Learning Objectives
- Describe the biological causes of substance-related and addictive disorders.
- Describe the cognitive causes of substance-related and addictive disorders.
- Describe the behavioral causes of substance-related and addictive disorders.
- Describe the sociocultural causes of substance-related and addictive disorders.
Biological
11.4.1.1. Genetics. Similar to other mental health disorders, substance abuse is genetically influenced. With that said, it is different than other mental health disorders in that if the individual is not exposed to the substance, they will not develop substance abuse.
Heritability of alcohol abuse is among the most well studied substances, likely because it is the only legal substance (except cannabis in some states). Twin studies have indicated a range of 50-60% heritability risk for alcohol disorder (Kendler et al., 1997). Studies exploring the heritability of other substance abuse, particularly drug use, suggests there may be a stronger heritability link than previously thought (Jang, Livesley, & Vernon, 1995). Twin studies indicate that the genetic component of drug abuse is stronger than drug use in general, meaning that genetic factors are more significant for abuse of a substance over nonproblematic use (Tsuang et al., 1996). Merikangas and colleagues (1998) found an 8-fold increased risk for developing a substance abuse disorder across a wide range of substances.
Unique to substance abuse is the fact that both genetic and familial influence are both at play. What does this mean? Well, biologically, the individual may be genetically predisposed to substance abuse; additionally, the individual may also be at risk due to their familial environment where their parents or siblings are also engaging in substance abuse. Individuals whose parents abuse substances may have a greater opportunity to ingest substances, thus promoting drug-seeking behaviors. Furthermore, families with a history of substance abuse may have a more accepting attitude of drug use than families with no history of substance abuse (Leventhal & Schmitz, 2006).
11.4.1.2. Neurobiological. A longstanding belief about how drug abuse begins and is maintained is the brain reward system. A reward can be defined as any event that increases the likelihood of a response and has a pleasurable effect. Most of the research on the brain reward system has focused on the mesocorticolimbic dopamine system, as it appears this area is the primary reward system of most substances that are abused. As research has evolved in the field of substance abuse, five additional neurotransmitters have also been implicated in the reinforcing effect of addiction: dopamine, opioid peptides, GABA, serotonin, and endocannabinoids. More specifically, dopamine is less involved in opioid, alcohol, and cannabis. Alcohol and benzodiazepines lower the production of GABA, while cocaine and amphetamines decrease dopamine. Cannabis has been shown to reduce the production of endocannabinoids.
Cognitive
Cognitive theorists have focused on the beliefs regarding the anticipated effects of substance use. Defined as the expectancy effect, drug-seeking behavior is presumably motivated by the desire to attain a particular outcome by ingesting a substance. The expectancy effect can be defined in both positive and negative forms. Positive expectations are thought to increase drug-seeking behavior, while negative experiences would decrease substance use (Oei & Morawska, 2004). Several studies have examined the expectancy effect on the use of alcohol. Those with alcohol abuse reported expectations of tension reduction, enhanced sexual experiences, and improved social pleasure (Brown, 1985). Additionally, observing positive experiences, both in person and through television or social media, also shapes our drug use expectancies.
While some studies have explored the impact of negative expectancy to eliminate substance abuse, research has failed to continually support this theory, suggesting that positive experiences and expectations are a more powerful motivator of substance abuse than the negative experiences (Jones, Corbin, Fromme, 2001).
Behavioral
Operant conditioning has been implicated in the role of developing substance use disorders. As you may remember, operant conditioning refers to the increase or decrease of a behavior, due to reinforcement or punishment. Since we are talking about increasing substance use, behavioral theorists suggest that substance abuse is positively and negatively reinforced due to the effects of a substance.
Positive reinforcement occurs when substance use is increased due to the positive or pleasurable experiences of the substance. More specifically, the rewarding effect or pleasurable experiences while under the influence of various substances directly impacts the likelihood that the individual will use the substance again. Studies of substance use on animals routinely support this theory as animals will work to receive injections of various drugs (Wise & Koob, 2013).
Negative reinforcement, or the increase of a given behavior due to the removal of a negative effect, also plays a role in substance abuse in two different ways. First, many people ingest a substance as an escape from their unpleasant life—whether it be physical pain, stress, or anxiety, to name a few. Therefore, the substance temporarily provides relief from a negative environment, thus reinforcing future substance abuse (Wise & Koob, 2013). Secondly, negative reinforcement is involved in symptoms of withdrawal. As previously mentioned, withdrawal from a substance often produces significant negative symptoms such as nausea, vomiting, uncontrollable shaking, etc. To eliminate these symptoms, an individual will consume more of the substance, thus again escaping the negative symptoms and enjoying the “highs” of the substance.
Sociocultural
Arguably, one of the strongest influences of substance abuse is the impact of one’s friends and the immediate environment. Peer attitudes, perception of others’ drug use, pressure from peers to use substances, and beliefs about substance use are among the strongest predictors of drug use patterns (Leventhal & Schmitz, 2006). This is particularly concerning during adolescence when patterns of substance use typically begin.
Additionally, research continually supports a strong relationship between second-generation substance abusers (Wilens et al., 2014). The increased possibility of family members’ substance abuse is likely related to both a genetic predisposition, as well as the accepting attitude of the familial environment (Chung et al., 2014). Not only does a child have early exposure to these substances if their parent has a substance abuse problem, but they are also less likely to have parental supervision, which may impact their decision related to substance use (Wagner et al., 2010). One potential protective factor against substance use is religiosity. More specifically, families that promote religiosity may reduce substance use by promoting negative experiences (Galen & Rogers, 2004).
Another sociocultural view on substance abuse is stressful life events, particularly those related to financial stability. Prevalence rates of substance abuse are higher among poorer people (SAMHSA, 2014). Furthermore, additional stressors such as childhood abuse and trauma, negative work environments, as well as discrimination are also believed to contribute to the development of a substance use disorder (Hurd, Varner, Caldwell, & Zimmerman, 2014; McCabe, Wilsnack, West, & Boyd, 2010; Unger et al., 2014).
Key Takeaways
You should have learned the following in this section:
- Biological causes of substance-related and addictive disorders include the brain reward system and a genetic predisposition, though if the individual is not exposed to the substance they will not develop the substance abuse.
- Cognitive causes of substance-related and addictive disorders include the expectancy effect, and research provides stronger support for positive expectancy over negative expectancy.
- Behavioral causes of substance-related and addictive disorders include positive and negative reinforcement.
- Sociocultural causes of substance-related and addictive disorders include friends and the immediate environment.
Review Questions
- Discuss the brain reward system. What neurobiological regions are implicated within this system?
- Define the expectancy effect. How does this explain the development and maintenance of substance abuse?
- Discuss operant conditioning in the context of substance abuse. What are the reinforcers?
- How does the sociocultural model explain substance abuse?
