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  • Writer's pictureDr. Soroosh Hashemi, M.D.

What Is Addiction?

Updated: Jan 21


What has always drawn me to this field is its pathology. Addiction involves the deep structures of our brain, the more primitive and less autonomous parts of our consciousness.

I would posit that a craving for your favorite food involves the same pathway as a craving for heroin. I would theorize that love itself is a form of addiction.

The deep brain structures I’ve referenced are essential parts of the Limbic system, which regulates homeostasis, olfaction, memory, and emotion. Dopamine is involved, but I believe its role is overemphasized.

There are countless other neurotransmitters involved: serotonin, norepinephrine, glutamate, and many more that we don’t yet know much about. The brain has specific receptors for opioid like compounds and endogenous opioids, such as enkephalins and endorphins. Cannabinoids, as well, have their own set of receptors. I would suggest other substances have their own unique pathways as well. 

I have had some success using medications that alter brain chemistry for the short-term treatment of addiction. This is, however, most useful when patients have been self medicating for underlying mental health conditions. Though psychiatric conditions and past trauma are often involved in the pathology of addiction, they are not always the culprit. I think we all know someone who grew up under happy circumstances, with good parents and a stable environment, who still ended up with a substance use disorder.

The truth is, for most of us, drugs and alcohol feel good. This invokes our reward pathway, with the limbic system sending positive signals to the rest of the brain. The frontal and prefrontal cortex get involved, which results in reinforcing thought patterns which approve of the new substance. The autonomic system gets involved, which results in calmer vital signs. The result is euphoria. We all need a form of release, and in truth, substances are the quickest and perhaps easiest way to achieve one. But they can also be the most destructive.

When the substance is removed from a person’s body the systems mentioned above, and perhaps a number that I failed to mention, go haywire. The limbic system, in the absence of its normal stimulus, begins sending negative signals. The cerebral cortex changes thought processes resulting in cravings and depression. The autonomic system becomes overstimulated. This is why withdraw can be so rough.

I think this is perhaps most evident in the treatment of opioid withdraw. I have seen patients with opioid use disorder scream, become rude, punch holes in walls, and become violent. They are not bad people. Their bodies are caught in sympathetic overdrive.

The good news is the brain is malleable. Thought processes, limbic, and autonomic feedback can change over time. New stimulus responses can be formed. This can be positive, as patients can form newer, healthier associations. But can also be harmful, as people can find themselves addicted to new substances or in intense, toxic relationships.

Over time, change is very possible. It takes work, commitment, and in many cases short-term courses of medications which partially and steadily stimulate the pathways in crisis. There are many paths to recovery. It’s a personal journey.

I have found my involvement with addiction medicine, and my work treating addictions to be highly rewarding. I see patients grow and change. I see their lives go from unmanageable to productive and happy. I see them complete their courses of medication and therapy and go on to live happy independent lives, as long as they stay vigilant and dedicated to change.

I have also had the privilege to learn about myself and the human condition. We have all loved and lost. We have all lived through tragedies. We have all had cravings. The feelings we’ve experienced through these difficulties involve imbalances within the same pathways I mentioned. I try to remember this when interacting with people suffering from substance use disorders, and I think the world would be a better place if we all did.





Soroosh Hashemi, M.D.

Medical Director

Hashemi Healthcare

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