The Assessment and Treatment of Addiction

Best Practices and New Frontiers

Itai Danovitch, Larissa Mooney

• Publisher: Elsevier
• Year: 2018
• Print ISBN: 9780323548564
• eBook ISBN: 9780323548571
• Topic: Medicine
• Subtopic: Psychiatry & Mental Health

Get a quick, expert overview of all types of addiction – from substance use disorders to behavioral addictions and more. This practical resource presents a focused summary of today's current knowledge on topics of interest to all health care professionals who work with those who suffer from this wide-ranging problem. It provides current, relevant information on emerging findings, best practices, and treatment challenges, covering a variety of assessment and treatment strategies and making it a one-stop resource for staying up to date in this critical area.- Discusses precision health in addiction; the latest trend of electronic cigarettes; state-of-the-art treatments for opioid use disorder and cannabis use disorder; best practices for chronic pain; prevention among adolescents; the role of physicians in the prescription drug epidemic; and the role of integrative interventions in addiction treatment.- Includes coverage of behavioral addictions such as internet, sex, and gambling; food addiction; PTSD and substance use disorders; preventing relapse; the neurobiology of addiction; and more.- Consolidates today's available information on this timely topic into one convenient resource.

Section I

Emerging Findings

Outline

Chapter 1. Neurochemical Imaging in Addiction: How Science Informs Practice

Chapter 2. The Role of Nutrition in Addiction Recovery: What We Know and What We Don't

Chapter 3. E-Cigarettes

Chapter 4. The Neuropsychoendocrinology of Substance Use Disorders

Chapter 5. Technological Innovations in Addiction Treatment

Chapter 1

Neurochemical Imaging in Addiction

How Science Informs Practice

Jonathan M. Wai, MD, Frances R. Levin, MD, and Diana Martinez, MD

Abstract

Addiction is characterized by uncontrollable drug intake that is clinically distinct from the occasional use of addictive substances. Neurochemical imaging has increased the understanding of the neurobiological effects of chronic drug administration in humans and how the neurochemistry of individuals may predispose or reinforce patients to continue drug use. In this chapter, we review the significant neurochemical imaging findings in humans with addiction and consider how these findings may inform future treatments. All addictions have been found to affect the dopaminergic system, generally with decreased dopamine receptor affinity and decreased dopamine transmission. Studies of other neurotransmitter systems, such as the serotonergic, opioid, and GABAergic systems, have had less consistent findings. Assessment or modulation of the dopaminergic system is a possible approach for future addiction treatments.

Keywords

Alcohol; Marijuana; Neurochemical imaging; Neuroimaging; Opioids; Stimulants; Substance use disorders

Overview

Substance use disorders are characterized by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as “a cluster of cognitive, behavioral, and physiological symptoms indicating that the individual continues using the substance despite significant substance-related problems”.¹ The diagnostic criteria are further categorized into the symptom clusters of impaired control over use, compulsivity, harmful consequences, and the physiological symptoms of tolerance and withdrawal. These symptoms may persist despite clear negative consequences due to environmental, psychological, or biological reinforcers of behavior. The uncontrollable substance intake that characterizes addiction is clinically distinct from the occasional use of an addictive drug without loss of control,² and current addiction research is focused on characterizing the mechanisms underpinning that distinction. This chapter will review the discoveries of neurochemical imaging studies in human subjects and explore how these findings may translate to treatments for addiction.

Neuroanatomical Structures

A brief review of the neuroanatomical structures most relevant to addiction will aid in understanding the neurochemical imaging literature. These structures have mostly been identified through research using animal models. The nucleus accumbens is located within the ventral striatum and is most closely associated with the reinforcing properties of substances.^3,4 Projections from the ventral tegmental area to the nucleus accumbens shell are important for regulating motivational salience.^5,6 Rewarding events increase dopaminergic release in the accumbens, which reinforces the behaviors that led to the reward.^7,8 The amygdala also receives dopaminergic input from the ventral tegmental area, as well as other input from the prefrontal cortex, nucleus accumbens, brain stem, and hypothalamus.⁹ It is involved in attributing predictors to motivationally salient, or rewarding, events.¹⁰ The prefrontal cortex, particularly the anterior cingulate and ventral orbital cortices, is involved in reward-based decision-making,¹¹ a process that appears to be strongly influenced by the predictability of a reward.^12,13

Neurotransmitters

Dopamine has a central role in mediating reinforced behavior. The mesolimbic dopamine system, which connects the ventral tegmental area in the midbrain to the nucleus accumbens in the ventral striatum, is specifically involved in the reward and reinforcement value of addictive substances.¹⁴ When dopamine is released from the ventral tegmental area in response to novel salient stimuli, this promotes learning and diverts attention to these events.¹⁵ There are 5 subtypes of dopamine receptors (D1-D5), which are further classified into the D1-like (D1 and D5) and D2-like (D2, D3, D4) families.¹⁶ The D1-like receptors act to increase the second messenger cyclic adenosine monophosphate (cAMP), while the D2-like receptors decrease cAMP.¹⁷ Because of the similar properties of these receptors within their respective families and similar behavior in neuroimaging studies, they will be referred to only as D1 or D2 receptors in this chapter.

Changes in dopaminergic signaling in humans were first identified in cocaine addiction by Volkow et al.,¹⁸ but have now been seen in many other addictions, including alcohol, opioid, tobacco, and methamphetamine use disorder. Recent studies have also found impaired dopamine systems in cannabis use disorder. Low D2 receptor binding has been hypothesized to represent a vulnerability to the rewarding effect of pharmacologic rewards over naturally occurring reinforcers.^19,20

Neurochemical Imaging

Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are imaging modalities that can be used to measure receptor density and changes in neurotransmitters in the human brain. The injection of a radioligand, which is a radioactive molecule that binds to a specific receptor, can be detected with PET or SPECT scanners. Radioligands have been developed for a number of different receptors in the brain, such as D1 and D2 dopamine receptors, μ-opioid receptors, serotonergic receptors, and more.

The outcome measure for these brain imaging studies is called the “binding potential” (BP). BP is a measure of the radioligand–receptor complexes in the brain, and it is defined as the product of receptor density (B_max) and the affinity of the radioligand for the receptor (1/K_D)²¹ such that:

BP=BmaxKD=Bmax∗1KD=Bmax∗affinity

However, it is also i...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Managing Challenges in the Assessment and Treatment of Addiction
• Section I. Emerging Findings
• Section II. Best Practices
• Section III. Treatment Challenges
• Index