Drug Use and Addiction: Causes, Brain Chemistry, and Recovery

Introduction

Extensive work and research has been done in an effort to understand the impetus for drug use and addiction among adults, children, and adolescents. Thus far, the extensive body of research has proven that, at best, drug addiction is an individual affliction at the heart of which lies a multitude of social, familial, and physical reasons as to why people use drugs, abuse them, and become addicted. Many researchers have concluded that the choice or compulsion driving an individual's drug use, abuse, and subsequent addiction is rooted in the history of the individual's family dynamics, especially his or her early formative years (Nurco, Blatchley, Hanlon, O'Grady, & McCarren, 1998, p. 37).

While some researchers stop at the claim that drug addiction is simply the body's craving and compulsion for the stimulating high that the body has physically and psychologically adjusted to as a result of reckless behavior (Morse, 2006, p. 164), other researchers look for signs of innate or genetic anomalies that might predispose an individual to addiction — and therefore, perhaps, a genetic "switch" that could alter that individual's predisposed behavioral pattern even before they become a drug user or addict (p. 164). This paper attempts to examine these and other bodies of research evidence surrounding the phenomenology of drug abuse and addiction in order to gain insight into the forces that drive that behavior.

Using mice, Dr. Greg Mark studied one of America's most tragic and dangerous drugs, methamphetamine (Ling, 2006, documentary film). Attempting to understand what has become one of the most commonly used illicit drugs, Mark found that the mice who became addicted to "meth" demonstrated drug-seeking behavior, making numerous checks at the source of the drug and becoming anxious and excited when the drug was delayed (Ling, 2006). As the mice were weaned off the drug, Mark noted that when they experienced high levels of stress in their environments, they returned to drug-seeking behavior, going back to the source spot of the drug to alleviate their anxiety (Ling, 2006).

The Sociology, Psychology, and Physiology of Addiction

What this study suggests is that even when the individual's body has been physically cleansed of the toxic drug, the psychology of the drug continues to serve as a catalyst for resuming abusive behavior. This behavior can operate at a subconscious level — a compulsion that drives the individual back to the drug. In this case, Mark identified stress as a precipitator for the motivation that causes individuals to resume drug use, which leads to addiction because of the physiology associated with addictive substances.

Whether it is meth, cocaine, heroin, or other illicit drugs — and even those prescribed legally — the physiology of a drug's impact on the body is well understood. In her book Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis, Denise B. Kandel (2002) examines the theory surrounding the developmental stages and sequences of drug use leading to addiction (p. 3). Kandel references her own study (1975) and the research conducted by Hamburg, Kraemer, and Jahnke (1975), which gave rise to the notion of hierarchical stages of drug addiction, beginning with the use of alcohol and/or tobacco (p. 3). In this hierarchical sequence, illicit drugs follow the legal ones: marijuana, cocaine, methamphetamines, and heroin (p. 3). By introducing the body to legal drugs, and through prolonged use of tobacco and alcohol, the premise holds that an individual is in effect conditioning their body for the next level of abuse (p. 3).

R. J. DeGrandpre and Warren K. Bickel (1993) examined stimulus control and drug dependence (p. 650). They quote Bickel and Kelly (1988) and Ludwig, Stark, and Wikler (1974) in providing a definition for the concept of stimulus control and drug dependence (p. 650). As they explain:

"Stimulus control of drug taking refers to the ability of exteroceptive or interoceptive stimuli to exert control over behavior such that the presence of these stimuli increases the probability of drug use (Bickel & Kelly, 1988). Ludwig, Wikler, and Stark (1974) summarized this control by stating that: Obviously any therapeutic approach, whether it be insight, behaviorally or pharmacologically orientated, that does not recognize the powerful, evocative effects of interoceptive and exteroceptive stimuli ... and that neglects to provide techniques for modifying the strength of these effects will likely be destined for failure."

DeGrandpre and Bickel (1993) continue: "According to the definitions above, the development of drug dependence must stem in part from an increase in the range of stimuli that come to control drug use and a decrease in the likelihood of occurrence of nondrug-related behaviors in the presence of these settings (i.e., a narrowing of the behavioral repertoire). The prospect of such a shift in stimulus control is the focus of this paper" (p. 650). This framework takes into account both the psychology and the physicality of the pattern of dependence and addiction.

Jean-Pierre Changeux (1998) wrote about the body's physical reaction to illicit drugs in the journal Daedalus (p. 145). A drug's impact on human neurotransmitters is measurable. The human brain consists of hundreds of billions of nerve cells, or neurons (p. 145). There are approximately 10,000 connections per neuron running through the axonal and dendritic processes (p. 145). These connectors serve as the pathways for the transmission of the drug and result in a euphoric state of mind (p. 145). Regarding the synaptic gaps between neurons, Changeux states:

"While Ramon y Cajal initially proposed that neurons are independent and contiguous units, electron microscopy showed that at the level of the contacts between neurons, or synapses, the cell membranes do not fuse but are separated by a significant gap. The distances between the cell surface and the conductance of the external medium in the majority of neurons are such that electrical communication cannot take place. Chemical substances, referred to as neurotransmitters, thus relay the electrical impulses to bridge the gap" (p. 145).

It is the complex structure, systems, and reactions of the brain that contribute to the euphoria — the "high" — of drug use and addiction. Changeux describes the brain's role in the euphoric condition as follows:

"When the electrical impulse invades the nerve terminal, the neurotransmitter stored in the ending is released into the cleft as a brief (about one millisecond) high-concentration chemical pulse that diffuses rapidly through the intercellular space until it reaches the next cell membrane. There, the neurotransmitter elicits a response in the form of either a flow of charges across the membrane (thus generating electrical currents) or a set of intracellular reactions (without necessarily being accompanied by a change of electrical properties). In some instances, the distance between the release site and the target of the neurotransmitter becomes relatively large — on a scale of millimeters or even centimeters. To some extent, the mode of communication then resembles that of hormones. In all these instances, the neurotransmitter serves as a critical chemical signal in the communication between nerve cells" (p. 145).

It is within this complex brain system, Changeux says, that "a simple principle emerges for drug action in the brain" (p. 145). Changeux goes on to discuss the way in which stimulant drugs — such as opiates, methamphetamines, cocaine, and heroin — impersonate the chemicals of the brain, causing the brain to react in ways that interrupt its own natural stimuli-to-chemical-release reactions. Most notably, this process causes the neurotransmitter dopamine, which is produced naturally by the brain, to be released artificially (p. 145). Changeux explains:

"Opium contains several active organic molecules, in particular morphine, from which many active analogues have been synthesized; these include heroin (which behaves like morphine) and naloxone (which acts as an antagonist of morphine). Methadone, currently used as a substitute for morphine, bears no obvious chemical relationship to morphine yet was designed on the basis of the three-dimensional structure of the molecule of morphine, and indeed assumes a similar configuration in solution. What principally distinguishes it from morphine is that methadone can be taken orally, without requiring hypodermic needles, thus reducing the risk of infection with either the AIDS or hepatitis virus. The brain does not synthesize morphine but rather a set of endogenous peptides, the opioid peptides, which include the five amino-acid enkephalins and the much-longer endorphins and dynorphin. Structural analogies between the folded peptide and the alkaloid molecules have been thought to explain their similar pharmacological action — analgesia and euphoria, as well as respiratory depression — thereby explaining the danger of overdoses. Opioid drugs, therefore, behave as functional and structural analogs of the endogenous neurotransmitter peptides, including enkephalins, endorphins, and dynorphin" (p. 145).

When a drug impersonates the brain's natural stimuli, causing it to release dopamine, the brain — as is the case with methamphetamine use — will eventually recognize what is happening and respond to the artificial stimuli by shutting down its own dopamine-releasing mechanisms (Ling, 2006).

The Grips of Addiction

Like Mark's mice, the drug addict will always have a response to the precipitators in their life — such as stress — seeking to ease their pain or psychological distress by reaching for their drug of choice. That is because, as Changeux explains, drugs actually target the neurotransmitter receptors (p. 145). More recent studies have yielded new insight into the chemically complex relationship between artificially introduced drugs and the way the brain manufactures its chemicals naturally:

"Chemical investigations now reveal the fine structure of the drug target site at nearly the atomic level. The five subunits that compose the molecule may differ. Two of them, called alphas, were shown by Arthur Karlin from Columbia University to bear the primary responsibility for recognizing acetylcholine or nicotine. Recent work indicates that the drug binding pocket in fact lies at the boundary between an alpha and a nonalpha subunit. There, nicotine, acetylcholine, or even the antagonist curare are firmly captured by at least five (and possibly six) 'fingers' that, as anticipated by Paul Ehrlich at the end of the nineteenth century, establish weak though multiple chemical bonds with the drug" (Changeux, 1998, p. 145).

Regardless of whether the motivation for an individual's drug use and subsequent addiction is social, psychological, or genetic, once the brain has been introduced to the artificial substance, it creates a relationship that tends to engage all of the body's physiological responses toward resumed drug use. In other words, the brain becomes a co-conspirator in drug-seeking behavior, directing the body's cravings toward continued substance use.

Researcher John C. Crabbe offers this perspective on addiction:

"Addiction is a lay term, so everyone assumes he or she knows what it means. However, serious discussions of the basis for the motivational dysregulation of behavior that is its core feature must navigate between languages seeking to describe physiological/pharmacological sources of influence and those focused on intrapsychic events whose basis is unspecified. An interesting review of the field that evaluated this distinction forthrightly concluded that both orientations contribute to our understanding of addiction, and that both structural frameworks can offer predictive value (Davies 1998)" (Crabbe, 2002, p. 435).

The addict's life is consumed with satisfying the need to maintain the euphoria that the brain has caused the person to become accustomed to and to desire. Family, social, employment, and all other aspects of an individual's life tend to be overwhelmed by the need to satisfy the addiction (Ammerman, Ott, & Tarter, 1999). The reversal of drug-seeking behavior is equally consuming, because it requires the addict's total concentration, commitment, and awareness of their precipitators and drug-seeking behaviors (Ammerman et al., 1999). It becomes a life-changing — and lifelong — process that the former addict can never simply walk away from.

Sheila M. Strauss and Gregory P. Falkin (2001) note that drug use among women leading to addiction increased over the preceding decade (p. 241). This is a deeply concerning trend because of its repercussions for society: children being raised by addicts, or equally troubling, children being placed in foster care because their mother is imprisoned for drug-related crimes. Of equal concern is illicit drug use by persons already suffering from mental health conditions, such as schizophrenia, where mixing prescribed medications with drugs like methamphetamines only serves to exacerbate psychosis, jeopardize treatment, and create dangerous conditions for those who come into contact with the individual (Scheller-Gilkey et al., 2003, p. 553).