works
• Explains addiction cycle stages of binge, withdrawal and anticipation
• Reviews the role of dopamine and the frontal cortex in addiction
• Discusses the neurocircuitry of reward and stress
• Includes animal models and neuroadaptational views on addiction

Chapter 1

What is addiction?

Abstract

This chapter defines addiction as a chronic relapsing disorder that is characterized by compulsive drug seeking, the loss of control in limiting intake, and the emergence of a negative emotional state when access to the drug is prevented. The definition of addiction is derived from evolution of the concept of dependence and the nosology of addiction diagnosis. A distinction is made between drug use and substance use disorders (formerly abuse and dependence), with individuals termed as suffering from “addiction.” Addiction affects a large percentage of society and has enormous monetary costs. Addiction evolves over time, moving from impulsivity to compulsivity and ultimately being composed of three stages—preoccupation/anticipation, binge/intoxication, and withdrawal/negative affect—that worsen over time and involve allostatic changes in the brain reward and stress systems.

Keywords

Allostasis; Binge; Drug addiction; Neurocircuitry; Neuroclinical assessment; VTA

1. 1. Definitions of addiction
   1. 1.1 Drug use, drug abuse, and drug addiction
   2. 1.2 Diagnostic criteria for addiction
   3. 1.3 Frequency and cost of addiction
   4. 1.4 Patterns of addiction
   5. 1.5 The “dependence” view of addiction
   6. 1.6 Psychiatric view of addiction
   7. 1.7 Neurobiological view of addiction
      1. 1.7.1 Binge/intoxication stage: basal ganglia
      2. 1.7.2 Withdrawal/negative affect stage: extended amygdala
      3. 1.7.3 Preoccupation/anticipation stage: prefrontal cortex
2. 2. Neuroadaptational views of addiction
   1. 2.1 Behavioral sensitization
   2. 2.2 Counteradaptation and opponent process
   3. 2.3 Motivational view of addiction
   4. 2.4 Allostasis and neuroadaptation
   5. 2.5 Psychodynamic view of addiction
   6. 2.6 Social psychological and self-regulation views of addiction
   7. 2.7 Vulnerability to addiction
   8. 2.8 Individual differences, neuroclinical assessment, and precision medicine
3. 3. Summary
4. References

1. Definitions of addiction

1.1. Drug use, drug abuse, and drug addiction

Drug addiction is a chronically relapsing disorder that is characterized by (1) compulsion to seek and take the drug, (2) loss of control in limiting intake, and (3) emergence of a negative emotional state (e.g., dysphoria, anxiety, irritability) when access to the drug is prevented [2]. The occasional but limited use of an abusable drug is clinically distinct from escalated drug use, the loss of control over limiting drug intake, and the emergence of chronic compulsive drug seeking that characterize addiction. Historically, three types of drug use have been delineated: (1) occasional, controlled, or social use, (2) drug abuse or harmful use, and (3) drug addiction as characterized as either Substance Dependence (Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV]) or Dependence (International Statistical Classification of Diseases and Related Health Problems, 10th revision [ICD-10]). More current descriptions have elaborated a continuum of behavioral pathology, from drug use to addiction [2], in the context of the substance use disorder construct of DSM-5.

1.2. Diagnostic criteria for addiction

The diagnostic criteria for addiction as described in the DSM have evolved, from the first edition published in 1952 to the DSM-5 [3], with a shift from an emphasis on the criteria of tolerance and withdrawal to other criteria that are more directed at compulsive use. The criteria for Substance Use Disorders in the DSM-IV closely resembled those outlined in the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10), for Drug Dependence ([4]; Table 1). The DSM-5 was published in 2013 [3], and the criteria for drug addiction were changed both conceptually and diagnostically. The new diagnostic criteria for addiction merged the abuse and dependence constructs (i.e., substance abuse and substance dependence) into one continuum that defines “substance use disorders” on a range of severity, from mild to moderate to severe, based on the number of criteria that are met out of 11. The severity of a substance use disorder (addiction) depends on how many of the established criteria are met by an individual. Mild Substance Use Disorder is the presence of 2–3 criteria, moderate is 4–5 criteria, and severe is ≥6 criteria. These criteria remain basically the same as in the DSM-IV and ICD-10, with the exception of the removal of “committing illegal acts” and the addition of a new “craving” criterion. For example, rather than differentiating subjects with alcohol dependence and subjects with alcohol abuse, the DSM-5 classification of Alcohol Use Disorder encompasses individuals who are afflicted by the disorder to different degrees, from “mild” (e.g., a typical college binge drinker who meets two criteria, such as alcohol is often taken in larger amounts or over a longer period than was intended, and there is a persistent desire or unsuccessful efforts to cut down or control alcohol use) to “severe” (e.g., a classic person with alcoholism who meets six or more criteria, such as a great deal of time spent in activities necessary to obtain alcohol, use alcohol, or recover from its effects, recurrent alcohol use resulting in a failure to fulfill major role obligations at work, school, or home, alcohol use despite knowledge of having a persistent or recurrent physical or psychological problem, continued alcohol use despite persistent social or interpersonal problems, tolerance, and withdrawal).

The terms Substance Use Disorder and Addiction will be used interchangeably throughout this book to refer to a usage process that moves from social drug use to compulsive use as defined above. Drug addiction is a disease and, more precisely, a chronic relapsing disease. The associated medical, social, and occupational difficulties that usually develop during the course of addiction do not disappear after detoxification. Addictive drugs produce changes in brain circuits that endure long after the person stops taking them. These prolonged neurochemical and neurocircuitry changes and the associated personal and social difficulties put former patients at risk for relapse. Abstinent rates were 12% in an untreated sample of alcohol-dependent subjects after 1 year [5].

Table 1

DSM-5, DSM-IV, and ICD-10 diagnostic criteria for abuse and dependence.

DSM-5	DSM-IV	ICD-10
Dependence
A problematic pattern of substance use leading to clinically significant impairment or distress, as manifested by at least two of the following occurring within a 12 month period:	A maladaptive pattern of substance use, leading to clinically significant impairment or distress as manifested by three or more of the following occurring at any time in the same 12-month period:	Three or more of the following have been experienced or exhibited at some time during the previous year:
1. Tolerance is defined by either of ...