Neurobiology of Alcohol and the Brain

Ashok K. Singh

• Publisher: Academic Press
• Year: 2020
• Print ISBN: 9780128196809
• eBook ISBN: 9780128198919
• Topic: Psychology
• Subtopic: Educational Psychology
• Index: Psychology

According to the 2018 National Survey on Drug Use and Health, 14.4 million adults aged 18 and older had alcohol use disorder (AUD). Mixing alcohol with other drugs such as opioids or cocaine has become an emerging trend, exacerbating public health concerns and may synergistically augment the seriousness of the adverse effects such as withdrawal symptoms, cardiovascular disorders, liver damage, reproductive abnormalities, and behavioral abnormalities.Despite the seriousness of the situation, possible mechanisms underlying the addiction and the withdrawal symptoms is not yet understood. This has been one of the key hindrances in developing effective treatment. Neurobiology of Alcohol and the Brain addresses the addiction-related problems reviewing both the mechanisms and withdrawal system with alcohol addiction. First, the book discusses the mechanisms of the rewarding and aversive effects, including addiction and the withdrawal symptoms of alcohol drinking. Next, alcohol's interaction with other drugs and ensuing adverse consequences is discussed including current and novel treatments against alcoholism. This is followed by a closer look at mental health and alcohol use disorder comorbidity. Lastly, the reader is provided with examples of an experimental study that describes possible protective effects of gold nanoparticles against alcohol addiction in rats subjected to alcohol self-administration. Neurobiology of Alcohol and the Brain will unlock the mechanistic diversities of alcoholism helping to facilitate future developments of new, personalized treatment options for patients suffering from alcohol addiction.- Provides an exhaustive overview of neurobiology of alcohol addiction, including significant recent advances- Discusses the mechanisms underlying the adverse effects of alcohol-drug mixtures- Includes recent experimental studies on gold nanoparticles

1: Journey from responsible alcohol drinking to alcoholism

Abstract

Alcoholic beverages are socially accepted around the world and consumed mostly to socialize, celebrate, and relax. The pleasant effects of alcohol are attributed to (i) an increase in GABA_ergic (inhibitory signals), OP_ergic, and 5HT_ergic (euphoric effects) neuronal activities and (ii) a decrease in DA_ergic (“want” signal or craving), Glu_ergic (excitatory signals), and NE_ergic (stress signals) neuronal and the HPA axis (stress hormones) activities. If alcohol drinking continues, the receptors are sensitized, resulting in the development of tolerance when alcohol drinking must be increased to achieve the desired effects. In genetically/environmentally predisposed subjects, chronic alcohol drinking results in the development of addiction, characterized by a condition when alcohol caseation results in a rapid onset of withdrawal symptoms including, but not limited to, alcohol craving and moderate to severe discomfort. Because pharmacotherapy alone or in combination with behavioral approaches are only modestly effective in treating alcoholism symptoms, there is an urgent need for the development of effective and safe therapies. At present, a lack of clear understanding of the mechanisms underlying addiction hinders possible development of new treatment strategies. Therefore, this chapter aims to discuss the mechanisms underlying (i) the euphoric, relaxing, and adverse effects of alcohol drinking and (ii) addiction and the withdrawal symptoms.

Keywords

Acetaldehyde; Alcoholism; Addiction; Epigenetics; Ethanol; Genomics; Pharmacogenomics; Pharmacotherapy; Tolerance; Withdrawal

1: Scope of alcohol abuse

Ethanol (also referred to as alcohol in this book) is the principal psychoactive component of alcoholic drinks [1]. Unlike the illegal psychoactive drugs such as cocaine, amphetamine, and LSD, alcoholic beverages are legal and socially accepted in many parts of the world (Europe > America > Asia and Africa > the Middle East, and other countries where alcohol is banned) (Fig. 1.1, [2]). In the United States, heavy drinking is more common in (i) Middle Atlantic States or New England, (ii) more highly urbanized areas, and (iii) certain national or ethnic origins. Although responsible alcohol drinking induces euphoria and provides relaxation with some medicinal benefits, chronic drinking is associated with the development of addiction, a condition in which alcohol abstinence results in severe withdrawal symptoms that subside upon resumption of alcohol consumption [3,4]. According to a 2014 WHO report, about 7% of the global population (approximately 500 million) and 10% of the US population suffer from alcoholism and drug addiction. Unfortunately, in the United States, an estimated 88,000 people die per year due to alcohol abuse, and only about 11% of those addicted to alcohol receive treatment for their abuse disorder [5]. This suggests a lack of a comprehensive prevention strategy to combat addiction, possibly because the public may not understand its seriousness to individuals and society.

Fig. 1.1 Global alcohol drinking statistics.

Considerable individual differences have been reported in (i) alcohol consumption and ensuing intoxication and (ii) development of addiction (defined as a cluster of behavioral, cognitive, and physiological abnormalities as well as the development of physical withdrawal state upon abstinence) [6]. Studies have shown that only about 6% (9.8 million, 5.3 million women and 623,000 adolescents aged 12–17 years) of alcohol drinkers in the United States aged 18 and above developed alcoholism and other alcohol-related disorders (NIAAA 2008). This is because only genetically predisposed people experiencing socioenvironmental cues develop an addiction in response to persistent drinking [2,3]. Although possible causes for the global and individual differences in alcohol use and rate of addiction are not yet known, a key role of genetic predisposition, socioenvironmental factors (SEFs), and characteristics and formulation of the drug have been implicated (Fig. 1.2) [1].

Fig. 1.2 The degree of response caused by drug use depends on many factors that relate the information about the person taking the drug.

Many risk factors (defined as the factors that increase a person’s chances of developing a disease) such as age, sex, hormonal status, impulsivity, sweet-liking, novelty, reactivity, exercise, environmental impoverishment, mental disorders, aggression, stress, and relief of withdrawal symptoms increase vulnerability to alcohol and other drug abuse [7–10]. Often, different risk factors interact with each other, resulting in an additive vulnerability, thus increasing the predictability that drug abuse will occur. In addition to the risk factors, comorbidity is another factor increasing the vulnerability to alcohol. Comorbidity is the presence of two or more illnesses, simultaneously or sequentially, in the same person. Fig. 1.3 shows the risk factors for alcohol drinking and alcoholism and ensuing comorbid diseases.

Fig. 1.3 Alcoholism risk factors and comorbidity.

Alcohol abuse, in addition to causing aversive reinforcement and addiction, is also an important risk factor for many diseases such as cancer, atrial fibrillation, and hypertension [11–17]. In the United States alone, about 17 million people of different age groups suffer from alcohol-related disorders [18]. This suggests that alcohol abuse may exert tremendous economic consequences not only for the drinking individuals but also on the society at large [19].

Although most people, under normal circumstances, drink alcohol responsibly (limiting to one’s once limit, not getting drunk, not letting alcohol control one’s life or relationships, etc.), certain socioeconomic cues such as stress, dysfunctional family environment, quality of emotional and social ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• 1: Journey from responsible alcohol drinking to alcoholism
• 2: Interaction of alcohol with drugs of abuse and medicines
• 3: Mental health and alcohol use disorder (AUD) comorbidity
• 4: Traditional treatment strategies for alcoholism and the withdrawal symptoms
• 5: Novel nanoparticle-based treatment approaches
• 6: Conclusions
• Index