The Causes of Addiction

Understanding Addiction

Before delving into the causes of addiction, it's essential to first establish what addiction entails and the different forms it can take.

Definition and Overview

Addiction refers to a chronic, relapsing disorder characterized by compulsive drug seeking, continued use despite harmful consequences, and long-lasting changes in the brain. It's considered a disease because it alters the brain structure and function [1].

Substance use disorders, a category of addictions, are a pressing global public health problem, with approximately 246 million people between the ages of 15 and 64 estimated to have used an illicit drug in 2013. Drug use can be attributed to approximately 187,000 deaths in 2013 alone.

Types of Addiction

Addiction is not limited to substances like drugs or alcohol. It can also involve behaviors. Here are some common types of addiction:

1. Substance Addiction: This includes addiction to alcohol, tobacco, prescription drugs, and illicit drugs such as cocaine or heroin. Substance addiction often results in physical dependence, where the body has adapted to the substance and experiences withdrawal symptoms without it.
2. Behavioral Addiction: This involves compulsive engagement in a behavior despite negative consequences. Common behavioral addictions include gambling, food, internet, sex, and video games.
3. Dual Diagnosis: This is when a person has a substance use disorder and another mental health disorder, such as depression, anxiety, or bipolar disorder.

It's important to note that addiction is not a choice or moral failing, but a complex interplay of genetic, environmental, and social factors. Understanding the different types of addiction can help in identifying the root causes of addiction and developing effective treatment strategies.

The Intersection of Mental Health and Addiction

The intricate relationship between mental health and addiction is one of the many aspects under investigation when it comes to understanding the causes of addiction. Often, these two issues coexist, leading to a complex intersection that needs to be addressed for effective treatment.

Co-Occurring Disorders

Co-occurring disorders, also known as dual diagnosis, refer to when a person has both a mental health disorder and a substance use disorder. Common risk factors such as genetic and epigenetic vulnerabilities, issues with similar brain areas, and environmental influences like early exposure to stress or trauma can contribute to both substance use disorders and mental illnesses.

Moreover, substance use can lead to changes in the same brain areas that are disrupted in mental disorders, such as schizophrenia, anxiety, mood, or impulse-control disorders. It's worth noting that drug use preceding the first symptoms of a mental illness may produce changes in brain structure and function that kindle an underlying predisposition to develop that mental illness.

While these co-occurring disorders present a challenge, recovering from mental health problems and substance use disorders requires treating both issues, which may include rehabilitation, medications, support groups, and talk therapy.

Symptoms of Substance Use Disorders

Substance use disorders manifest in several ways and can bring about significant changes in a person's behavior, physical health, and social interactions. Some of the symptoms, as outlined by SAMHSA, include:

• Behavioral changes: Increased aggression or irritability, changes in attitude or personality, lack of motivation, inability to fulfill responsibilities at work, school, or home, and engaging in secretive or suspicious behaviors.
• Physical changes: Changes in appetite or sleep patterns, sudden weight loss or gain, deterioration of physical appearance, and unusual smells on breath, body, or clothing.
• Social changes: Sudden change in friends, favorite hangouts, and hobbies, legal issues related to substance use, and unexplained need for money or financial problems.

Recognizing these symptoms is an essential step in seeking help and initiating the recovery process. It's essential to remember that while these symptoms can be overwhelming, help and support are available, and recovery from substance use disorders is achievable.

Risk Factors for Addiction

Understanding the causes of addiction is a complex task, as it encompasses a variety of contributing factors. These can range from individual circumstances, such as childhood experiences and genetic predispositions, to broader social and environmental conditions.

Childhood and Adolescence

The period of childhood and adolescence is a critical stage in the development of addiction. Various risk factors during this time have been consistently linked to an increased risk for addiction in adulthood. These factors include externalizing and internalizing symptoms, early substance use, and environmental influences such as parental behavior and exposure to traumatic experiences.

A recent meta-analytic review found that a diagnosis in childhood or adolescence of attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD) or oppositional defiant disorder (ODD), and depression, were associated with an increased risk for adult addiction.

Greater levels of externalizing behavior in childhood and adolescence are associated with increased risk for alcohol and cannabis use disorders, as well as nicotine use disorder in adulthood. Additionally, internalizing symptoms during adolescence, specifically depressive symptoms, have been linked to an increased risk for alcohol and nicotine dependence later in life [4].

Genetic and Environmental Influences

The interplay between genetic and environmental factors plays a significant role in the development of addiction. On the genetic front, specific genes can make a person more susceptible to addiction. However, these genetic predispositions do not act in isolation. Environmental variables, such as exposure to drugs or stressful situations, can trigger these genetic vulnerabilities, leading to the development of addiction.

Moreover, epigenetic factors can also contribute to addiction. These are changes in gene expression caused by experiences and environmental factors, rather than changes in the DNA sequence itself. Epigenetic changes can affect a person's response to drugs and their susceptibility to addiction.

Social and Familial Factors

Social and familial factors also significantly contribute to the risk of developing addiction. For instance, parental substance use disorders increase the risk of personal addiction in adulthood, with parental alcoholism during adolescence being linked to alcohol and drug dependence in offspring in adulthood.

Additionally, peer pressure, social norms, societal stressors, and lack of social support can all contribute to the risk of developing addiction. Understanding these risk factors is crucial in developing effective prevention and intervention strategies to combat addiction.

Neurobiological Basis of Addiction

Decoding the causes of addiction involves understanding how substance use affects the brain's structure and functions. This section explores the neurobiological changes that occur with substance use and how these neuroadaptations contribute to the addiction cycle.

Brain Changes and Substance Use

Advances in neuroscience and addiction research have shed light on the neurobiological changes that occur when a person transitions from recreational substance use to a substance use disorder or addiction. Substance use can lead to alterations in the same brain areas that are disrupted in mental disorders, such as schizophrenia, anxiety, mood, or impulse-control disorders. In fact, drug use preceding the first symptoms of a mental illness may produce changes in brain structure and function that kindle an underlying predisposition to develop that mental illness.

Moreover, advances in neuroscience have revealed that addiction involves changes in the brain's reward circuitry, including the basal ganglia and extended amygdala. These changes result in increased incentive salience (the motivational component of reward-related behavior), decreased brain reward, increased stress, and compromised executive function.

Neuroadaptations in Addiction Cycle

Much progress in the neurobiology of addiction can be placed into a heuristic three‐stage addiction cycle framework: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. This framework is supported by multiple neuroadaptations in three corresponding domains: (1) increased incentive salience, (2) decreased brain reward and increased stress, and (3) compromised executive function; and in three major neurocircuits: basal ganglia, extended amygdala, and prefrontal cortex.

The neurobiological basis of addiction can be understood through the three-stage addiction cycle framework, which involves neuroadaptations in the basal ganglia, extended amygdala, and prefrontal cortex. These adaptations contribute to increased incentive salience, decreased brain reward, increased stress, and compromised executive function.

Understanding both the drivers and consequences of substance use in vulnerable populations, including those whose brains are still maturing, has revealed behavioral and biological characteristics that can increase risks of addiction.

The neurobiological basis of addiction underscores the complexity of this condition, revealing it to be a disease that affects both the brain and behavior. By understanding these underlying mechanisms, we can better understand the causes of addiction and develop more effective treatments.

Epidemiology of Addiction

Understanding the demographics and statistics surrounding addiction helps shed light on the scale of the issue. This section will delve into the prevalence of addiction in the U.S. and identify populations that are particularly vulnerable to developing addictions.

Prevalence in the U.S.

Substance use disorders present a significant global public health problem. In 2013, it was estimated that around 246 million people between the ages of 15 and 64 had used an illicit drug. Drug use was attributed to approximately 187,000 deaths in that year alone.

In the U.S., rates of tobacco use were slightly higher for whites compared to African Americans, and lower for Hispanics and Asians. Higher usage was also observed among those with lower educational attainment, those who were unemployed, and those living in rural areas.

Vulnerable Populations

Certain populations exhibit a higher likelihood of developing addiction. For instance, individuals living in areas of concentrated disadvantage and disorder, characterized by low income, low educational attainment, and high unemployment, face higher stress levels and are more prone to substance use, particularly among adolescents.

Likewise, completion rates for substance use disorder treatment show notable disparities by race and socioeconomic status in the U.S. Whites, employed individuals, and those with higher educational attainment generally have a higher likelihood of treatment completion compared to other groups.

Youth identifying as LGBTQ+ also face a heightened risk for substance use due to the stigma and discrimination they often experience. This makes them particularly vulnerable to the causes of addiction. Supportive measures that affirm their identity can help protect them from such risks.

These trends highlight the necessity of tailored, community-based interventions aimed at preventing substance use disorders among vulnerable populations. Understanding these demographics aids in the development of effective strategies to combat the root causes of addiction.

Impact of Substance Use on Mental Health

Substance use significantly affects mental health, leading to changes in both brain structure and function. These changes often align with disruptions seen in various mental disorders. This section will examine the impact of substance use on the brain's architecture and its association with mental disorders.

Brain Structure and Function Changes

Substance use can lead to changes in the same brain areas disrupted in mental disorders such as schizophrenia, anxiety, mood, or impulse-control disorders. The use of drugs preceding the first symptoms of a mental illness may produce changes in brain structure and function that kindle an underlying predisposition to develop that mental illness.

Advancements in neuroscience and addiction research have helped to describe the neurobiological changes that occur when a person transitions from recreational substance use to a substance use disorder or addiction. The understanding of both the drivers and consequences of substance use in vulnerable populations, including those whose brains are still maturing, has revealed behavioral and biological characteristics that can increase the risks of addiction.

Figures courtesy NCBI

Associations with Mental Disorders

Much progress in the neurobiology of addiction can be placed into a heuristic three‐stage addiction cycle framework: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. This framework is supported by multiple neuroadaptations in three corresponding domains: increased incentive salience, decreased brain reward and increased stress, and compromised executive function; and in three major neurocircuits: basal ganglia, extended amygdala, and prefrontal cortex. Neuroadaptations may also play a role in the comorbidity of substance use disorders and other mental illnesses.

Adolescents and young adults are particularly at risk for developing substance use disorders; areas of their brains responsible for evaluating risk, weighing consequences, and making decisions are not fully developed until the mid‐20‐year‐old age range. Individuals who begin using illicit addictive substances earlier in life ultimately consume more addictive substances more frequently and have higher rates of substance use disorders.

These associations underscore the importance of early intervention and prevention efforts to mitigate the risk of substance use disorders and their potential to contribute to the development of mental health issues. Understanding the causes of addiction and its impact on mental health is crucial in developing effective treatment strategies and promoting long-term recovery.

References

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4924064/

‍[2]: https://nida.nih.gov/publications/research-reports/common-comorbidities-substance-use-disorders/why-there-comorbidity-between-substance-use-disorders-mental-illnesses

‍[3]: https://www.samhsa.gov/mental-health/mental-health-substance-use-co-occurring-disorders

‍[4]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7747788/

‍[5]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6767400/

‍[6]: https://drugfree.org/article/risk-factors-for-addiction/