What is addiction or dependence? Isn’t it just a choice? When does someone cross over from substance use to addiction? What is the cycle of Addiction and the effects on the brain? What are the risk factors to addiction? What is the evidence-based treatment options for addiction? These are common questions many people have concerning substance use disorders and the field of Addiction Medicine. The answers to these questions are not simple and require an exploration into the domains of neurobiology and behavioral science. The more we understand the complexity behind addiction, the easier it will be to reduce the stigma of addiction and to provide effective care and support to those individuals struggling with this difficult condition. Let’s break it down one question at a time.
What is addiction?
Addiction is a chronic, relapsing brain disorder characterized by compulsive drug seeking, continued use of a substance or substances, despite harmful consequences, and long-lasting changes in the brain physiology. Dependence is the term used to describe someone who has brain changes because of their drug use and if they stop using, they will have a reaction such as withdrawal or cravings. Addiction is not a simple lack of willpower, or a moral failing, but rather a complex interplay of genetic, environmental, and neurobiological factors. Genetically, the evidence shows that many genes are associated with familial heredity of different substance disorders, such as alcohol, cocaine, and others. More recent research is focused on the relationship of genes related to our ability to handle stress. Three genes, MAOA, SLC6A4, COMT have been found to be heavily associated with our ability to handle stress. Someone with these genes might respond differently to stressful situations, which can alter how our brain responds to stress and substance use. This could make it easier to become dependent on substances.
Environmental stressors can further cause alterations in our genetic expression. This is called epigenetic change and can add new genetic expression information to existing genetic material. This could lead to a change in the potential for addiction in someone who could use substances without easily triggering an addiction change. Genetics works with neurobiological factors to set the stage for addiction. The neurobiology involves the reward system in the brain, driven by the neurotransmitter Dopamine. The more Dopamine the reward system receives, the more Dopamine the system needs. If there are changes to the reward system that are different than “normal” for the factors we mentioned, then the system becomes unbalanced and does not work correctly.
For instance, let’s consider someone who drinks alcohol on a fairly regular basis but does not have a problem with alcohol causing dysfunction in their life. They use alcohol regularly but responsibly and have no adverse events related to their use. Then later in life their partner dies, or they lose their job and life becomes incredibly stressful. This stress reaction releases glucocorticoids and other hormones, secondary messengers, and inflammation reactions, triggering the regulation of gene expression in the brain. These reactive changes rewire the circuitry in the reward center of the brain, making it harder for this person to stop drinking alcohol. A spiral begins and the more stress they feel, the more they drink, even when the alcohol use creates other problems in their life. Treatment will help, but even after treatment, facing continued significant stressors will cause a struggle with relapse.
When does a person cross over from substance use to addiction/dependence?
The transition from substance use to addiction varies among individuals and involves many factors. Certain factors may increase the likelihood of developing addiction, including genetic predisposition, early exposure to substances, and co-occurring mental health disorders. The progression towards addiction is often marked by escalating use of substances, increasing tolerance of the substance, withdrawal signs and symptoms, and an inability to control substance use despite adverse consequences. The Diagnostic and Statistical Manual 5-TR (DSM-V-TR) uses this progression to diagnose the change from substance use to substance use disorder.
Understanding the cycle of addiction and its underlying brain functions is crucial in comprehending the mechanisms driving compulsive drug seeking and use. Let’s explore this in more detail. The cycle typically begins with the initial exposure to a substance or behavior that activates the brain’s dopamine regulated reward system, leading to feelings of pleasure or euphoria. This is known as the Initial Exposure section of the cycle. This evolves into what is called continued use. Continued use of the substance causes repeated exposure to the substance, leading to neuroadaptive changes in the brain. These changes result in increased tolerance over time, driving the need for increased amounts of the substance to achieve the desired effects. This continued use when done despite adverse consequences is the hallmark of addiction. Next is Craving and Withdrawal. Over the course of time, persons struggling with substance use disorders may experience strong cravings and withdrawal symptoms when the abused is not available.
These cravings are driven by changes in the regulation of neurotransmitter systems, particularly dopamine, which plays a key role in the brain’s reward center. As the cycle continues, we arrive at the Loss of Control phase. In this phase, despite efforts to cut down or stop substance abuse, individuals often find themselves unable to control their cravings or impulses. Disruptions in the brain’s prefrontal cortex, responsible for decision-making and impulse control, contribute to this loss of control. The final phase of the Addiction cycle is Relapse. Relapse is built-in to the struggle of addiction. The cyclical nature of addiction, with periods of abstinence followed by periods of relapse and use underscores the chronic quality of addiction and the need for ongoing support and treatment. The repeated cycling of use, abstinence, and relapse continue to erode the proper regulation of dopamine increasing the risk of other dysfunctions related to neurotransmitter dysregulation, such as depression, cognitive decline, and some inflammatory autoimmune disorders.
What are the risk factors to addiction?
Several risk factors predispose individuals to addiction, including genetic vulnerability, early exposure to substances, co-occurring mental health disorders, trauma, and environmental influences such as peer pressure and socioeconomic status. Additionally, factors such as chronic stress, adverse childhood events (ACEs), and a lack of positive social support can exacerbate the risk of addiction development.
What are some of the evidence-based treatment options? Fortunately, there are evidence-based treatments available for addiction that address both the biological and psychosocial aspects of substance use disorders. These include Medication-Assisted Treatment (MAT): MAT involves the use of medications such as methadone, buprenorphine, and naltrexone to reduce cravings, alleviate withdrawal symptoms, and prevent relapse in those with Opioid Use disorder (OUD) or Alcohol Use disorder (AUD). Behavioral therapies are another tool that has demonstrated robust changes in the thinking and behavior patterns in those with SUDs. Cognitive Behavioral Therapy (CBT), Contingency Management, and Motivational Interviewing are among the therapies proven effective in treating addiction.
These types of therapeutic interventions help individuals identify and modify maladaptive thought processes and behaviors, develop healthier coping strategies, and enhance motivation for change. Integrated care programming addresses both SUD and any co-occurring mental health disorders and is essential for comprehensive care. This may involve collaboration with mental health professionals, social workers, and other healthcare providers to address the complex needs of individuals with substance use disorders. Peer Support Groups: Peer support groups such as Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) provide valuable social support, encouragement, and accountability to individuals in recovery. Family Therapy: Involving family members in the treatment process can enhance social support, improve communication, and address family dynamics that may contribute to substance abuse and addiction.
Addiction, dependence, substance use disorders, regardless of the name used, it is a multifaceted and complex disorder characterized by compulsive drug seeking, continued use despite adverse consequences, and profound changes in brain structure, neurotransmitter regulation, and overall function. The cycle of addiction is driven by neurobiological mechanisms, including alterations in the brain’s reward pathway and impaired impulse control. Recognizing the risk factors associated with addiction and implementing evidence-based treatment approaches are crucial steps in addressing this public health crisis. As healthcare professionals, let’s continue to advocate for comprehensive, compassionate care for individuals struggling with addiction, and do our part to reduce the stigma that interferes with their quality of care.
Dr. C.J. Rush D.O., M.S.(MedEd), CCHP
Chief Psychiatric Officer