Horizon Blog

Is addiction a disease?

February 9th, 2015

Brain anatomy - cross sectionFor many years, both scientists and the general population were under a misapprehension that drug addicts were morally flawed individuals who simply lacked the willpower to end their compulsive drug use. Thanks to advances in modern science, we now know that drug addiction, whether it is to alcohol, tobacco, or recreational drugs such as marijuana or methamphetamines, is truly a disease of the brain that requires proper medical treatment.

Reclassifying Addiction as a Brain Disease
According to Alan Leshner, MD, brain disease is defined as a condition caused by persistent changes in brain structure and function. What is the relationship between brain disease and addiction? According to the National Institute on Drug Abuse (NIDA), addiction is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences.

Science now tells us that the complexity of addiction is comparable to other types of brain diseases, such as Alzheimer’s disease, schizophrenia, and clinical depression. What sets drug addiction apart, however, is its inception. Drug addiction begins with a voluntary behavior: the cognitive choice to use a drug. Yet what begins as a voluntary choice, over time, becomes a compulsive behavior comparable to the symptoms of other brain diseases. Just as a Parkinson’s patient cannot physically control his trembling, a drug addict cannot control the craving to seek out his drug of choice.

The Biology Behind Addiction
Modern scientists have proven that drugs physically alter the brain of the long-term user. When addiction occurs, it is caused by an array of neuro-adaptive changes and new memory connections in the brain. Most drugs target the brain’s reward system by overproducing dopamine, a neurotransmitter that regulates motivation and feelings of pleasure. Since the human brain is wired for survival, it interprets the feeling of pleasure as a life-saving sensation. When drug use is repeated and levels of dopamine are continually elevated, the brain instructs the addict to repeat whatever behavior caused the sensation. Over time, the addict’s brain is re-wired to crave and seek out continued drug use out of a perceived need for survival.

Understanding the Disease and The Need for Treatment
Our collective misunderstanding of addiction is that since it begins with a voluntary behavior and is expressed in the form of excess behavior, an addict should be able to stop their drug use at his or her own discretion. Now that science has validated that addiction is a disease that requires a biomedical treatment, there is a growing cultural understanding that addicts cannot simply quit at will. Supportive family and friends are realizing that their loved one’s brain has been physically altered by drug use, and that medical intervention through addiction treatment is needed. For many addicts, this patience and support is the first step needed in the road to permanent recovery.


Horizon Health Services is located in Western New York and offers outpatient and inpatient addiction and recovery services. Please visit Horizon’s addiction services page on our website or call us at (716) 831-1800 for more information.

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