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Etiology of addiction
Etiology of Substance Use Disorders
Lindsey Rasmussen
Physiological Complications and Psychopharmacology
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Etiology of addiction
Addiction is a very complex disease. No single theory can completely explain why people
use drugs or why some become addicted; therefore controversy exists as to the origin, nature,
and boundaries of addiction. It has been said to be everything from a bad habit, a failure of
willpower or morality, a symptom of other problems, to a chronic disease (Hanson, Venturelli,
& Fleckenstein, 2012, p.57-58). Generally, the term addiction refers to a dependence on drugs;
this dependence may be physical and/or psychological, but includes features such as tolerance,
withdrawal, and compulsive behavior. It is important to note that the definition of addiction
can vary depending on the source. The DSM IV defines addiction as substance dependence –
continued drug use despite significant substance related problems. On the other hand, the
National Institute on Drug Abuse (NIDA) defines addiction as a “chronic, relapsing brain disease
characterized by drug seeking and use, despite harmful consequences”. NIDA further explains
that addiction is a disease of the brain because the use of drugs changes the structure and
functioning of the user’s brain and these changes last for a long time and often result in harmful
behaviors seen in the people who abuse them (Hanson et al., 2012, p.59).
There are three models of addiction, each of which gives a different reason why people
abuse substances. The models are: moral, disease, and character/personality disposition. The
moral model explains addiction as the result of poor morals and lifestyle choices exhibited by
those under the influence of drugs. The disease model, which is the prevailing concept of
addiction in the U.S., proposes addiction as a chronic and progressive disease where the user
doesn’t have control over their use and/or abuse of the drug(s). Lastly, the character or
personality disposition model states that addiction is the result of problems in the development
of the addict’s system of needs, motives, and attitudes (Hanson et al., 2012, p.59). The one
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Etiology of addiction
concept that appears universal among the various models, explanations, and theories of
addiction, is its pattern, which includes the following “stages”: initiation, escalation,
maintenance, dysfunction, recovery, ex-addict (“Explaining Drug Use & Abuse PowerPoint, slide
14).
Just as there are different models, there are different explanations and theories of
addiction, each of which specifies certain conditions that increase one’s vulnerability of
becoming addicted. These explanations are: biological, psychological, and sociological. No
single theory can adequately explain every case of addiction, nor does the mere presence of
specific conditions or risk factors make someone an addict. Rather, it is the interaction of many
different elements that determines whether someone becomes addicted or not.
The biological explanation of addiction suggests drug use begins from physical
characteristics (i.e. genetics, brain dysfunction, and/or biochemical patterns) that lead certain
individuals to experiment with or crave drugs to the point of abuse (Hanson, Venturelli, &
Fleckenstein, 2012, p.63). This can be explained in terms of the brain’s reward center; it is
believed that some people have reward centers that are especially sensitive to drug use, which
makes using them more pleasurable or rewarding. Other facets of the biological explanation
posit that drug abuse is a kind of “self-medication” for individuals with psychiatric disorders
looking to relieve their symptoms and research somewhat supports this claim; drug abuse and
mental illnesses often co-occur within the same individual.
Overall, the biological explanation of addiction is strongly backed by research, such as
observations of increased frequency of alcoholism and drug abuse among children of alcoholics
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Etiology of addiction
and drug users. This is further supported by adoption studies that have found children of
alcoholics are likely to grow up to be alcoholics themselves, even if they are raised by nonalcoholic parents. In general, these studies estimate that genetic factors responsible for the
vulnerability to addiction are responsible for 38% of all cases, but that environmental and social
factors account for the remainder (Hanson et al., 2012, p.67). Therefore, biological factors
significantly contribute to the development of addiction but cannot fully explain its spectrum.
The psychological explanation of addiction involves the mental and/or emotional states
of the user, which like biological factors, can be exacerbated by environmental and/or social
factors. Psychological explanations of addiction include the following: blind compliance with
drug-using peers, boredom, conscious and/or unconscious ignorance of the harmful effects of
drug use, destructive self-indulgence, a desire to escape reality, inability to cope with feelings
such as anxiety, as well as self-destructiveness (Hanson et al., 2012, p.67). The psychological
explanation also relies heavily on learning theory, which explains that people learn to use drugs
through the close association of a significant reinforcing stimulus with a less significant or
neutral stimulus (i.e. drug use). It is through this conditioning process that drug use can then
become a habitual pattern of behavior. The American Psychiatric Association (APA) even
classifies the severe dependence on drugs as a psychiatric disorder as well as acknowledging
that drug abuse can also cause symptoms or conditions that mimic major psychiatric illnesses
(Hanson et al., 2012, p.88).
There is some research which supports the psychological explanation of addiction. For
example, studies have found that patterns of introversion and extroversion are associated with
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Etiology of addiction
levels of neural arousal in brain circuits. Furthermore, these forms of arousal are associated
with the effects of certain drugs. As a result, it is thought that these high- and low-arousal
symptoms can be created by drug use and the possibility exists that these personality patterns
(introversion and extroversion) affect how a person reacts to drugs (Hanson et al., 2012, p.69).
It can be concluded that, in some instances, certain psychological conditions (for example,
personality ‘type’) combined with specific biological factors (i.e. neuronal arousal) results in
addiction for some individuals. However, as with other explanations of addiction, it is apparent
that more research is needed for a more complete understanding of how the interaction of
these various elements results in addiction for some but not for others.
The sociological explanation of addiction can also be explained in part, by learning
theory; however, the psychological explanation focuses on internal states of the user, whereas
the sociological explanation focuses on external forces that affect drug use, such as social and
structural influences. Social influence explains that drug use is caused by an individual’s daily
social interactions, whereas structural influence views drug use as a result of societal
organization. Overall, the sociological perspective believes that the motivation to use drugs is
based on the type and quality of bonds that an individual generally has (Hanson et al., 2012,
p.71). Though individual differences exist, research in this area has yielded 14 characteristics
that people who use drugs have in common. Some examples are: (7) a social setting in which
drug use is common; (8) drug-induced behaviors and drug-related attitudes of peers are strong
predictors of subsequent drug involvement; (11) family structure has changed; and (13) among
minorities, feeling powerless due to discrimination (Hanson et al., 2012, p.76-78).
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Etiology of addiction
As previously stated, no one explanation, theory, or even risk factor can adequately
explain the complex disease of addiction or answer the question of why most people use drugs
but only some become addicted. People differ from one another on many different levels and
addiction can only be explained through the interaction of many different factors or conditions
– biological, psychological, sociological, environment, etc. In other words, the complex etiology
of addiction reflects the complexity of human nature and individual differences. Therefore,
possessing or expressing a vulnerability to or risk factors of addiction does not mean an
individual is destined to be an addict. Environment plays a key role, which is best illustrated by
the study of twins. Researchers are able to more accurately assess what roles environment and
biology play, as well as how significant each of their roles may be through their use of twin
studies.
Legrand, Iacono, & McGue, M. (2005) examined what conditions (biochemical, social,
and environmental) encourage or inhibit the expression of “addiction genes” based on a study
of nearly 1400 pairs of twins, observed from ages 11 (17 for second group) to ages 23 to 29
respectively. Legrand and colleagues came to a suggestive conclusion; the inheritable risk of
addiction may be nonspecific, in other words, what is passed down from parent to child is a
tendency toward a group of behaviors, of which addiction is one possible outcome. For
example, childhood characteristics that indicate future alcohol problems also point to a full
range of problematic behaviors and traits, such as antisocial behavior, behavioral problems,
hyperactivity, and illicit drug problems. Therefore, it becomes even more apparent that
behavior is strongly influenced by the environment, though genes and presumably
psychological elements certainly play a role as well. Additionally, even traits with a strong
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Etiology of addiction
genetic component can be influenced by environment; studies of identical twins support this as
well. However, many questions regarding these various interactions remain unanswered.
In addition to the three explanations of addiction (biological, psychological, and
sociological) there are also four widely accepted risk factors of addiction: (1) genes; (2) early
use; (3) social environment; and (4) childhood trauma (“Why Do Some People Become
Addicted?” website).
Genes have a significant role in determining addiction. For example, having parents with
alcoholism makes a person 4 times more likely than other children to become alcoholic.
Likewise, it is estimated that 60% of alcoholics have a family history of alcoholism. Early use
refers to just that. The younger a person starts using alcohol and/or drugs, the higher their
likelihood of moving on to more serious abuse. In other words, early use of substances
indicates a higher likelihood of addiction later in life. Additionally, a person’s social
environment also has a significant role in the development (or not) of addiction. People who
live, work, etc. where drug use is common are more likely to use and/or abuse drugs. This is
also noted as a characteristic of drug users within the sociological explanation of addiction.
Lastly, the risk factor of childhood trauma is closely related to the biological explanation of
addiction. According to this factor, trauma affects a child’s brain chemistry which subsequently
leads to a vulnerability to addiction.
It becomes evident that there is significant overlap between the explanations of and risk
factors for addiction. However, it is important to keep in mind that susceptibility, whether it be
due to the presence of risk factors or indications of biological, psychological, and/or sociological
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Etiology of addiction
elements previously described, does not equate to the inevitability of addiction (“Genetics is
Important Factor in Addiction” website). Addiction is the result of complex relationships and
interactions of many different variables, only some of which research is beginning to accurately
identify.
I believe addiction is a chronic and progressive disease. It is expressed by compulsive
behavior which results from changes in brain structure and function due to repeated use of
drugs. Addiction begins with the voluntary behavior of initial drug use which then, potentially
because of a genetic predisposition that has been exacerbated by various psychological,
sociological, environmental, and/or experiential elements, quickly progresses into a pattern of
addictive behavior that the addict cannot stop by willpower alone (“Addiction is a Brain
Disease” website). Thus treatment of addiction needs to be as sophisticated and complex as the
disease itself. Put another way, addictive behavior needs to be addressed in the context of the
addict’s personal interplay of biological, psychological, sociological, and environmental
elements.
Therefore, instead of bitterly debating the etiology of addiction, we should attempt to
set personal beliefs and opinions aside and instead focus on early intervention and treatment
models that work. Because no matter what the causes of addiction are, people are going to
continue to use, abuse, and ultimately become dependent upon drugs, resulting in a pattern of
addiction that is difficult to break no matter what the causes are, or aren’t.
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Etiology of addiction
References
Explaining drug use and abuse. [PowerPoint slides]. Retrieved from
http://www.morainepark.edu.
Hanson, G. (2012). Genetics is an important factor in addiction. Retrieved from
http://www.learn.genetics.utah.edu.
Hanson G. R., Venturelli, P. J., & Fleckenstein, A. E. (2012). Drugs and society (11th ed.).
Burlington, MA: Jones & Bartlett Learning.
Legrand, L., Iacono, W., & McGue, M. (2005, March-April). Predicting addiction: Behavioral
genetics uses twins and time to decipher the origins of addiction and learn who most is
vulnerable. American Scientist, 93(2). 140-148.
Leshner, A. (2012). Addiction is a brain disease. In Issues in science and technology: Online.
Retrieved from http://www.issues.org.
Why do some people become addicted? Retrieved from http://www.hbo.com/addiction.