Human beings crave all sorts of things: coffee, sugar, sex, gambling, Xanax, porn, binge-watching TV shows, doomscrolling 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 behaviour 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, demoralising and traumatising 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…