Why addictive cravings are so powerful
By Zoey Lavallee
The neuroscientific picture of addiction overlooks the psychological and social factors that make cravings so hard to resist
Human beings crave all sorts of things: coffee, sugar, sex, gambling, Xanax, porn, binge-watching TV shows, doom scrolling on social media, cocaine, online gaming, heroin, methamphetamines, hoarding. We each find different substances and activities alluring, and we develop distinct habits of choice. Cravings are an especially forceful and persuasive class of desires. When a craving strikes, it can be very tricky to resist or ignore. Sometimes we distract ourselves and move on with little effort. In other instances, it can feel nearly impossible not to act on a craving. What we’re drawn to, and what we’re vulnerable to, seems to reflect our individual personalities, preferences, cultural location, values, identities, coping mechanisms, and other life circumstances. So, why do we crave what we crave, and why are cravings sometimes so forcefully motivating?
One way to see the power of cravings is to think about substance addictions. Substance addictions present the sharpest example of how cravings seem to impact motivation and behavior differently than other desires. Cravings make for one of the most challenging, baffling and terrifying aspects of addiction: no matter how devastating the consequences of ongoing drug use become for someone, as well as for those who love and care for them, no matter whether their addiction is no longer pleasurable, and no matter how adamantly they want and try to manage or stop their drug use, their attempts are continually overwhelmed by intensely motivating desires to engage in the addiction. This loss of control is often taken to be a defining feature of addiction.
Cravings are particularly common with certain drugs, including alcohol, nicotine, opiates and cocaine. Moreover, not only do cravings play this intrusive role in active drug use, but these unwanted desires can arise and be highly motivating even years into recovery from addiction. Craving is a major predictor of relapse. A systematic review of studies assessing the link between craving and substance use by using a method that evaluates craving episodes in real time in daily life found that in 92 per cent of studies craving was linked to substance use and relapse. Cravings can repeatedly override plans and resolutions to moderate or abstain from drug use, and this can be a disruptive, frustrating, demoralizing and traumatizing experience for those who battle these cravings – an experience that for some lasts a lifetime.
A lot of medical and clinical thinking about addictive craving is driven by a certain neuroscientific picture that explains cravings in terms of the effects of drugs on the production of dopamine in the brain. On this picture, the object of a craving is a drug itself or the pleasurable effects that getting high is expected to produce. But, by focusing narrowly on the brain, this view misidentifies the object of craving in addiction, or at least puts too much emphasis on the chemical component. When we look at the social and psychological factors that correlate with addiction, the real object of craving is made salient. In truth, addictive cravings seek out vital emotional experiences. They aim at numbing out, feeling in control, or feeling socially connected. Experiences such as these become particularly valuable and simultaneously elusive under certain environmental conditions. Understanding the object of addictive craving in this way helps to explain why cravings in addiction are so hard to resist.
The craving brain
One of the most popular dopamine-based explanations of craving focuses on reward-learning. While some of our desires may be hardwired, most are learned and are very malleable. The mainstream view is that this learning depends on the dopaminergic system. Phasic dopamine is a reward prediction error signal: it signals to animals, such as us, the difference between the actual amount of reward in the world at a given moment and the amount of reward anticipated. Bursts of dopamine are released when unexpected rewards, or unexpected cues that signal rewards, are encountered. These bursts tell us to act when we come across rewarding objects or related cues in our environment.
Cues can take the form of drug paraphernalia, but also locations, emotions and contexts
Addictive drugs have a pathological effect on this system. While there are various interpretations of the exact role of dopamine, it is well established that psychoactive drugs cause artificially high bursts of phasic dopamine to be released by midbrain dopamine neurons. Increased dopamine activity has been observed, for example, with the ingestion of amphetamines, alcohol, nicotine, opiates, cocaine, cannabis and benzodiazepines. When drugs are encountered, dopamine is released in anticipation of reward, but then the drug itself – due to its chemical effects – causes an additional dopamine boost when ingested, signalling that the drug is ever increasing in value. The result, on this mainstream view, is that these boosts in dopamine trigger cravings that overestimate the amount of reward that is expected, and so explain the excessive motivational pull of cravings.
Through repeated drug use, environmental cues become associated with drug-taking, and eventually these cues themselves start to trigger cravings. Cues are person specific and can take the form of drug paraphernalia such as needles or pipes, but also locations, emotions and contexts that have become associated with substance use. As a result of the long-term effects of this learning process, drug cues can continue to trigger cravings even years after active drug use has stopped, thus the link between craving and relapse.
The long-term effects of drugs on the brain’s reward systems are one reason why addiction is considered to be a chronic, relapsing disorder or neurobiological disease by the orthodox medical conception of addiction. On this view, addictive cravings are desires for the high produced by drug ingestion. These desires are abnormally strong, dysfunctional caused, and they come to dominate the decision-making system.
Neuroscience tells only part of the story
While neuroscience offers insight into the brain mechanisms underlying substance use, explanations of craving have been heavily skewed towards studying the brain, with research funding being disproportionately allocated to biological causes. This promotes an incomplete and potentially misleading picture of addictive cravings. It is like studying humour by focusing on the brainstem nuclei that trigger laughter. Dopamine circuits operate in a larger context. To understand addiction, we must also look at experience, thought processes, behaviour, and life conditions. From this broader perspective, addictive cravings do not look like simple switches in the brain. Research shows that addiction is not automatic and, in most cases, not chronic.
First, it is not automatic. If excessively strong cravings were simply the result of drugs corrupting the reward systems in the brain, they should be produced across individuals who use drugs repeatedly over time. This is not the case. Most drug use does not lead to addiction, even the drugs that are often considered ‘highly addictive’, such as cocaine. One survey in the United States found that 19.4 per cent of people 12 and older reported past-month ‘illicit’ drug use, whereas only 3 per cent qualified for a past-year illicit drug use disorder. Drugs aren’t inherently dangerous, and not all drug use has negative consequences.
Why do cravings seem to weaken or desist over time for many addicted people?
Second, most cases of addiction aren’t chronic. Most people who do develop an addiction ‘age out’ of it without professional intervention. Over time, whether with the assistance of some form of treatment or not, most people decide to reduce or abstain from drug use, and they do so. For example, the majority of people who have an alcohol use disorder reduce or resolve problematic use over time. The case of Vietnam veterans and heroin addiction provides a concrete illustration of high remission: 20 per cent of US soldiers returning from Vietnam met the criteria for heroin addiction diagnosis while they were in active service, while only 1 per cent did before serving; of those who developed an addiction, 95 per cent were in remission within a year of returning home.