Addiction And The Brain

Addiction and the brain are closely related, as addiction is a debilitating neurobehavioral disorder. It is a chronic and relapsing mental health condition that greatly impedes a person’s ability to function in daily life. Therefore, it is crucial to understand the underlying neural mechanisms of addiction for developing comprehensive and effective prevention, treatment, and recovery strategies.

Is Addiction A Brain Disease?

The medical perception of addiction has evolved through the ages. While addiction was once thought to be a moral failing or a lack of willpower, research has shown that it is actually a disease that affects the brain.

As a developmental brain disease [mfn] Berridge K. C. (2017). Is Addiction a Brain Disease?. Neuroethics, 10(1), 29–33. https://doi.org/10.1007/s12152-016-9286-3 [/mfn], it is characterized by progressive changes in the brain’s structure and function [mfn] Koob, G. F., & Volkow, N. D. (2016). Neurobiology of addiction: a neurocircuitry analysis. The lancet. Psychiatry, 3(8), 760–773. https://doi.org/10.1016/S2215-0366(16)00104-8 [/mfn] that alter how the brain responds to reward, motivation, and impulse control.

These changes are also associated with altered behaviors, negative thought patterns, and impaired decision-making processes. Such disabilities can lead to a persistent craving for drugs or other addictive behaviors and the inability to control drug use or behavior. Because of this, addiction is also marked as a behavioral and impulse control disorder [mfn] Devoe, D. J., Anderson, A., Bahji, A., Singh, M., Patten, S. B., Soumbasis, A., Ramirez Pineda, A., Flanagan, J., Richardson, C., Lange, T., Dimitropoulos, G., & Paslakis, G. (2022). The Prevalence of Impulse Control Disorders and Behavioral Addictions in Eating Disorders: A Systematic Review and Meta-Analysis. Frontiers in psychiatry, 12, 724034. https://doi.org/10.3389/fpsyt.2021.724034 [/mfn].

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Which Parts Of The Brain Does Addiction Affect?

Addiction affects multiple parts of the brain [mfn] Herman, M. A., & Roberto, M. (2015). The addicted brain: understanding the neurophysiological mechanisms of addictive disorders. Frontiers in integrative neuroscience, 9, 18. https://doi.org/10.3389/fnint.2015.00018 [/mfn], including:

• The reward system [including the ventral tegmental area (VTA) and the nucleus accumbens (NAc)] that regulates pleasure, motivation, and reinforcement.
• The prefrontal cortex (PFC) that processes decision-making and impulse control.
• The amygdala that processes emotions, including stress and anxiety.
• The hippocampus that processes memory and learning.
• The basal ganglia that regulates motor control and habit formation.

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What Happens In The Brain During Addiction?

Addiction is a complex disorder that involves various neurochemical and molecular changes in the brain. Different types of addiction, such as drug addiction, alcohol addiction, and behavioral addiction, have distinct biochemical and neurobiological mechanisms [mfn] Volkow, N. D., Fowler, J. S., & Wang, G. J. (2003). The addicted human brain: insights from imaging studies. The Journal of clinical investigation, 111(10), 1444–1451. https://doi.org/10.1172/JCI18533 [/mfn]. However, they all involve changes in the brain’s reward system and other neurotransmitter systems.

Addiction causes significant structural and functional changes in the brain’s reward system, which is responsible for pleasure, motivation, and reinforcement. Dopamine [mfn] Volkow, N. D., Fowler, J. S., Wang, G. J., Swanson, J. M., & Telang, F. (2007). Dopamine in drug abuse and addiction: results of imaging studies and treatment implications. Archives of neurology, 64(11), 1575–1579. https://doi.org/10.1001/archneur.64.11.1575 [/mfn], a neurotransmitter released in response to pleasurable stimuli, plays a crucial role in addiction.

Repeated exposure to drugs or addictive behaviors can lead to changes in the brain’s reward system, making it less sensitive to natural rewards and more responsive to drug-related stimuli.

The key brain regions affected by addiction [mfn] US Department of Health and Human Services. (2016, November). THE NEUROBIOLOGY OF SUBSTANCE USE, MISUSE, AND ADDICTION. Nih.gov; US Department of Health and Human Services. Available from: https://www.ncbi.nlm.nih.gov/books/NBK424849/ [/mfn] are the ventral tegmental area, nucleus accumbens, and prefrontal cortex . The release of dopamine in the NAc in response to drug-related stimuli reinforces drug-seeking behavior, leading to continued drug use despite negative consequences.

Additionally, the PFC, which is responsible for decision-making and impulse control, is less active in people with addiction, contributing to poor decision-making and a lack of impulse control. Moreover, other molecular changes in the brain [mfn] Fowler, J. S., Volkow, N. D., Kassed, C. A., & Chang, L. (2007). Imaging the addicted human brain. Science & practice perspectives, 3(2), 4–16. https://doi.org/10.1151/spp07324 [/mfn] that occur during addiction include changes in gene expression, protein synthesis, and neuroplasticity.

How Does Addiction Affect The Brain?

Addiction induces structural and functional changes in the brain that reinforce drug-seeking behavior. This, in turn, interferes with the brain’s [mfn] Gould T. J. (2010). Addiction and cognition. Addiction science & clinical practice, 5(2), 4–14. [/mfn]:

• Behavior related to seeking pleasure, motivation, and reinforcement
• Decision-making and impulse control
• Ability to process and express emotions
• Memory center
• Learning abilities
• Sensitivity to stress and anxiety
• Motor control abilities
• Habit forming tendencies

Addiction also causes changes in the size and shape of certain brain regions, neurodegeneration, and brain aging, making the brain susceptible to mental health conditions [mfn] Shantna, K., Chaudhury, S., Verma, A. N., & Singh, A. R. (2009). Comorbid psychiatric disorders in substance dependence patients: A control study. Industrial psychiatry journal, 18(2), 84–87. https://doi.org/10.4103/0972-6748.62265 [/mfn] like:

• Chronic anxiety
• Depression
• Psychosis
• Antisocial behavior

Can addiction also be rewarding to the brain?

Addiction can initially be rewarding to the brain through the drug-induced activation of the reward system and the release of dopamine. This reinforcement can create a cycle of addiction, making it difficult for individuals to experience pleasure from other activities. The affected person will seek out the drug or addictive behavior to experience the reinforcement provided by the reward system [mfn] Gale, J. T., Shields, D. C., Ishizawa, Y., & Eskandar, E. N. (2014). Reward and reinforcement activity in the nucleus accumbens during learning. Frontiers in behavioral neuroscience, 8, 114. https://doi.org/10.3389/fnbeh.2014.00114 [/mfn].

However, over time, the reward system becomes less responsive to natural rewards. In fact, full-blown addictions are considered reward deficit and stress surfeit disorders [mfn] Koob G. F. (2013). Addiction is a Reward Deficit and Stress Surfeit Disorder. Frontiers in psychiatry, 4, 72. https://doi.org/10.3389/fpsyt.2013.00072 [/mfn].

The Brain In Addiction Recovery

Despite addiction causing structural and functional changes in the brain, the brain has the ability to adapt and recover through a process of neuroplasticity [mfn] O’Brien C. P. (2009). Neuroplasticity in addictive disorders. Dialogues in clinical neuroscience, 11(3), 350–353. https://doi.org/10.31887/DCNS.2009.11.3/cpobrien [/mfn] (or the creation of new neural pathways and the strengthening of existing ones).

This process can help to reverse some of the changes in the reward system, prefrontal cortex, amygdala, hippocampus, and basal ganglia. Neuroplasticity during addiction treatment and recovery [mfn] Eddie, D., Bates, M. E., & Buckman, J. F. (2022). Closing the brain-heart loop: Towards more holistic models of addiction and addiction recovery. Addiction biology, 27(1), e12958. https://doi.org/10.1111/adb.12958 [/mfn] can be promoted through various approaches, including:

• Behavioral therapies [mfn] McHugh, R. K., Hearon, B. A., & Otto, M. W. (2010). Cognitive behavioral therapy for substance use disorders. The Psychiatric clinics of North America, 33(3), 511–525. https://doi.org/10.1016/j.psc.2010.04.012 [/mfn], such as cognitive-behavioral therapy (CBT) and contingency management
• Medications [mfn] Ray, L. A., Meredith, L. R., Kiluk, B. D., Walthers, J., Carroll, K. M., & Magill, M. (2020). Combined Pharmacotherapy and Cognitive Behavioral Therapy for Adults With Alcohol or Substance Use Disorders: A Systematic Review and Meta-analysis. JAMA network open, 3(6), e208279. https://doi.org/10.1001/jamanetworkopen.2020.8279 [/mfn] that reduce drug cravings and withdrawal symptoms
• Exercise
• Mindfulness meditation and stress management techniques
• Nutritional support and lifestyle modification

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Takeaway

At the core of addiction lies the brain’s reward system, making it a primarily neural phenomenon. As a chronic, relapsing disease, addiction is a complex clinical condition that involves the brain undergoing structural and functional changes that trigger modified behavioral and thought patterns.

This can be particularly debilitating for affected individuals and their loved ones. So, it is necessary to focus on the role of the brain in addiction, so it can be worked towards reducing the harm caused by this pervasive disease.

At A Glance

1. Addiction is a complex disorder that involves various neurochemical and molecular changes in the brain.
2. It largely involves dopamine dysfunction and structural and functional changes in the brain’s circuitry (especially the reward system).
3. Other changes in the brain that occur during addiction include changes in gene expression, protein synthesis, and neuroplasticity.
4. These changes collectively reinforce drug-seeking behavior, leading to continued drug use despite negative consequences.
5. Different types of addiction have distinct biochemical and neurobiological mechanisms.

Frequently Asked Questions (FAQs)