On Wednesday, "Justice League" star Ben Affleck reportedly entered rehab for alcohol addiction. This is not Affleck's first attempt to get clean. Indeed, the 46-year-old father of three has been public about his ongoing struggle with substance abuse, previously seeking treatment in 2001 and 2017.

Affleck is at least the second high-profile celebrity relapse this summer. Earlier this spring, pop star Demi Lovato tweeted: “Just officially turned 6 years sober. So grateful for another year of joy, health and happiness. It IS possible.” In June, she released her single “Sober,” which seemed to describe a relapse ("We've been down this road before/I'm so sorry, I'm not sober anymore") — a few weeks later, she was hospitalized after a suspected overdose.

Just officially turned 6 years sober. So grateful for another year of joy, health and happiness. It IS possible. — Demi Lovato (@ddlovato) March 15, 2018

Lovato eventually canceled the rest of her tour performances and released a statement emphasizing the long-term nature of addiction. “What I’ve learned is that this illness is not something that disappears or fades with time,” she told followers on Instagram. “It is something I must continue to overcome and have not done yet.”

It was a strikingly similar statement to one Affleck posted on Facebook last year: "I have completed treatment for alcohol addiction; something I've dealt with in the past and will continue to confront. I want to live life to the fullest and be the best father I can be. I want my kids to know there is no shame in getting help when you need it, and to be a source of strength for anyone out there who needs help but is afraid to take the first step."

It’s a problem that’s all too common. Substance use disorder (more commonly known as “drug addiction”) is a never-ending battle. No matter the substance that is being abused, there is no shortcut or magic cure.

Broadly speaking, addiction has become a worldwide health epidemic. This should come as no surprise. According to the World Drug Report (2017), nearly a quarter of a billion people reported using an illicit drug in the past year, with 29.5 million people meeting the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for substance use disorder. Although social stereotypes continue to label addiction as a “choice,” drug use disorder is medical disease that has a biological basis with influences from the environment.

While it is incredibly difficult for individuals with addiction to completely abstain from drugs, the greatest challenge for addicts is often navigating cycles of abstinence and relapse. For example, Lovato’s continual battle with substance abuse disorder dates back to at least 2010, when she was still a teenager. (The former child star, who is also bipolar, said she used to smuggle cocaine onto airplanes.)

The unending nature of addiction has led to the common phrase used in support groups: “once an addict, always an addict.” To truly understand this phrase, though, we have to understand the neurobiological basis for it. Relapses are a result of the brain’s reward circuit rewiring after exposure to addictive drugs. Alterations in these regions lead to monumental transformations in an individual’s perception of rewards (such as drugs, food and social interactions) and motivation. For most people, prioritizing rewards and motivation is relatively easy, so much so that it is often taken for granted. But for an individual with drug use disorder, their brain has been so hijacked by drug exposure that it now evaluates decisions through the lens of how to obtain the next high or the next drink.

Relapses are a result of the brain’s reward circuit rewiring after exposure to addictive drugs. Alterations in these regions lead to monumental transformations in an individual’s perception of rewards and motivation.

So, what can be done? The scientific community is still devoting considerable time and effort to understanding the basis of addiction. There have been great strides in unraveling contributing factors at the cellular level, and yet, our limited comprehension of addiction has led to ineffective treatment methods. Worldwide, for example, recorded overdoses have tripled between 2002 to 2015.

One of the most common current therapies is drug rehabilitation, which aims to provide environments that encourage drug abstinence, and often includes counseling and medication for depression or other disorders. Unfortunately, at some point, individuals must enter back into the real world, where they are once again exposed to environmental cues (such as people and places) that can provoke cravings. Relapses of all kinds can also be triggered by things like stress. Replacement/management therapy is another commonly used treatment method for opioid use disorder that involves replacing an opioid, such as heroin, with a less euphoric and longer acting opioid, such as buprenorphine.

Numerous risk factors can contribute to a person becoming addicted, but it is important to highlight that substance use disorder does not discriminate based on age, gender, race, or socioeconomic status. More importantly, all the money and support in the world cannot buy a lifetime of guaranteed abstinence. In her statement, both Lovato and Affleck acknowledged this, with Lovato noting that she “will keep fighting” and Affleck writing that his addiction is something he "will continue to confront."

Like Lovato, Affleck and the many others — famous or not, who continue to work towards sobriety — we as a society must constantly remind ourselves that addiction doesn’t end. Addiction — and relapse — are not the result of a lack of effort, but rather the known symptoms of both a medical and psychosocial problem. In this context, relapse is not indicative of a personal failure but rather a systemic one. Our current treatment regimens still too often fail to prevent relapses because they are still struggling to treat the underlying disease.

Jennifer Martin is a graduate student studying the neurobiology of opiate addiction and relapse; Craig Werner PhD, is a postdoctoral fellow studying the neurobiology of cocaine drug seeking and relapse.

David Dietz, PhD, is the associate professor and chair of the Department of Pharmacology and Toxicology at the University at Buffalo, studying how drugs of abuse "rewire" the brain.