For decades, the idea of an addictive personality has shaped how families, schools and clinics talk about drug and alcohol problems. Now two of the largest genetic studies ever carried out suggest the idea is far too simple. There is no single addictive personality. There are several routes to addiction, and personality is only one part of the map.
The latest evidence comes from a paper published in Nature on 2 September 2026. Ted Schwaba and colleagues pooled data from 46 cohorts, with between 611,037 and 1.14 million participants for each of the Big Five personality traits. They identified 1,260 genetic variants linked to personality, and 824 of them were new. Many people assumed such work would finally prove the addictive personality theory.
Three years earlier, Alexander Hatoum and more than 150 colleagues analysed data from over 1.1 million people. They found one general risk factor shared by problem alcohol and tobacco use, cannabis use disorder and opioid use disorder. They also found risks that belong to individual substances. In short, vulnerability can be shared, but there is no single addiction gene.
What personality and addiction have in common genetically
Some of the genetic signals overlap with substance use. Genetic liability to conscientiousness tracks with less substance use across substances, with a mean correlation of 0.21 in the protective direction. Higher neuroticism links to several substance outcomes, especially alcohol dependence. Higher agreeableness is generally protective.
The effects are small, though. The Nature authors report that common variants explain only 4.8 to 9.3 per cent of the variance in each trait. For extraversion, the typical effect of a single variant is 0.009 standard deviations, which is like scoring at the 50.35th percentile instead of the 50th. Personality is built from thousands of tiny nudges, and nothing in the data points to an addictive personality hiding in the genome.
Why one addictive personality does not hold up
The label has always been circular. People drank because they had an alcoholic personality, and the proof was that they drank. Meanwhile, the people placed under that one label looked very different. Some were impulsive and sensation seeking. Others were anxious, inhibited or depressed.
Researchers have long described these separate roads. Cloninger proposed an earlier onset, more heritable pathway for alcoholism and a later onset, anxious pathway. Edward Khantzian asked why a particular drug suits a particular person. Opioids may quiet rage, stimulants may lend energy and alcohol may ease worry. Sándor Radó made a similar point in 1933, noting that people often take drugs to stop feeling bad rather than to feel good.
So some people seek stimulation while others seek relief. Epidemiological studies suggest that about half of the risk for addiction is genetic, which is higher than the share for type 2 diabetes or hypertension. Yet no single trait explains who experiments, who finds a drug useful and who cannot stop.
Genes load the dice, but exposure still decides
Genes shape vulnerability, but exposure remains required. With no first use, there is no addiction. That explains the old claim that alcoholism “skips a generation”. Genes do not skip anyone. A child who saw too much may avoid alcohol entirely, and a grandchild who drinks can then make the family history look as if it jumped.
The drug matters as well. Fentanyl can addict anyone, even a careful anaesthetist. Alcohol can trap a conscientious doctor. Potency, availability, age at first exposure, trauma, peers and brain adaptation all play a part. Behaviour during addiction should not be mistaken for character, either. Someone lying to obtain heroin is not necessarily a dishonest person, because dependence makes honesty very costly.
Why a gene score cannot say who will become addicted
Headlines about genes can mislead, so the limits matter. No DNA test can find an addictive personality in a single person. A polygenic score is not a diagnosis and it is no crystal ball. The Nature authors state plainly that these scores cannot predict an individual’s future behaviour. Genetic associations act as probabilities across large groups of people, not as verdicts on one person.
Accuracy also varies. Around 95 per cent of participants in the Nature analysis had European like genomes, and prediction is expected to weaken when ancestry differs from the discovery sample. The paper also stresses that personality is substantially influenced by a person’s environment. The addictive personality idea ignores all of this.
What this means for prevention
If risk runs along several pathways, prevention can work on several fronts. A commentary on the research in Psychology Today sets out the logic. Delay first exposure to substances. Reduce access to potent drugs. Treat psychiatric illness early. Strengthen families and schools.
The same thinking applies to young people. A sensation seeking teenager may need structure, alternative rewards and less access to drugs. Anxiety, ADHD, depression and insomnia need proper treatment, not dismissal as excuses.
Dropping the addictive personality label also removes a stigma. Risk is spread across the whole population, so the useful question is not what kind of person becomes addicted. It is which pathway, which drug and which stage of life. That answer is less catchy, but it is more accurate and far more useful.
(Source: WRD News)