The term "addictive personality" is widely used. Are some people really more prone to developing an addiction?

During the 1990s,  the term "addictive personality" was used by some pharmaceutical companies – and, perhaps ironically, to promote addictive painkiller drugs.

While marketing the opioid prescription drug OxyContin, for example, US pharmaceutical company Purdue Pharma instructed their representatives to tell doctors that only people with an "addictive personality" were at risk of becoming addicted, despite knowing that it was highly addictive and widely abused. Highly addictive drugs such as OxyContin and the opioid fentanyl are blamed for fuelling the opioid crisis in the US, which caused more than half a million deaths between 1999 and 2020.

The idea that your personality determines whether or not you become addicted to a substance would have "suited the pharmaceutical industry very well", says Ian Hamilton, associate professor in addiction at the University of York in the UK. "It kind of lets them off the hook. The message is: 'if you're weak enough to develop a problem with our product, it's due to your personality, it's nothing to do with us'."

But is there such a thing as an addictive personality? Are some people really more prone to developing an addiction?

Many psychiatrists and addiction experts say there is no scientific evidence supporting the idea. They also warn that the concept is harmful as it suggests that people have little to no control over whether they become addicted.

They do note that there are some links between certain personality traits and addiction, but these are far more complex than the "addictive personality" claim often indicates.

Mark Griffiths, distinguished professor of behavioural addiction at Nottingham Trent University in the UK, describes the "addictive personality" as a "complete myth".

"For there to be such a thing as an addictive personality, what you're saying is that there's a trait that is predictive of addiction and addiction alone," says Griffiths. "There is no scientific evidence that there is a trait that predicts addiction and addiction alone."

The addictive personality "is a black-and-white way of thinking about something that's highly complex", says Anshul Swami, a psychiatrist in adult mental health and addictions at Nightingale Hospital in London. "There is no one personality type [predictive of addiction] and there is no one person who is the same as another addict."

That's not to say that certain personality traits are not associated "with the acquisition, development and maintenance of addictive behaviours", says Griffiths.

Neuroticism, for example, tends to be associated with many forms of addiction. Neuroticism is one of the Big Five personality traits and is defined as the extent to which a person reacts to perceived threats and stressful situations. Highly neurotic people are anxious and prone to negative thoughts. According to an analysis of 175 studies, substance abuse disorders are associated with high levels of neuroticism and low levels of conscientiousness (the extent to which a person exhibits self-control). Research has found that behavioural addictions, such as internet and exercise addiction and compulsive buying, are also associated with neuroticism.

"If you're neurotic, you're highly anxious," says Griffiths. "People tend to use addictive behaviours or substances as a way to manage their neurotic traits. Most addictions are about coping and are symptomatic of other underlying problems, such as depression or neuroticism."

But there is no research showing that all people with addictions suffer from neuroticism, says Griffiths. "I can find many people who are neurotic and aren't addicts. Neuroticism is associated with, but it is not predictive of, addiction."

As Hamilton points out it can be "fiendishly difficult" to untangle which comes first when it comes to a substance dependency. "What you see is elevated rates of depression or anxiety among people who become dependent on drugs. But then it becomes chicken and egg. Was it neuroticism which led the person to the drug, or did their addiction to cocaine over a long period of time lower their mood?"

"Addictions are very nuanced and multifactorial," says Swami. Research shows that addictions can be influenced by both genetics and a wide range of environmental factors, including peer pressure, early exposure to substances and physical or sexual abuse.

A 2018 study found that the ancient retrovirus HK2, which lies close to the gene involved in the release of the chemical dopamine, is more frequently found in drug addicts. People suffering from substance abuse disorders were up to two to three times more likely to have HK2 integrated in their genome, indicating a strong association with addiction, the researchers concluded.

Swami says this study does not provide any evidence that some people have a more "addictive personality" than others.

"This HK2 preliminary finding does not explain why an increasing number of patients in later life develop addiction," he says. "If they had it and it was associative or causative it would surely express sooner."

Gender is another risk factor for addiction. In the US, 11.5% of men and boys have a substance abuse addiction compared to 6.4% of women and girls. There are several reasons, says Hamilton. "Men, particularly teenage boys, tend to be bigger on risk-taking and more impulsive," he says. Impulsivity is another trait associated with addiction. But Hamilton warns that there may be significant data gaps as women are less likely to seek treatment due to childcare issues and stigma.

Research shows that a person's environment and upbringing also strongly influences their risk for addiction. One study found that opiate users were 2.7 times more likely to have a history of childhood abuse, either sexual, physical or both, than non-opiate users. People who experienced four adverse childhood experiences, such as physical, sexual or emotional abuse or loss of a parent, were three times as likely to report having alcohol problems in adulthood, according to a 2022 study.

"Psychosocial factors like violence, sexual abuse and emotional neglect are strongly associated with addiction," says Swami. "Many people will say 'I've got a history of addiction, it's because of my genetics'. But when you drill down in their clinical history, you find that there was a lot of drinking, neglect, abuse, trauma and deprivation. That has been passed down from generation to generation and has surfaced as an addiction."

Despite the lack of scientific evidence to support it, the term "addictive personality" continues to be widely used. "We've got to be careful with language as people do internalise it," says Hamilton. "The idea of the addictive personality robs you of any hope… it says that this is the trajectory you have to go down and that you have no control over it.

Swami agrees that the concept is unrealistically "fatalistic". "It stops people from taking responsibility and ownership of their problem and finding constructive solutions to getting better," he says.

Griffiths says many people with addictions will use the idea of the addictive personality as a "justification for their behaviour". "When someone says 'I've got an addictive personality', what they're actually saying is 'I can never be cured'," he says.

"Addictions are highly complex biological, psychological, social illnesses, just like every other illness on the planet," says Swami. "Everyone is looking for a simple answer, but there isn't one."

BBC

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